Integrated Water Master Plan - Aurora, Colorado · The Integrated Water Master Plan (IWMP) integrates short-term and long-range planning across the Water Resources, Treatment, and

CITY OF AURORA//Integrated Water Master Plan

MWH FINAL REPORT SEPTEMBER 2017//PAGE i

Table of Contents

1.0 Executive Summary ..................................................................................................... 1-6

1.1 Introduction .............................................................................................................. 1-6 1.2 Planning Scenarios and Demand Projections .......................................................... 1-6 1.3 Water Resources ..................................................................................................... 1-8 1.4 Water Treatment .................................................................................................... 1-10 1.5 Distribution ............................................................................................................. 1-13 1.6 Integrated 10 Year CIP Prioritization and Results.................................................. 1-14 1.7 Summary ............................................................................................................... 1-16

2.0 Project Introduction ..................................................................................................... 2-1

2.1 Background ............................................................................................................. 2-1 2.2 Overview of the Aurora Water System ..................................................................... 2-1 2.3 Authorization ............................................................................................................ 2-2

3.0 Demand Planning ......................................................................................................... 3-1

3.1 Water Demands ....................................................................................................... 3-1 3.2 Water Conservation ................................................................................................. 3-3

4.0 Planning Framework .................................................................................................... 4-1

4.1 Planning Horizon ..................................................................................................... 4-1 4.2 Planning Scenarios .................................................................................................. 4-1 4.3 Risk Identification ..................................................................................................... 4-3 4.4 IWMP Assumptions ................................................................................................. 4-4

5.0 Water Resources .......................................................................................................... 5-1

5.1 Introduction .............................................................................................................. 5-1 5.2 Basis of Planning ..................................................................................................... 5-1 5.3 Water Resources Modeling ..................................................................................... 5-1 5.4 Vulnerability and Planning Scenarios Assessment .................................................. 5-3 5.5 Water Resources Projects ....................................................................................... 5-5 5.6 Water Resources Portfolios ................................................................................... 5-15 5.7 Water Resources Plan ........................................................................................... 5-17

6.0 Treatment ...................................................................................................................... 6-1

6.1 System Design Requirements ................................................................................. 6-1 6.2 Existing System Demands and Capacity ................................................................. 6-1 6.3 Future System Demands and Capacity Required .................................................... 6-4 6.4 Proposed Capital Projects ....................................................................................... 6-6

6.4.1 Rampart Raw Water System .............................................................................. 6-6 6.4.2 Griswold WPF Capacity Recovery ...................................................................... 6-6 6.4.3 Binney WPF – South Platte Train Build-Out ....................................................... 6-7

6.5 Findings and Recommendations ........................................................................... 6-10 6.5.1 Planning Scenario 1 (Baseline Plus)................................................................. 6-13 6.5.2 Planning Scenario 2 (Fast Growth) ................................................................... 6-14 6.5.3 Planning Scenario 3 (Fast and Hot) .................................................................. 6-15 6.5.4 Planning Scenario 4 (Hot Baseline) .................................................................. 6-16


MWH FINAL REPORT SEPTEMBER 2017//PAGE ii

7.0 Distribution ................................................................................................................... 7-1

7.1 System Design Requirements ................................................................................. 7-1 7.2 Near-Term Projects ................................................................................................. 7-8 7.3 Long-Term Projects ................................................................................................. 7-9 7.4 Capital Improvement Plan ..................................................................................... 7-10

8.0 CIP Prioritization and Results ..................................................................................... 8-1

8.1 CIP Prioritization ...................................................................................................... 8-1 8.2 Approach ................................................................................................................. 8-1

8.2.1 Overview ............................................................................................................. 8-1 8.2.2 Criteria Determination, Weighting, and Scoring .................................................. 8-2 8.2.3 Additional Prioritization Analyses – Schedule Optimization ............................... 8-5

8.3 CIP Results .............................................................................................................. 8-5

9.0 References .................................................................................................................... 9-1


MWH FINAL REPORT SEPTEMBER 2017//PAGE iii

List of Tables

Table 1-1. IWMP Planning Scenario Characteristics ................................................................ 1-7 Table 1-2. Key Metrics for Water Resources System Performance Analysis ............................ 1-8 Table 1-3. Existing Raw Water Supply and Treatment Capacities .......................................... 1-11 Table 3-1. Annual Demand for Future Years by Exceedance Probability ................................. 3-2 Table 3-2. Conservation Measures Included in Program B ...................................................... 3-3 Table 3-3. Projected GPCD Change with Conservation Program B as Compared to 2014

GPCD ...................................................................................................................... 3-4 Table 4-1. IWMP Planning Scenario Characteristics ................................................................ 4-2 Table 4-2. CIP Growth and Climate Related Risks ................................................................... 4-4 Table 5-1. Drought Response Stages and Watering Restrictions ............................................. 5-2 Table 5-2. Drought Response Stage Thresholds for Current Demand and Storage

Conditions ................................................................................................................ 5-2 Table 5-3. Key Metrics for Water Resources System Performance Analysis ............................ 5-3 Table 5-4. Potential Water Resources Supply Projects for Analysis in the IWMP .................... 5-6 Table 5-5. Potential Delivery System Improvement Projects for Analysis in the IWMP .......... 5-11 Table 5-6. Cost Estimates for Potential Water Resources Supply Projects ............................ 5-14 Table 5-7. Cost Estimates for Potential Delivery System Improvement Projects .................... 5-14 Table 5-8. Balanced Storage/Supply Portfolios for 2070 Gap ................................................ 5-17 Table 6-1. Existing Raw Water Supply and Treatment Capacities ............................................ 6-3 Table 6-2. Water Demands by Year and Planning Scenario..................................................... 6-4 Table 6-3. Water Demands Satisfied by Existing Capacity ....................................................... 6-5 Table 6-4. Capital Costs of Proposed Treatment and Water Resources Projects Impacting

Capacity ................................................................................................................. 6-11 Table 6-5. Cumulative Raw Water Supply and Treatment Capacities .................................... 6-12 Table 7-1. 2020 T&D Improvement Projects ............................................................................. 7-2 Table 7-2. 2035 T&D Improvement Projects ............................................................................. 7-3 Table 7-3. 2070 T&D Improvement Projects ............................................................................. 7-5 Table 7-4. 2070 Pump Station Improvement Projects .............................................................. 7-7 Table 7-5. 2070 Storage Improvement Projects ....................................................................... 7-7 Table 7-6. Distribution CIP Total Cost by Year and Project Category ..................................... 7-10 Table 8-1. Final TBL Prioritization Criteria ................................................................................ 8-4 Table 8-2. Aurora Water 10 Year CIP Cash Flow Summary* ................................................... 8-8


MWH FINAL REPORT SEPTEMBER 2017//PAGE iv

List of Figures

Figure 1-1. Range of Annual Demand Projections ..................................................................... 1-7 Figure 1-2. Summary of Water Resources Portfolios for Each Planning Future ........................ 1-9 Figure 1-3. Peak Day Water Demands by Year and Total Existing WPF Production Capacity 1-12 Figure 1-4. Planning Scenario 2 Project Timing ....................................................................... 1-13 Figure 1-5. Aurora Water 10 Year CIP, Spend by Year ........................................................... 1-14 Figure 1-6. Aurora Water 10 Year CIP Summary Gantt Chart ................................................. 1-15 Figure 3-1. Range of Annual Demand Projections ..................................................................... 3-2 Figure 4-1. System-wide Annual Raw Water Demands at WPF Intakes for IWMP Planning

Scenarios ................................................................................................................. 4-2 Figure 4-2. Risk Workshop Process ........................................................................................... 4-3 Figure 5-1. Non-Restriction Frequency System Performance with Selected System Risks ....... 5-5 Figure 5-2. Overview of Portfolio Development Process .......................................................... 5-15 Figure 5-3. Summary of CIP Portfolios for Each Planning Future ............................................ 5-16 Figure 5-4. Aurora Water Resources Strategies and Threats .................................................. 5-18 Figure 5-5. Factors to Track for Adaptive Water Supply Planning ........................................... 5-19 Figure 6-1. Ideal Annual System Demand and WISE Distribution ............................................. 6-2 Figure 6-2. Water Demands by Year and Planning Scenario..................................................... 6-5 Figure 6-3. Planning Scenario 1 (Baseline Plus) Project Timing .............................................. 6-14 Figure 6-4. Planning Scenario 2 (Fast Growth) Project Timing ................................................ 6-15 Figure 6-5. Planning Scenario 3 (Fast and Hot) Project Timing ............................................... 6-16 Figure 6-6. Planning Scenario 4 (Hot Baseline) Project Timing ............................................... 6-17 Figure 8-1. Initial Prioritization Process ...................................................................................... 8-2 Figure 8-2. Aurora Water 10 Year CIP, Total by Discipline ........................................................ 8-6 Figure 8-3. Aurora Water 10 Year CIP, Spend by Year ............................................................. 8-6 Figure 8-4. Aurora Water 10 Year CIP Summary Gantt Chart ................................................... 8-7


MWH FINAL REPORT SEPTEMBER 2017//PAGE v

List of Abbreviations

ac-ft acre-feet

ac-ft/yr acre-feet per year

AMI Automated Meter Infrastructure

AR Aurora Reservoir

ARR Aquifer Recharge and Recovery

AW Aurora Water

BBC BBC Research & Consulting

CII Commercial, Institutional, and Industrial

CIP Capital Improvement Plan

DMS data management system

FTW filter-to-waste

GPCD gallons per capita per day

HE high efficiency

IWMP Integrated Water Master Plan

LOS level of service

LP large property

MGD million gallons per day

MWH MWH Americas, Inc.

O&M operation and maintenance

OPCC Opinion of Probable Construction Costs

OPT-Search optimization-based searches

PCCP pre-stressed concrete cylinder pipe

PS pump station

PW Prairie Waters

RBF riverbank filtration

RMF Risk Management Framework

SP South Platte

SQL Structured Query Language

TAZ Transportation Analysis Zone

T&D Transmission and Distribution

TDS Total Dissolved Solids

TWMP Treated Water Master Plan

UHET ultra-high-efficiency toilet

VFD variable frequency drive

WISE Water Infrastructure and Supply Efficiency

WNA water needs assessment

WPF water purification facility

WRTM Water Resources Technical Memorandum


MWH FINAL REPORT SEPTEMBER 2017//PAGE 1-6

1.0 Executive Summary

1.1 Introduction

The Integrated Water Master Plan (IWMP) integrates short-term and long-range planning across the

Water Resources, Treatment, and Transmission and Distribution (T&D) disciplines within Aurora

Water. An integrated Capital Improvement Plan (CIP) focused on growth-related projects was

developed using consistent key assumptions and the same planning horizon for all disciplines. Long

range plans were also developed for each of the disciplines to address uncertainty around future

growth and climate variability.

1.2 Planning Scenarios and Demand Projections

The IWMP addresses water needs and planning strategies from 2016 to 2070. Planning milestones

were set at 2025, 2035, and 2050 to evaluate interim needs and solutions. Four planning scenarios

were developed to cover a range of population growth, economic growth, future climate, and future

conservation program assumptions. Table 1-1 shows a summary of the assumptions included in each

planning scenario and the associated system-wide raw water demands.

Demand projections were created using a demand forecasting model that incorporated population,

land use, development density, projections of water use and water use intensity among different classes

of customers, employment factors, water pricing, and weather conditions – 19 variables in all.

Demands were estimated for different confidence intervals, representing the uncertainty surrounding

the demand model parameters used to develop the future demand projections. Figure 1-1 shows the

planning scenario demands as well as the base forecast and its associated 90% and 99% confidence

intervals.

A review of the water conservation program was conducted to identify additional conservation

measures that would be cost-effective to add to the existing program. Three future conservation

programs were analyzed and resulted in the selection of Program B, which includes additional

conservation measures that provide the greatest benefit-cost and can be readily implemented by

Aurora Water. When combined with savings associated with changes in the plumbing code, Program

B will reduce 2015 per capita demands by about 10 percent by 2050.

Simulations of Aurora Water’s water supply system were performed using a Paleo hydrologic ensemble

representing current climate conditions and a Modified Paleo hydrologic ensemble representing a

hotter, drier climate that would result in approximately 19 percent reduction in mean streamflow.



Table 1-1. IWMP Planning Scenario Characteristics

Characteristics Hydrology Ensemble

Annual Demands (ac-ft/year) at WPF Intakes**

2015* 2025 2035 2050 2070

1) Baseline Plus

Average growth, weather, and hydrology – enhanced conservation (Program B)

Paleo 49,750 55,172 61,313 75,928 95,332

2) Fast Growth

High growth, average weather, and hydrology – enhanced conservation (Program B)

Paleo 51,290 59,438 68,301 87,194 115,811

3) Fast and Hot

High growth, hot/dry weather, and hot/dry hydrology – enhanced conservation (Program B)

Modified Paleo

57,247 66,429 76,477 98,295 130,158

4) Hot Baseline

Average growth, hot/dry weather, and hot/dry hydrology – enhanced conservation (Program B)

Modified Paleo

55,495 61,620 68,550 85,367 106,972

*Forecast was prepared in 2014; actual 2015 demand was 47,540 ac-ft. **Demands for finished water from the water purification facilities are 3 percent less than the values in this table.

Figure 1-1. Range of Annual Demand Projections

Planning Scenario 2 (Fast Growth) was selected as the basis for IWMP CIP development. Planning

Scenario 3 (Fast and Hot) generated demands that fell outside the 90 percent confidence range of the

base demand forecast, and was thus eliminated from most IWMP analyses.

Future maximum-day and maximum-hour demands were estimated based on analysis of historical

data and anticipated future water use, demographic trends, and climate conditions. Maximum-day

demand was estimated as 3.4 times average winter day demand and maximum-hour demand was

estimated as 1.6 times maximum-day demand.



1.3 Water Resources

The Aurora Water supply simulation model (Excel-CRAM) was used to quantify impacts of water

resource risks on raw water system performance. Baseline models were developed for existing (2015)

and future (2070) conditions and include currently owned water rights and current operation of Aurora

Water facilities, historical operation of other entities in the source water basins, and all existing water

projects (e.g., reservoirs and storage accounts). Aurora Water’s drought response program was also

included in the Baseline Excel-CRAM model.

Water resources system performance was evaluated using metrics and acceptable levels of service

(LOS). Selected metrics and LOS goals are shown in Table 1-2.

Table 1-2. Key Metrics for Water Resources System Performance Analysis

Metric Name Description Target Acceptable

LOS (1) LOS Narrative

No-Restriction

Frequency

Probability of being in

“Normal Conditions” above

the Stage I threshold

storage level at the

beginning of any May

Stage I storage

level >0.80 (80%)

There will be no additional

outdoor watering restrictions (2)

in a minimum of 8 years in 10;

or, there will be some form of

drought restrictions no more

than 2 years in 10

Reduced

Supply

Reliability

Probability of meeting

reduced customer demands

with drought response

watering restrictions on a

monthly basis

Demands after

reductions

from drought

restrictions

have been

applied

=1.0 (100%)

Will always meet demands that

are reduced due to any level of

drought restrictions

WISE (3)

Supply

Reliability

Probability of meeting WISE

obligations on a monthly

basis

10,000 ac-ft

annual

demand

= 1.0 (100%) Will always meet WISE supply

obligations

(1) Metrics range from 0 to 1.0, where 1.0 indicates the best possible performance and 0 represents the worst possible

performance. Acceptable performance is greater than the acceptable LOS. (2) No additional restrictions beyond the three day per week voluntary watering restrictions that are permanently in

place under “Normal Drought Stage” conditions. (3) Water Infrastructure and Supply Efficiency (WISE) Partnership.

A water needs assessment was conducted to determine the risks that are critical to Aurora Water’s

system and the years in which new improvements will be necessary. Key identified risks include

demand increases, climate variability, and loss of Colorado River supplies. Aurora Water’s current

system will be unable to meet LOS goals by approximately 2025 if system risks do not occur. If system

risks are applied in the analysis, Aurora Water’s current system will be unable to meet LOS goals in

earlier years.

Portfolios (i.e., collections of individual projects) were created to meet future water needs with the

established LOS goals under the different planning scenarios and at different future dates. Nineteen

potential water resources supply projects (e.g., reservoir storage, gravel lakes, water rights acquisitions,

and agricultural water leases) and seven delivery system improvement projects were selected for

consideration in building water resources portfolios.



Figure 1-2 summarizes the water resources portfolios selected across three planning scenarios and

four planning years. The green, blue, orange, or yellow color indicates that the project is needed by

the corresponding future year (2025, 2035, 2050, and 2070, respectively). The gray color indicates that

the project is included in the portfolio but would have been completed at an earlier planning year. The

white color indicates the project is not required for that planning scenario and year.

It was not possible to assemble portfolios from all the available projects to meet the LOS goals in

2070 for Planning Scenarios 2 and 4. A supplemental optimization analysis was performed to

determine how the 2070 Gap could be filled using conceptual, non-specific types of projects such as

additional water rights, groundwater, additional capacity in Prairie Waters, additional storage, and

advanced treatment of Lower South Platte water. The 2070 Base Gap Projects are represented as the

beige color in Figure 1-2.

Figure 1-2. Summary of Water Resources Portfolios for Each Planning Future



The IWMP analyses showed that Aurora Water’s diversified water resources system provides a strong

basis for addressing future challenges. Many options are available for meeting increased demands and

risks in the future. However, all of the options come with implementation challenges.

Aurora Water is adopting strategies to implement the water resources recommendations in the IWMP.

These strategies are based on the need to position the organization to meet its customer water needs

in a growing region with an uncertain future climate, aging infrastructure, and increasing competition

for scarce water supplies. The strategy of continuous planning and adaptation requires Aurora Water

to constantly monitor growth in its service area, water demand, climate variability, and regulations and

legislative initiatives that could affect the ability to manage water and implement projects.

1.4 Water Treatment

Recommended Water Purification Facility (WPF) improvements were based on the 2012 Treated Water

Master Plan (CH2M Hill, 2012) and the 2015 Aurora Water Treatment Capacity Capital Improvements Plan

Review and Update (CH2M Hill, 2015). Table 1-3 summarizes capacities of existing water treatment and

related raw water transmission infrastructure.



Table 1-3. Existing Raw Water Supply and Treatment Capacities

(1) Griswold WPF Wemlinger WPF

Binney WPF Total

System Aurora

Reservoir Train South Platte Train

RAW WATER SUPPLY CAPACITY (MGD)

Gravity

Pipelines Rampart: 59/20 (2)

Rampart: 66/50 (3)

Aurora Reservoir: 130/21 (4)

Aurora

Reservoir: 80 (5)

Pumped

Systems

Quincy:

Firm: 5 (6)

Hydraulic: 24

Installed: 36

PW (7) Pipeline: 50

PW Pumps: 20 (8)

Wells Cherry Creek Well

Field: 9

PW Riverbank Filtration: 10.8

PW Aquifer Storage and Recovery: 4-5

Total

Sustainable

Supply

34 (9) 71 80 10.8 195.8

TREATMENT CAPACITY (MGD) (10)

Rated 80 (11) 80 33.3 50

Filtration (one

filter offline) 100 80 33.3 50

Solids Handling 65 (11) 80 Not limiting (12) Not limiting (12)

Peak

Sustainable 65 80 33.3 50

PEAK SUSTAINABLE PRODUCTION (MGD)

Peak

Sustainable

Production (13)

34 71 33.3 10.8 149.1

NOTES: (1) These values in the table are for the purpose of achieving total maximum pipeline capacities and do not

represent true supply capacities or limitations to the individual treatment facilities. (2) The Rampart supply to Griswold WPF is limited to 20 MGD if water is also being supplied to Wemlinger WPF.

Otherwise, the supply to Griswold has a maximum of 59 MGD. (3) The Rampart supply to Wemlinger is limited to 50 MGD if water is also being supplied to Griswold WPF. When

Rampart is only supplying raw water to Wemlinger, the capacity is 66 MGD. (4) The hydraulic capacity of the Aurora Reservoir Pipeline is 130 MGD; however, in order to operate properly,

Wemlinger WPF limits the Aurora Reservoir contribution to 30% of the total Wemlinger feed flow. Because the maximum contribution available from Rampart Reservoir is 50 MGD when Griswold is also being supplied, the maximum flow from Aurora Reservoir is 21 MGD and the Wemlinger WPF maximum is 71 MGD.

(5) The pipeline is sized for 80 MGD but the actual capacity depends on the level in Aurora Reservoir. (6) Due to taste and odor events, flow from Quincy Reservoir is generally limited to 15% of total production. (7) PW – Prairie Waters (8) Prairie Waters Pump Stations are designed for expansion to 50 MGD. (9) Total sustained raw water supply to Griswold WPF is 20 MGD from Rampart, 9 MGD from the Cherry Creek

Wells and 5 MGD (i.e., 15% of total production) from Quincy Reservoir. (10) Treatment capacity includes work at Binney WPF that will be completed in 2016 (filters and solids handling). (11) Rated capacity at Griswold WPF is limited by the filter backwash component of the solids handling system;

filters are rated at 100 MGD. (12) Solids Management Project currently under construction will render both AR and SP solids as not limiting. (13) Raw water quality can affect sustainable capacities at Wemlinger and Griswold since they are direct filtration

facilities.



The peak day demands for each planning scenario and the year in which the peak day demands are

anticipated to exceed the existing system capacity are shown in Figure 1-3.

Figure 1-3. Peak Day Water Demands by Year and Total Existing WPF Production Capacity

The existing treatment system has sufficient capacity to meet peak day demands for Planning Scenario

2 through 2044. Proposed timing of the projects required to meet peak day demands under Planning

Scenario 2 is presented in Figure 1-4. With all improvements shown below, there will be a treatment

capacity deficit beginning in 2069 for Planning Scenario 2. It should be noted that the timing associated

with the projects presented in Figure 1-4 is based on Treatment requirements for meeting peak day

demands; integrated CIP timing is based on the discipline with the earliest need. Specifically, the Water

Resources CIP Portfolio accelerates the required timing for the Wemlinger Blended Water Pipeline

(2035), PWP Expansion 1 (2025), PWP Expansion 2 (2035), and PWP Expansion 3 (2050).

0

50

100

150

200

250

2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070

De

man

ds/

Cap

acit

y in

MG

D

Scenario 1 Peak Day Demand Scenario 1 Peak Day = Capacity




Peak Sustainable Production Peak Sustainable Production, Binney Offline

Existing Capacity Existing Capacity Reached Reached, Binney Offline

Scenario 1 2056 2021Scenario 2 2044 Already ReachedScenario 3 2036 Already ReachedScenario 4 2046 Already Reached



Figure 1-4. Planning Scenario 2 Project Timing

1.5 Distribution

The T&D projects needed to adequately serve projected population growth and associated demands

up to 2070 were identified in the IWMP and further refined in the T&D CIP Refinement Study

(Refinement Study), conducted by Water Plans, Inc. Projects were developed and verified using the

City’s all pipes distribution system hydraulic model. The demands used for the Refinement Study were

updated demands that utilized more recent water use data. The updated demands were slightly higher

than Planning Scenario 2 demands with a projected max day demand of 266.4 MGD for 2070. To

better reflect anticipated demands from high-use developments, specific model nodes were adjusted

using estimated demands for these developments. The high-use developments collectively have an

estimated max day demand of 8.1 MGD, which would result in a total system max day demand of

274.5 MGD in 2070.

In order to accommodate future growth while utilizing the existing treatment capacity, the capital

improvements focus on conveying supply from Griswold and Wemlinger WTPs to the northeastern

portion of the City’s service area. System improvements include a 60” pipeline conveying flows from

Wemlinger and Griswold northeast along with a new reservoir located in Pressure Zone 3 that will

serve the northeastern portion of the water system.

T&D improvements needed through 2020 aim to reinforce the existing service area while laying the

foundation for future growth in the north. Through 2035, system improvements support the

expansion of the service area and deliver associated demands by reinforcing and building off of the

existing distribution system. By 2070 a significant amount of system improvements are focused on the

eastern and northeastern side of the City to accommodate future growth.

PWP Expansion 1155 MGD in 2045

Wemlinger Blended Water Pipeline

159 MGD in 2047

PWP Expansion 2172 MGD in 2049 PWP Expansion 3

184 MGD in 2055

PWP Storage Project - Terminal Reservoir

188 MGD in 2060

Holly Street Pump Station

195 MGD in 2061

Griswold Improvements

210 MGD in 2064

Treatment Capacity Exceeded in 2069

Redundant power at the PWP stations,

20150

50

100

150

200

250

300

2015 2025 2035 2045 2055 2065

De

man

ds/

Cap

acit

y in

MG

DScenario 2 Peak Day Demand Scenario 2 Peak Sustained System Capacity



1.6 Integrated 10 Year CIP Prioritization and Results

An integrated 10 year CIP comprised of water resources, treatment, and T&D projects was prepared.

Projects were prioritized using a multi-criteria analysis approach in which each project was scored

based on consistent triple bottom line criteria in economic, environmental, and social categories as

well as criteria related to project performance in meeting the level of service goals for the associated

discipline (water resources, treatment, or distribution). Criteria, criteria weights, and scores for each

individual project were developed in workshops with Aurora Water staff. Expert Choice software

was used to perform the multi-criteria analysis that resulted in the prioritization of projects.

The 10 year CIP was developed using a portfolio optimization spreadsheet that sequenced projects

based on their benefit score, the year of need, and a capital budget annual limit of $39 million, which

was established by Aurora Water leadership. The prioritized 10 year CIP for the IWMP is summarized

in Figure 1-5 and Figure 1-6.

Note: The updated T&D CIP costs from the Refinement Study are not reflected in this figure. See Section 7 for the updated T&D costs.

Figure 1-5. Aurora Water 10 Year CIP, Spend by Year

$-

$5

$10

$15

$20

$25

$30

$35

$40

$45

2017 2018 2019 2020 2021 2022 2023 2024 2025 2026

Mill

ion

s

Aurora Water 10 Year CIP | Spend by Year

Water Resources 10-Yr T&D 10-Yr Treatment 10-Yr Water Rights Acquisitions Target Funding Limit



Notes: Blue: Water Resources Projects, Grey: T&D Projects, Green: Treatment Projects. The updated T&D CIP projects from the Refinement Study are not reflected in this figure. See Section 7 for the updated T&D projects.

Figure 1-6. Aurora Water 10 Year CIP Summary Gantt Chart



1.7 Summary

The IWMP for Aurora Water provides an integrated 10 year CIP and a coordinated long range plan

for water resources, water treatment, and distribution system improvements through 2070. The CIP

addresses immediate concerns and opportunities, while the long range plans incorporate contingencies

for uncertainty around the key drivers of growth and climate variability.

Aurora Water plans to update the IWMP at approximately 5 year intervals to address changes in

population and demand forecasts, growth potential in the service area, climate conditions,

conservation effectiveness, new water supply opportunities, and other factors that affect the water

system. The analytical tools developed for the IWMP will facilitate future updates. These include the

DMS for executing the Excel-CRAM model; the project database; the Expert Choice model for

project evaluation; and the portfolio optimization model for building an integrated, prioritized CIP

with projects from all three disciplines.



2.0 Project Introduction

2.1 Background

This report presents the IWMP for Aurora Water. The IWMP integrates short-term and long-range

planning across the Water Resources, Treatment, and T&D disciplines within Aurora Water. It utilizes

consistent key assumptions and the same planning horizon for all disciplines, allowing for the

development of an integrated CIP based on prioritization of all water sector projects using the same

criteria.

The IWMP contains integrated plans for Water Resources, Water Treatment, and T&D, and a

combined10 year CIP. It relies heavily on previous master plans and studies as a basis for planning,

and was developed in close cooperation with Aurora Water staff. The focus of the IWMP is primarily

on growth-related factors that impact the water sector, such as population growth and land

development.

2.2 Overview of the Aurora Water System

The City of Aurora covers an area of approximately 154 sq. mi. and has a population in excess of

340,000 with approximately 122,000 households. Annual growth within the city has historically been

between 1.15% and 1.85% and there are many reasons to suggest that Aurora’s growth rate will remain

strong over time, including:

Large areas of developable land;

Potential for significant job growth; and

Extensive infill and/or re-development opportunities.

Aurora has a semi-arid climate receiving a scant 15-18 inches of precipitation a year. Aurora has four

distinct seasons and precipitation is distributed year-round.

Aurora’s raw water system is designed to provide highly reliable service. Diverse and high quality

sources of water supply are derived from three major river basins: the Colorado, the Arkansas, and

the South Platte. Water from both the Colorado and Arkansas basins is delivered to the South Platte

basin via the Otero Pump Station and Pipeline. Prairie Waters is the newest addition to the water

supply portfolio. It captures reusable return flows from Aurora’s wastewater and lawn irrigation return

flows and returns them to the potable water system after treatment.

Aurora Water maintains three water purification facilities (WPFs): Wemlinger WPF and Griswold

WPF, which treat mountain supplies, and Binney WPF, which treats mountain supplies and Lower

South Platte water from the Prairie Waters system.



The Aurora Water treated water distribution system consists of a network of approximately 1,500

miles of pipelines, eight pump stations, and nine treated water storage tanks to deliver potable water

to residential, commercial,, and industrial customers. Aurora Water maintains a separate non-potable

water system; that system was evaluated during the IWMP process but is not described in this report.

2.3 Authorization

The IWMP was prepared by MWH Americas, Inc. (MWH) under contract 14P0278 dated February

25, 2014. Work was performed in close cooperation with the Aurora Water Planning Department,

technical teams and operations staff for Water Resources, Water Treatment and Transmission &

Distribution.



3.0 Demand Planning

This section summarizes the estimate of future water demands and effectiveness of planned water

conservation measures adopted for the IWMP.

3.1 Water Demands

Results from a new demand forecasting model developed by BBC were used for the IWMP. Aurora

Water’s demand forecasts are based on projections of future growth in the service area, and

projections of the intensity with which Aurora Water’s customers will use water.

The demand forecasting model is a multiple regression model that is based on Aurora Water’s

historical water use characteristics. Factors that affect water use by Aurora’s customers include weather

conditions, conservation efforts, water rates, the presence or absence of watering restrictions, and (for

single family residential customers) the characteristics of new homes and households. The model was

developed with the ability to project water use by month and customer type. The model uses a

traditional deterministic framework to forecast demand in a probabilistic manner that explicitly

quantifies uncertainty surrounding the demand projections.

Table 3-1 shows the estimated demand values for different exceedance percentages, representing the

uncertainty surrounding the future demand projections. For example, there is an estimated 5 percent

probability that demands in 2025 will exceed 63,300 acre-feet per year (ac-ft/yr). In this table, the 90

percent confidence interval around future demands in any of the years is represented by the 5 percent

exceedance level (as the upper bound of the interval) and the 95 percent exceedance level (as the lower

bound). These estimates all assume “average” weather conditions and constant water billing rates

(inflation-adjusted dollars). The estimates also assume a level of water conservation that is consistent

with the 2014 Aurora Water conservation program because that was the effective water conservation

plan at the time of the study. The demand model parameter that has the greatest impact on future

demand estimates is population. Figure 3-1 shows the range of annual demand projections for future

years.



Table 3-1. Annual Demand for Future Years by Exceedance Probability

Exceedance Probability

Total Annual Demand (ac-ft/yr)

2015 2025 2035 2050 2070

5% 51,200 63,300 76,000 96,600 132,400

10% 50,900 62,100 74,600 93,900 127,700

20% 50,300 61,000 72,500 90,700 121,800

50% 49,700 58,900 68,700 84,200 111,000

80% 48,800 56,500 65,100 78,400 100,100

90% 48,400 55,300 63,400 75,100 94,500

95% 48,100 54,400 61,900 72,800 90,100

Note: Demands include 3 percent losses through WPFs and assume 2014 conservation measures.

Note: Demands include 3 percent losses through WPFs and assume 2014 conservation measures.

Figure 3-1. Range of Annual Demand Projections

The water demand estimates from the demand model apply to water from Aurora Water’s WPFs.

These demands were used for the Water Treatment and T&D portions of the IWMP. The Water

Resources portion of the IWMP was based on total raw water system demand at the intakes to the

WPFs. To determine these values, the demand estimates from the demand model were adjusted for

WPF losses. The average water treatment losses were assumed to be 3 percent of the finished water

volumes, based on data provided by Aurora Water. The data presented in Table 3-1 includes this

adjustment and represents the demand that must be met by the raw water system.

0

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Median Upper 90% Lower 90%



3.2 Water Conservation

As part of the IWMP, Aurora Water conducted a review of its water conservation program. The

purpose of the review was to identify additional conservation measures that would be cost-effective

to add to the previous program, and to simultaneously prepare a new Water Conservation Plan for

submittal to the State of Colorado. Water conservation analyses were performed by Maddaus Water

Management, Inc.. The analysis included application of the Maddaus water conservation data and

simulation model to estimate the effectiveness and cost of proposed conservation measures. Results

from the water conservation analysis were incorporated into the IWMP planning scenarios and

demand forecasts.

The water conservation program review identified three possible future conservation programs:

Program A – status quo; continue implementing the water conservation measures included

in the plan implemented by Aurora Water in 2014.

Program B – add additional conservation measures that provide the greatest benefit-cost and

can be readily implemented by Aurora Water.

Program C – add all potentially feasible conservation measures.

Program B was adopted as the basis for Aurora Water’s new Water Conservation Plan and for IWMP

planning. Table 3-2 lists the conservation measures included in Program B.

Table 3-2. Conservation Measures Included in Program B

General Measures Residential Measures

(Indoor)

Commercial Measures

(Indoor) Irrigation Measures (Outdoor)

Real Water Loss

Reduction*

Ultra-High-Efficiency

Toilet (UHET) Only

Rebates*

UHET Only Rebates* Irrigation Audits*

Automated Meter

Infrastructure (AMI)

and Leak Notice

Residential Water

Audits*

High-Efficiency (HE) Urinal

Rebates

Residential Landscape

Conversion*

Water Budget

Based Billing

Multi-Family Water

Audits*

Government Building

Fixtures

Large Property (LP) Landscape

Conversion*

School Education* Leak Repair Assistance*

Top Commercial,

Institutional, and Industrial

(CII) Users

Smart Irrigation Controller Rebate



Table 3-2. Conservation Measures Included in Program B (continued)

General Measures Residential Measures

(Indoor)

Commercial Measures

(Indoor) Irrigation Measures (Outdoor)

Prohibit Water Waste*

Pre-Rinse Spray Nozzles Rain Sensor Rebate

Sprinkler Part Replacement*

Require Rain Sensors*

Water Conserving Landscape

Code*

Soil Amendment Requirement*

Tap Fee Credit*

Z Zones*

*These measures are in Program A and were implemented prior to adoption of the new Water

Conservation Plan.

Table 3-3 shows the percent reduction in per capita water use achieved by Program B as compared

to the 2014 per capita water use over the same period. These reductions in per capita water demand

attributable to conservation Program B were applied to the base water demand forecast for the IWMP

to calculate the water demand used for planning in the IWMP.

Table 3-3. Projected GPCD Change with Conservation Program B as Compared to 2014 GPCD

Year 2014 BBC Median Forecast

without Plumbing Code

2014 BBC Median Forecast

with Plumbing Code

Program B with Plumbing

Code

2014 0% 0% 0%

2015 1% 0% 0%

2020 2% -1% -4%

2025 4% -4% -8%

2030 5% -5% -10%

2040 9% -5% -11%

2050 12% -4% -10%



4.0 Planning Framework

4.1 Planning Horizon

The IWMP addresses water needs and planning strategies from 2016 to 2070. The 2070 date was

established by Aurora Water for consistent planning across all technical disciplines. Planning

milestones were set at 2025, 2035, and 2050 to evaluate interim needs and solutions. Greatest attention

was given to the period from 2016 to 2050.

4.2 Planning Scenarios

The concept of a “planning scenario” was adopted for the IWMP to standardize analyses of uncertain

future conditions over each of the major technical disciplines. Five planning scenarios were developed

by the IWMP team to cover a range of population growth, economic growth, future climate, and

future conservation program assumptions. Two planning scenarios had very similar demands, and

thus were consolidated into one for use by the technical disciplines.

The system-wide water demands and water conservation estimates for the IWMP were used to

calculate the net demands at the WPF intakes, including conservation associated with the four

planning scenarios. All the scenarios assume conservation Program B (i.e., the program being

proposed by Aurora Water in the 2015 Water Conservation Plan).

Two climate conditions were used to develop the hydrology necessary for the IWMP planning

scenarios. The first climate condition assumed no change from recent historical conditions. The

hydrologic ensemble (collection of hydrologic time series with similar statistical properties) associated

with this condition is referred to as the “Paleo” hydrology because it was developed by resequencing

historical streamflows based on the paleo-hydrologic record (i.e., tree ring data). The second climate

condition assumed a hotter, drier future climate. The hydrologic ensemble for this condition was

developed by altering streamflows and water right yields based on results of recent climate change

studies for the Front Range region. This hydrologic dataset, referred to as the “Modified Paleo”

hydrology, has a mean annual ensemble flow about 19 percent lower than the Paleo hydrology.

Table 4-1 shows a summary of the assumptions included in each planning scenario and the associated

system-wide raw water demands including the losses through the WPFs. Demand for finished water

from the WPFs is 3 percent lower than the values in the table. Figure 4-1 is a plot of the estimated

system-wide annual raw water demands for the planning scenarios.



Table 4-1. IWMP Planning Scenario Characteristics

Planning Scenario

Characteristics Hydrology Ensemble

Annual Demands (ac-ft/year) at WPF Intakes

2015* 2025 2035 2050 2070

1) Baseline Plus

Average growth, weather, and hydrology – enhanced conservation (Program B)

Paleo 49,750 55,172 61,313 75,928 95,332

2) Fast Growth

High growth, average weather, and hydrology – enhanced conservation (Program B)

Paleo 51,290 59,438 68,301 87,194 115,811

3) Fast and Hot

High growth, hot/dry weather, and hot/dry hydrology – enhanced conservation (Program B)

Modified Paleo

57,247 66,429 76,477 98,295 130,158

4) Hot Baseline

Average growth, hot/dry weather, and hot/dry hydrology – enhanced conservation (Program B)

Modified Paleo

55,495 61,620 68,550 85,367 106,972

*Forecast was prepared in 2014; actual 2015 demand was 47,540 ac-ft.

Figure 4-1. System-wide Annual Raw Water Demands at WPF Intakes for IWMP Planning Scenarios

Aurora Water executive management determined that Planning Scenario 2 (Fast Growth) would be

used as the basis for IWMP CIP development.

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4.3 Risk Identification

For the purposes of this risk program, “risk” refers to the threats that can potentially impact Aurora

Water’s water supply requirements. A Risk Management Framework (RMF) was developed as one of

the foundational elements of the IWMP and guided the risk identification, evaluation and analysis of

risks in the water supply system for Aurora Water. The risk identification and assessment approach

included four risk workshops covering Source of Supply (i.e., watersheds that are sources of Aurora

Water raw water supply), Raw Water Infrastructure (i.e., infrastructure associated with the collection,

storage and delivery of raw water), Treatment, and T&D. Risk workshops were carefully designed to

ensure the RMF was followed, and at the same time generating appropriate information through active

participant engagement.

The process for conducting each workshop is shown in Figure 4-2, and includes the pre- and post-

workshop activities.

Figure 4-2. Risk Workshop Process

Workshop participants focused on identifying CIP growth-related mitigation strategies consistent with

the requirements of the IWMP; however, mitigations associated with ‘routine’ asset management and

operations also were identified. While not always directly applicable to the development of the IWMP,

identification and discussion of asset management and operational mitigation strategies proved

valuable for Aurora Water as it now has a greater understanding of how to manage water supply, raw

water infrastructure, treatment, and T&D risks associated with its water supply.



In total, 88 risks were identified across all the system components during the workshops. Risk ratings

were assigned by workshop participants based on a combination of consequence and likelihood. Of

the 88 risks identified, 10 where ultimately determined as being CIP or climate related and these are

shown in Table 4-2. These IWMP-specific risks and potential mitigations were captured and

summarized separately in the discipline-specific technical memoranda (TM).

Table 4-2. CIP Growth and Climate Related Risks

CIP Growth and Climate Related Risks

Contamination of surface water in the Upper South Platte basin, from ash/sediment, and debris flow, following wildfire and flood

Contamination of surface water in the Upper Arkansas basin, from ash/sediment, and debris flow, following wildfire and flood

Contamination of surface water in the Upper Colorado basin, from ash/sediment, and debris flow, following wildfire and flood

Change in average annual stream flow, and a shift in earlier peak runoff timing due to hotter, drier climates

Multi-year drought leads to future low stream flows, beyond that seen in the historical record

Curtailment in Colorado River transbasin deliveries due to regulatory measures to compact obligations

Failure of raw water pipelines (with the potential that both Rampart pipelines fail in one location

Loss of North Campus pump stations and North Campus conveyance

Inability to meet rated design capacity for Griswold WTF

Inadequate water flow and/or pressure through the water system

4.4 IWMP Assumptions

Numerous assumptions were required to complete the analyses associated with the IWMP. The

IWMP project team maintained an assumptions log to track assumptions and present them to Aurora

Water for consideration.



5.0 Water Resources

5.1 Introduction

This section presents the results of Aurora Water’s water resources planning efforts conducted as part

of the IWMP. The water resources plan presents an adaptive management strategy for addressing

future water supply needs under alternative growth and climate scenarios for both short-term needs

and long-term (2070) conditions.

The water resources analysis of the IWMP addresses Aurora Water’s raw water supply and

infrastructure system, including water rights, collection facilities, storage reservoirs, and conveyance

facilities “upstream” of Aurora Water’s water purification facilities (WPFs). This report presents a

roadmap for Aurora Water’s future water resources development, with a detailed near-term strategy

and a robust long-term plan that will help Aurora Water to continue providing water reliably to its

growing customer base in a cost-effective manner.

5.2 Basis of Planning

The basis of planning for the water resources portion of the IWMP was described in Sections 3 and

4. In addition, the water resources plan was based on hydrologic data representing potential future

conditions. Simulations of Aurora Water’s water supply system were performed using a Paleo

hydrologic ensemble representing current climate conditions and a Modified Paleo hydrologic

ensemble representing a hotter, drier climate that would result in an approximate 19 percent reduction

in mean streamflow. Each of these ensembles contains 50 different 61-year sequences of hydrology,

representing a variety of drought patterns that could be realized in the future.

5.3 Water Resources Modeling

The Aurora Water supply simulation model (Excel-CRAM) was used to quantify impacts of water

resource risks on raw water system performance. It simulated operation of physically and legally

available flows to meet Aurora’s water demand and other obligations. The IWMP water resources

team developed a data-centered decision support framework integrating the existing Excel-CRAM

model, a Structured Query Language (SQL) database, and a custom data management system (DMS)

that processed and imported data, setup system conditions/scenarios, ran simulations, and calculated

metrics to evaluate system performance under different conditions and solution portfolios for Aurora

Water. Through the DMS interface options and supporting database, the Excel-CRAM model was

dynamically altered to simulate the various future conditions and build portfolios of projects to address

those conditions.



Baseline models were used as the starting point of the water resources analysis and were developed

for existing (2015) and future (2070) conditions. The baseline models include currently owned water

rights and current operation of Aurora Water facilities, historical operation of other entities in the

source basins, and all existing water projects (e.g., reservoirs and storage accounts).

Aurora Water’s drought response program was included in the Baseline Excel-CRAM model used for

the IWMP. This drought response program reduces water demand during years of limited supply or

other emergencies that would reduce effective supply available to the system (e.g., conveyance system

outages). Drought response triggers are tied to system-wide reservoir storage amounts. Three stages

are defined by Aurora Water’s drought response program, as shown in Table 5-1. The amount of

demand reduction for each stage was based on the assumed effectiveness of outdoor watering

restrictions, as provided by Aurora Water. System conditions required to activate the various drought

response stages are defined in Table 5-2.

Table 5-1. Drought Response Stages and Watering Restrictions

Drought Response Stage Watering Restriction(1) Assumed Demand to be Met

Normal Voluntary non-fixed 3-day watering 100% Indoor + 100% Outdoor

Stage I – Severely Dry Mandatory fixed 2-day watering 100% Indoor + 80% Outdoor

Stage II – Exceptionally Dry Mandatory fixed 1-day watering 100% Indoor + 50% Outdoor

Stage III – Emergency Conditions No outdoor watering 100% Indoor only

Table 5-2. Drought Response Stage Thresholds for Current Demand and Storage Conditions

Characteristic Normal Stage I –

Severely Dry

Stage II –

Exceptionally

Dry

Stage III –

Emergency

Conditions

Reservoir System Storage (ac-ft) (1) 156,219 – 95,000 95,000 62,000 24,000

Percentage of Total Reservoir System

Storage 100% -- 59% 59% 39% 15%

Drought Stage Threshold as a Factor of the

Annual Demand (2) 3.09 – 1.88 1.88 1.23 0.48

(1) Reservoir system storage triggers for drought response will increase as annual demand increases. (2) Calculated based on annual demand of 50,500 ac-ft/yr; exceeds 2015 annual demand of 47,540 ac-ft/yr.

To evaluate water resources system performance for the IWMP, Aurora Water adopted metrics that

capture and summarize key behaviors of the water resources system modeled in the Excel-CRAM

model. Multiple frequency-based metrics were necessary to describe system performance under

conditions of future uncertainty. Metrics measured reliability (shortage frequency – how often?),

resiliency (shortage duration – how long?), and vulnerability (shortage magnitude – how severe?).

Three metrics were selected to replace firm yield2 as the basis for water supply planning. Acceptable

1 Assumed regulation to achieve the outdoor demand goal. 2 Aurora Water defines firm yield as the demand that can be met each and every year at the WPFs under historic supply

conditions without allowing total reservoir contents to go below an operating reserve equivalent to 1 year of residential

demands computed using a rate of 135 GPCD.



thresholds, or LOS goals, were established by Aurora Water for each metric. Metric definitions and

LOS goals are summarized in Table 5-3.

Table 5-3. Key Metrics for Water Resources System Performance Analysis

Metric Name Description Target Acceptable

LOS (1) LOS Narrative

No-Restriction

Frequency

Probability of being in

“Normal Conditions” above

the Stage I threshold storage

level at the beginning of any

May

Stage I storage

level >0.80 (80%)

There will be no additional

outdoor watering restrictions (2) in a minimum of 8 years

in 10; or, there will be some

form of drought restrictions

no more than 2 years in 10

Reduced

Supply

Reliability

Probability of meeting

reduced customer demands

with drought response

watering restrictions on a

monthly basis

Demands after

reductions from

drought

restrictions have

been applied

=1.0 (100%)

Will always meet demands

that are reduced due to any

level of drought restrictions

WISE (3)

Supply

Reliability

Probability of meeting WISE

obligations on a monthly

basis

10,000 ac-ft

annual demand = 1.0 (100%)

Will always meet WISE

supply obligations

(1) Metrics range from 0 to 1.0, where 1.0 indicates the best possible performance and 0 represents the worst possible

performance. Acceptable performance is greater than the acceptable LOS. (2) No additional restrictions beyond the three day per week voluntary watering restrictions that are permanently in

place under “Normal Drought Stage” conditions. (3) Water Infrastructure and Supply Efficiency (WISE) Partnership.

5.4 Vulnerability and Planning Scenarios Assessment

The vulnerability assessment defined the future conditions under which Aurora Water’s current

system is unable to maintain the LOS goals for the metrics defined above. This analysis was conducted

in two phases:

1) Vulnerability Assessment – Identify and quantify the effects of the key external factors that

could lead to water resources system performance problems now and in the future.

2) Planning Scenarios Assessment – Identify years and levels of demand for which actions

would be required to maintain the desired LOS with Aurora Water’s defined acceptability

thresholds for each planning scenario.

The vulnerability assessment tested the current water resources system’s ability to respond to (a)

changes in demand and/or hydrology and (b) the application of risks to the water supply sources and

water resources infrastructure. The key findings of the vulnerability assessment are summarized below.

Demands could be increased from the current demand of 47,540 ac-ft/year up to 56,000 ac-ft/year and the existing system could still meet the LOS goals for the performance metrics if historical hydrology were to repeat. This demand level of 56,000 ac-ft/year would occur



around 2025 for Planning Scenario 1 (Baseline Plus), 2022 for Planning Scenario 2 (Fast Growth), and 20153 for Planning Scenarios 3 (Fast and Hot) and 4 (Hot Baseline).

Hydrologic variability without impacts of climate change would result in hydrologic conditions (droughts) for which LOS goals cannot be met by 2025 similar to under historical hydrology.

Climate change of the magnitude depicted by the Modified Paleo hydrologic ensemble (about 19 percent reduction in mean streamflow) would significantly affect the ability of the current system to meet LOS goals by 2025.

Eleven system risks were investigated with the Excel-CRAM model under current and future demands. The risk posing the largest relative loss of performance (i.e., greatest threat) is loss of Colorado River Basin imports over a consecutive five-year period due to a Colorado River Compact curtailment.

The current drought response program effectively mitigates the long-term effects of individual

dry years, allowing the current system to maintain acceptable performance for a total system

demand of about 8,500 ac-ft/year higher than if the drought response program were not in

place.

After the vulnerability assessment, an assessment was performed to further define the future water

needs and evaluate performance of the existing water resources system. For this assessment, the

Baseline Excel-CRAM model (existing infrastructure and water rights) was run under three of the four

IWMP planning scenarios (excluding Planning Scenario 3 [Fast and Hot]). Drought response measures

were included in all simulations. Water needs were evaluated first for future conditions without

occurrence of any system risks, and then for future conditions with the key system risks identified in

the vulnerability assessment.

Results of the planning scenarios assessment are summarized in Figure 5-1. Values in the figure

correspond to the Non-Restriction Frequency under baseline conditions for the three planning

scenarios at multiple future years with and without key system risks applied. With no system risks, the

existing system will fail to meet the acceptable LOS between 2015 and 2025. The loss of Colorado

River supplies for five consecutive years is the most impactful risk. Other system risks have minimal

negative impact on the system.

It was concluded that Aurora Water’s current system will be unable to meet LOS goals by around

2025 if no system risks occur. If system risks are applied in the analysis, Aurora Water’s current system

will be unable to meet LOS goals in earlier years. Because of the uncertainty surrounding many of

these risks, it is important they be considered when developing the near-term water supply planning

strategy.

3 Actual 2015 demand was significantly less than forecasted 2015 demand for IWMP planning.



Note: Acceptable LOS for Non-Restriction Frequency metric is 80 percent.

Figure 5-1. Non-Restriction Frequency System Performance with Selected System Risks

5.5 Water Resources Projects

Aurora Water and the MWH team developed a list of projects that would be used to construct water

resources portfolios. A long-list of potential projects, programs, and policies was prepared, and

infeasible or undesirable projects were removed by Aurora Water. Nineteen potential water resources

supply projects (reservoir storage, gravel lakes, water rights acquisitions, and agricultural water leases)

and seven delivery system improvement projects were retained for consideration in building water

resources portfolios. These are listed in Table 5-4 and Table 5-5.



Table 5-4. Potential Water Resources Supply Projects for Analysis in the IWMP

No. Project/ Program Source Project Size Earliest Year of

Implementation

Description

Arkansas/Colorado Potential Projects List

1 Eagle River

Memorandum of

Understanding

(MOU) Project

(IPP4)

Gerry Knapp Primary goal of the

ERMOU is 10,000 ac-ft

of yield to Aurora.

2035

The Eagle River MOU Project would be Aurora’s portion of a

multi-party project consisting of Aurora, Colorado Springs

Utilities and west slope partners. Studies by the partners are

ongoing to determine the most feasible project alternatives to

meet the needs of the partners.

2 Box Creek

Reservoir (IPP)

Gerry Knapp Multiple different size configurations are

feasible. Up to 25,000 ac-ft by gravity and up

to 60,000 ac-ft by pumping.

2030 Box Creek Reservoir site is located primarily on City owned

property in Lake County near Twin Lakes. This project would

provide operational flexibility and efficiencies to Aurora ’s water

supply system.

The project could receive all of Aurora’s Colorado and

Arkansas Basin water. For the existing topography, water could

be released by gravity.

Aurora has an agreement with Lake County. Twenty percent of

capacity is held as a minimum pool, accessible only during

drought periods. Twenty percent of the remaining operational

storage space goes to Lake County for its use.

3 Arkansas Basin

Agriculture (Ag)

Leasing

Gerry Knapp 10,000 ac-ft/year in

years lease is executed

(3 in 10)

2020 The objective of intermittent leasing would be to develop a

contractual arrangement between the City and willing

agricultural water lessees The City would obtain the right to

lease water from multiple farms for up to 3 years in each 10

year period.

Project size would be targeted at 10,000 ac-ft of yield per year

when needed. An estimated 7,200 acres of leased irrigated

land would be needed to reach the target of 10,000 ac-ft.

4 Identified Projects and Processes





Implementation

Description

4 Post 2047 Ag

Purchase

Gerry Knapp 10,000 ac-ft/year 2047 Current agreements restrict Aurora from purchasing and

permanently transferring additional Arkansas River Basin water

supplies between 2007 and 2047. However, following 2047

potential exists to develop additional agricultural water supplies.

Such purchases may depend upon the successes and reliability

of Alternative Transfer Methods.

6 Trans-Basin

Water Rights

Gerry Knapp 2,500-6,500 ac-ft/year

as annual base supply

2025 Potential purchase of Colorado River supplies could include

acquisition of shares in trans-basin systems should they

become available.

7 Gravel Pit and

Recovery of Yield

(ROY) Storage

Development

Gerry Knapp 5,000-10,000 ac-ft of

storage space for

Aurora

2020 ROY storage would capture flows bypassed by Aurora and

allowed to flow through Pueblo under the 6-Party Regional IGA

to which Aurora is a party. ROY storage is anticipated to

provide approximately 5,000 ac-ft of storage space, which could

be increased to 10,000 ac-ft of storage space when combined

with other gravel pit storage to be developed.

9 Extension of

Pueblo Board of

Water Works

(BOWW) Lease

Gerry Knapp 5,000 ac-ft/year

annually, taken every

year

2025 The City could extend or replace its current lease for 5,000 ac-

ft/year of water beyond the current contract expiration date of

2024.

12 Expanded Otero

Conveyance

Gerry Knapp 150 million gallons per

day (MGD) total

capacity, 75 MGD

capacity for Aurora

(50% increase over

existing capacity)

2040 This project involves a partnership with Colorado Springs to

expand capacity of the existing Homestake Pipeline, which

would result in a 50 percent increase in capacity.

14 Pueblo Reservoir

Enlargement

Gerry Knapp Total enlargement

considered was

75,000 ac-ft Analyze up

to 10,000 ac-ft for

Aurora Water

2040 There could be a potential opportunity for Aurora to expand its

storage in Pueblo Reservoir in the event Pueblo Reservoir is

enlarged. This would be a Bureau of Reclamation project and

would have other partners as well. For the IWMP, this is

assumed to be Long-Term Excess Capacity space. In any case

Aurora would seek about 10,000 ac-ft of additional space.





Implementation

Description

15 Mountain Storage

– Upper South

Platte (IPP)

2012 CIP

Memo

32,000 ac-ft storage

reservoir

2020 This project includes construction of a 32,000 ac-ft reservoir in

Park County approximately 6 miles upstream from the Spinney

Mountain Reservoir. Homestake Pipeline deliveries could be

made to Mountain Storage – Upper South Platte, minimizing

the potential for spilling Aurora Water’s Upper Arkansas and

Colorado River supplies. This project is also known as

Wildhorse Reservoir.

16 Terminal

Reservoir (IPP)

2012 CIP

Memo

60,000 ac-ft 2030 Terminal Reservoir (or potentially East Reservoir) would be

constructed to provide up to 60,000 ac-ft of terminal storage.

Aurora may not need the full storage volume and could contract

out excess capacity. Terminal Reservoir would be filled with

Prairie Waters System water and available mountain blend

water. The project would include reservoir construction (dam

embankment, outlet works, spillway, and spillway channel), and

water delivery (Prairie Waters Pump Station 3 modifications

and pipeline to the Binney Water Purification Facility [WPF]).

17 Lower South

Platte Storage”

Lisa Darling Up to 10,000 ac-ft of

storage

2040 Lower South Platte storage would be developed on an

appropriate timeline for incorporation into the lower South

Platte system. Operation will be the same as Everist Gravel Pit,

and it could be modelled as an enlargement of Everist Gravel

Pit.

South Platte Gravel Pits – Existing Contracts

18 Lake Clare

Gravel Pit

Storage:

Based on

Aurora Water

Storage

Reservoir List

document

4,050 ac-ft 2030 Lake Clare Gravel Pit storage would provide operational

storage for Prairie Waters System. The 2012 CIP indicated that

storage of 4,050 ac-ft would be available at Lake Clare.

Projects 18, 19, and 20 are simulated as one project.





Implementation

Description

19 Challenger

Gravel Pit

Storage:

Based on AW

Storage

Reservoir List

document

775 ac-ft 2016 Challenger Gravel Pit storage would provide operational

storage, and is located between the Kirby-Dersham Gravel Pit

to the north and Lake Clare to the south. The 2012 CIP

indicated that storage of 775 ac-ft would be available at

Challenger Gravel Pit. The only infrastructure associated with

Challenger Gravel Pit is an interconnection with Kirby-Dersham

Gravel Pit.


20 Kirby-Dersham

Gravel Pit

Storage:

Based on

Aurora Water

Storage

Reservoir List

document

1,056 ac-ft 2016 Aurora would pay Hall-Irwin for operational storage in Kirby-

Dersham Gravel Pit, and would design/build a pump station for

the site. The site could be connected to Walker Reservoir

Gravel Pit. Budget for Kirby-Dersham Gravel Pit also includes a

connection to the Challenger Gravel Pit. The 2012 CIP

indicated that storage of 1,056 ac-ft would be available at Kirby-

Dersham Gravel Pit.


21 Everist Gravel Pit Storage:

Based on

Aurora Water

Storage

Reservoir List

document

Phase I – 2,556 ac-ft

Phase II – 2,836 ac-ft

Phase III – 6,089 ac-ft

Total – 11,481 ac-ft

Phase I – 2015

Phase II – 2019

Phase III – 2034

The Everist Gravel Pit storage project includes paying L.G.

Everist for the storage and existing infrastructure. The Everist

Gravel Pit would be developed in three phases: Phase I (2,556

ac-ft), Phase II (2,836 ac-ft), and Phase III (6,089 ac-ft). Total

cumulative storage would be 11,481 ac-ft Everist Gravel Pit

would serve as an augmentation storage reservoir for Prairie

Waters.

Projects 21 and 22 are simulated as one project.

22 Walker Reservoir

Gravel Pit

Storage:

Based on AW

Storage

Reservoir List

document

3,300 ac-ft 2016 Aurora would construct a pump station and other improvements

to the existing Walker Pit complex. The 2012 CIP indicated that

storage of 3,300 ac-ft would be available at Walker Pit. This

would be operated as augmentation storage.

Projects 21 and 22 are simulated as one project.





Implementation

Description

24 Water Rights

Acquisitions

Deere and

Ault

Up to 20% increase in

Lower South Platte

water rights (average of

approximately 9,000 ac-

ft per year)

2016 Aurora may acquire and change existing Lower South Platte

agricultural water rights to include municipal use. Water would

be stored in the gravel pit reservoirs described previously, and

then moved through Prairie Waters System to the city. The

yield of the water rights would vary by the associated ditch

company and water right.

25 Denver Basin

Groundwater

Aurora Water

staff

Additional supply of up

to 15,000 ac-ft/year in

dry years (3 of 10)

2025 New Denver Basin groundwater wells could be used as a base

source of supply or just for emergency reserves. The total

adjudicated Denver Basin withdrawal rate for Aurora is 45,000

ac-ft/yr. For the IWMP the total new yield from Denver Basin

groundwater in this project would be up to 15,000 ac-ft/year,

and would be used as a dry-year supply (i.e., 3 years out of 10

years). It was assumed that wells would be screened in the

Arapahoe formation, with an assumed well pumping rate of 300

gallons per minute (GPM). Approximately 6 wells would be

required for a total potential yield of 1,600 ac-ft/year. This can

be scaled up for higher yields.



Table 5-5. Potential Delivery System Improvement Projects for Analysis in the IWMP

No. Project/

Program

Source Project Size Earliest Year of

Implementation

Description

1 Wemlinger

Blended Water

Pipeline

2012 CIP Memo 33 MGD 2019 (based on

current CIP

schedule)

New 60-inch diameter pipeline would be installed along Quincy

Avenue to supply up to 80 MGD of Aurora Reservoir water by gravity

to Wemlinger WPF. This project would allow the simultaneous filling

and drawing of Aurora Reservoir water, provide needed operational

flexibility to maintain Aurora Reservoir levels needed for Binney WTP

operations, and would minimize water quality issues in Aurora

Reservoir. As was assumed for the 2012 Water Treatment Master

Plan (WTMP), this project does not include upgrades to the

Wemlinger WPF.

Prairie Waters System Pipeline Expansion Related Projects

2c Prairie Waters

North Campus

Expansion to

20 MGD

2012 CIP Memo Total 20 MGD 2019 based on 4

years for design,

construction and

procurement

This project includes future well field development for the PW North

Campus Expansion. The expansion would increase the total firm

capacity for PW to 20 MGD from an existing firm capacity of 8.5 MGD.

Key project components would include acquisition of properties for the

East Wellfield, installation of seven new wells in the existing wellfield,

25 new riverbank filtration (RBF) wells (seven in Phase 1 and an

additional 18 in Phase 2) and pipelines to develop the new East

Wellfield, and a river crossing to connect the wellfields.

2d Prairie Waters

North Campus

Expansion to

30 MGD


years for design,

construction and

procurement


Campus Expansion. Total capacity for PW would increase from a firm

capacity of 20 MDG to 30 MGD. This expansion assumes that RBF

capacity would be increased to 20 MGD prior to this project. Key

project components would include land acquisition for proposed RBF,

construction of a 10 MGD RBF wellfield and connecting pipelines, and

an increase of PW conveyance pumping capacity to 45 MGD.

2e Prairie Waters

North Campus

Expansion to

40 MGD


years for design,

construction and

procurement


Campus Expansion. Total capacity for the PW would increase from a

firm capacity of 30 MGD to 40 MGD. Key project components would

include land acquisition for proposed RBF, construction of a 10 MGD

RBF wellfield and connecting pipelines (total RBF capacity of 40

MGD), and build out of the PW conveyance pumping to the design

capacity of 50 MGD.



Table 5-5. Potential Delivery System Improvement Projects for Analysis in the IWMP

No. Project/

Program

Source Project Size Earliest Year of

Implementation

Description

Rampart Delivery System and Aurora Reservoir Expansion and Improvement Projects

3 Holly Street

Pump Station

Expansion

WTMP-

CH2MHILL,

2012

Expand to 90 MGD n/a Expansion of the decommissioned Holly Street Pump Station to 90

MGD capacity would provide capacity for increased deliveries from

Rampart Reservoir. Based on information from a workshop conducted

as part of the 2004 Rampart Delivery System Alternatives Evaluation,

the nearly 13,000 linear feet of 54-inch pre-stressed concrete cylinder

pipe that is in poor condition would be replaced with ductile iron pipe.

4 New Rampart

Supply Pipeline

WTMP-

CH2MHILL,

2012

45 MGD increase

Total 125 MGD capacity

n/a A new parallel Rampart Delivery System Pipeline would increase the

Mountain Water System flow rate to the Griswold WPF and

Wemlinger WPF. The project would include a new 72-inch diameter

pipeline that would parallel the existing Rampart Delivery System

pipelines from Rampart Reservoir to State Highway 470, a new 66-

inch diameter pipe from C470 to Quincy Avenue, and new 60-inch

pipe from Quincy to the Griswold and Wemlinger WPFs.

5 Aurora

Reservoir Pump

Station

Expansion

WTMP-

CH2MHILL,

2012

30 MGD expansion

Total 70 MGD capacity

n/a Modifications to the existing Aurora Reservoir Pump Station at the

Quincy Reservoir site to a capacity beyond the current 40 MGD may

allow Aurora Water to capture more mountain water by not spilling at

Strontia Springs Reservoir. The project would include the addition of

four 800 horsepower pumps, the replacement of the existing low flow

pump, new motors and variable frequency drives, and electrical

modifications. The objective would be to increase to a 70 MGD

capacity.



A feasibility engineering assessment and associated cost estimate were prepared for each water resources

project. For most projects, previous cost estimates were used and updated as needed. The following types of

cost were included in the water resources project cost estimates:

Capital construction

Permitting

Engineering

Construction management

Contingency

Land acquisition

Operation and maintenance (O&M)

Energy use

All cost estimates are in 2015 dollars with no adjustment for inflation to a projected construction date.

O&M costs were estimated as a percentage of capital cost, unless more specific information was available.

Energy costs for projects with significant pumping components were also estimated. All annual costs (O&M,

energy, and leasing) were converted to 2015 present worth values using a specified project life. Present worth

values of 50 years of recurring annual costs were added to capital costs to estimate a total project cost.

Cost estimates for water resources supply projects are shown in Table 5-6 and cost estimates for water

resources delivery projects are shown in Table 5-7.



Table 5-6. Cost Estimates for Potential Water Resources Supply Projects

Project/ Program Project Size

(ac-ft or ac-ft/year) Capital Cost Permitting Design Contingency

Construction

Management

Land

Acquisition

O&M Present

Worth (PP) (1)

Energy Costs Present

Worth (PP) (2) Total Project Costs

Water Storage 283,260 $1,218,286,000 $45,500,000 $45,482,000 $267,172,000 $29,207,660 $9,050,000 $268,600,800 $4,179,000 $1,883,927,000

Water Supply Acquisition 23,000 $34,9620,000 $4,884,900 0 $104,886,000 0 0 $0 0 $459,405,000

Water Leasing 7,330 $18,000,000 $180,000 0 $17,630,000 0 0 $49,962,000 0 $85,770,000

Ground Water 1,600 $6,019,000 - $301,000 $1,806,000 $60,190 - $150,200 $444,500 $8,781,000

(1) Present worth based on 50 years of operation and an interest rate of 7.8 percent. (2) Some totals may differ from sum of individual cost elements due to rounding.

Table 5-7. Cost Estimates for Potential Delivery System Improvement Projects

Project/ Program Estimated Project

Size (MGD) Capital Cost Permitting Design Contingency

Construction

Management

Land

Acquisition

O&M Present

Worth (PP) (1)

Energy Costs Present

Worth (PP) (2) Total Project Costs

New or Expanded Conveyance System to South Platte (Otero II) 25 $74,320,000 $2,230,000 $4,459,000 $22,300,000 $4,459,000 - $26,990,000 $23,550,000 $215,500,000

Wemlinger Blended Water Pipeline 33 $54,950,000 $1,099,000 - - $2,748,000 - $14,720,000 - $73,520,000

PW North Campus Expansion to 20 MGD, PW PS to 20 MGD 10 $14,730,000 $441,900 $736,500 $4,419,000 $736,500 - $5,275,000 $11,490,000 $37,830,000

PW North Campus Expansion to 30 MGD, PW PS to 45 MGD 10 $12,320,000 $369,600 $616,100 $3,696,000 $616,100 $2,805,000 $4,412,000 $11,490,000 $36,330,000

PW North Campus Expansion to 40 MGD; PW PS to 50 MGD 10 $12,320,000 $369,600 $616,100 $3,696,000 $616,100 $2,805,000 $3,309,000 $11,490,000 $35,220,000

Holly Street Pump Station Expansion 27 $12,290,000 - $614,400 $3,687,000 $614,400 - $2,154,000 $9,503,000 $28,860,000

New Rampart Supply Pipeline 52 $195,900,000 $3,918,000 $15,670,000 $19,590,000 $9,794,000 - $45,980,000 $8,266,000 $299,100,000

Aurora Reservoir Pump Station Expansion 30 $6,800,000 - $680,000 $2,040,000 $340,000 - $1,235,000 $10,300,000 $21,400,000

(1) Present worth based on 50 years of operation and an interest rate of 7.8 percent. (2) Some totals may differ from sum of individual cost elements due to rounding. (3) Costs for several projects were updated during the CIP prioritization phase of the IWMP. Costs in this table were used to select projects for water resources portfolios.



5.6 Water Resources Portfolios

With Aurora Water’s vulnerabilities and needs identified, the final step was to develop solutions that

ensure Aurora Water meets the LOS goals for future conditions. To develop these solutions, Aurora

Water assembled portfolios (i.e., collections of individual projects) that meet future water needs under

different planning scenarios and at different future dates. The following assumptions were applied to

the development of water resources portfolios:

The performance of candidate portfolios was measured using the three key system

performance metrics selected for the IWMP: Non-Restriction Frequency, Reduced Supply

Reliability, and WISE Reliability (Table 5-3).

Portfolios were developed for IWMP Planning Scenario 1 (Baseline Plus), Planning Scenario

2 (Fast Growth), and Planning Scenario 4 (Hot Baseline). These three planning scenarios were

applied at four future dates (2025, 2035, 2050, and 2070), resulting in a total of 12 future

conditions. Note that it was determined previously by Aurora Water that Planning Scenario 3

(Fast and Hot) would not be used for IWMP planning due to conditions within that scenario

that were considered more severe than necessary for creating a reasonable CIP for the IWMP

(i.e., it fell outside the 90 percent confidence limits of forecasts from the demand regression

model); this scenario could be explored in future iterations of the IWMP.

All portfolios include Base Projects that (1) Aurora Water has already committed to

implement, (2) Aurora Water has executed contracts or agreements to complete, or (3) were

considered time sensitive.

The portfolio development process is summarized in Figure 5-2. This process used a multi-objective

evolutionary algorithm to perform optimization-based searches (OPT-Search) of thousands of

portfolios, developing a tradeoff between performance and cost. These selected portfolios where then

run through a hydrologic robustness analysis to evaluate performance over a greater variety of future

hydrologic conditions, ensuring the robustness of selected portfolios. These portfolios were then

offered as the water resources contribution to the CIP.

Figure 5-2. Overview of Portfolio Development Process

Figure 5-3 summarizes the portfolios selected for the CIP across three planning scenarios and four

planning years. The green, blue, orange, or yellow color indicates that the project is needed by the

corresponding future year (2025, 2035, 2050, and 2070, respectively). The gray color indicates that the

All

Projects

Analysis

OPT-

Search

Sensitivity

Analysis

Hydro

Robust

Analysis

CIP

Portfolios



project is included in the portfolio but would have been completed at an earlier planning year. The

white color indicates the project is not required for that planning scenario and year.

Figure 5-3. Summary of CIP Portfolios for Each Planning Future

The Wemlinger Blended Water Pipeline is shown as coming online in 2035 due to input from Aurora

Water related to its operational benefits; for water supply purposes it could be delayed until later years.

It was not possible to assemble portfolios from all the available projects to meet the LOS goals in

2070 for Planning Scenarios 2 (Fast Growth) and 4 (Hot Baseline). A supplemental optimization

analysis was performed using conceptual, non-specific types of projects to determine how the 2070

Gap could be filled. Table 5-8 shows the results of this analysis. A project concept was developed

called the Lower South Platte Advanced Treatment Project, which would provide treatment of Lower



South Platte water such that the current requirement for blending with mountain supplies to meet

Total Dissolved Solids (TDS) objectives would be significantly reduced. This concept was found to

be highly effective in 2070. 2070 portfolios are shown with and without this project due to uncertainty

over its technical and economic feasibility. These results assume the same acceptable levels of service

adopted for all other planning years. A reduction in the acceptable LOS could be investigated in a

future analysis.

Table 5-8. Balanced Storage/Supply Portfolios for 2070 Gap

Lower South Platte

Advanced Treatment Gap Project Size

Off

South Platte Storage 15,000 ac-ft

Arkansas Water Rights 15,000 ac-ft

Colorado River Water Rights 3,000 ac-ft/year

Denver Basin Groundwater 12,000 ac-ft

Prairie Waters System Additional Capacity 10 MGD

Off

Arkansas Storage 15,000 ac-ft

Terminal Storage 10,000 ac-ft


Arkansas Water Rights 15,000 ac-ft

Denver Basin Groundwater 6,000 ac-ft

On

South Platte Storage 10,000 ac-ft


Arkansas Water Rights 3,500 ac-ft/year

Arkansas Storage 15,000 ac-ft

On

Terminal Reservoir 10,000 ac-ft


Arkansas Water Rights 500 ac-ft/year

Colorado River Water Rights 500 ac-ft/year

NOTES:

(1) Portfolios include specific water resources projects identified by Aurora Water. (2) Project sizes are in addition to the sizes of similar projects included in the CIP portfolios. (3) Million gallons per day (MGD).

5.7 Water Resources Plan

Aurora Water is adopting strategies to implement the water resources recommendations in the IWMP.

These strategies are based on the need to position the organization to meet its customer water needs

in a growing region with an uncertain future climate, aging infrastructure, and increasing competition

for scarce water supplies. Strategies for water resources planning are shown in Figure 5-4.

A 10 year CIP was prepared for the IWMP that included water resources projects that must be

completed between 2017 and 2026. This is described in Section 8.



Figure 5-4. Aurora Water Resources Strategies and Threats

Aurora Water management determined the IWMP should focus on growth-related capital project

needs, which is the focus of the 10 year CIP. Appropriate long-term water resources planning also

must consider the need to address risks to current and future infrastructure and operations that could

jeopardize the ability of the utility to meet its LOS goals.

The water resources vulnerability analysis shows that the Aurora Water system is vulnerable to the

risk of losing 100 percent of Colorado River yields in five consecutive years (which could happen

under a Colorado River Compact curtailment situation), a two-year Otero pipeline or pump station

outage, or a one-year Rampart Pipeline/Strontia Reservoir outage. If these events occur, Aurora Water

may not be able to meet its indoor demands at all times without going to City Council to impose

emergency restrictions more frequently than is considered acceptable (Stage 1 no more than 20 years

in 100, Stage 2 no more than 5 years in 100, and Stage 3 no more than 1 year in 100).

Aurora Water’s two primary strategies for addressing key risks and vulnerabilities are diversification

and redundancy. Aurora Water is well positioned to deal with many risks to its raw water infrastructure

system because of its proactive approach in the past to developing a diversified water portfolio. This

strategy of diversification will be continued in the future, but will be more challenging to achieve due

to constraints on additional Arkansas River Basin water development for Aurora Water and challenges

to Colorado River Basin water development in general for all Front Range entities.

Aging raw water infrastructure will be a growing concern for Aurora Water over time. Additional

investment will be needed in O&M, repair, and replacement as more facilities approach their useful

life. Aurora Water plans to develop an Asset Management Plan when the IWMP is completed to

develop an appropriate strategy for asset management and maintenance.



During the process of preparing the IWMP, Aurora Water identified a need to conduct follow-up

studies to refine previous analyses or further investigation for possible water supply options. Possible

follow-up studies include the following:

Feasibility of expanded potable reuse through additional Prairie Waters System treatment

Denver Basin groundwater assessment

WISE modeling improvement

Emergency storage analysis

Drought storage level analysis

Enhanced conservation program options

Level of service changes

Aquifer Storage and Recovery options

Additional climate altered hydrology studies

The strategy of continuous planning and adaptation requires that Aurora Water constantly monitor

growth in its service area, water demand, climate variability, and regulations and legislative initiatives

that could affect the ability to manage water and implement projects (see Figure 5-5). Aurora Water

must be committed to diligently tracking these factors with other Front Range water providers and

adjusting its planning decisions accordingly.

Figure 5-5. Factors to Track for Adaptive Water Supply Planning



6.0 Treatment

6.1 System Design Requirements

This section summarizes the recommended water purification facility improvements based on the

2012 Treated Water Master Plan (TWMP) (CH2M Hill, 2012) and the 2015 Aurora Water Treatment

Capacity Capital Improvements Plan Review and Update (CIP Update) (CH2M Hill, 2015), as well as the

demand scenarios described previously. The recommended improvements have been evaluated based

on meeting projected demands and do not take into account projects that are necessary in order to

maintain or extend the life of current equipment and infrastructure (i.e., asset management).

6.2 Existing System Demands and Capacity

Existing (2014) system demands are presented in Section 3. Future demands for the water treatment

facilities are summarized in Table 6-2 for the four IWMP planning scenarios.

As part of the WISE agreement, Aurora Water and Denver Water have agreed to supply up to 5,000

acre-feet per year starting in 2016 (Phase-in), increasing to 10,000 acre-feet per year in 2021 (Full

delivery) to the South Metro WISE authority. If the annual supply requirement is averaged throughout

the year, then maximum daily flows could be as high as 4.5 MGD beginning in 2016. The WISE

agreement includes flexibility that allows Aurora Water to supply WISE only when there is excess

capacity in the system (provided that the change in flow in a 24 hour period is less than 5 MGD for

Phase-in and less than 7 MGD for Full delivery).

The expected WISE delivery schedule is the reverse of Aurora Water’s normal monthly demand curve,

as shown in Figure 6-15, and, therefore, no WISE deliveries are expected during peak day. Because

the projects recommended in this section are based on peak day system demands, WISE deliveries are

not included in this evaluation.

5 The Aurora System Demand shown in Figure 6-1 is an idealized demand based on the average weekly

demands from 2002-2013. The WISE deliveries are based on a total yearly delivery of 10,000 acre-feet, with no

deliveries on the peak day and maximum deliveries during the winter months.



Figure 6-1. Ideal Annual System Demand and WISE Distribution

In the TWMP (CH2M Hill, 2012), the capacities of the Aurora Water’s WPFs were identified as

summarized in Table 6-1. The Mountain Water System, which includes the Rampart, Quincy, and

Aurora Reservoirs, provides the main raw water supply to Griswold WPF, Wemlinger WPF, and the

Aurora Reservoir (AR) train of the Binney WPF. The Prairie Waters System provides water to the

South Platte (SP) train of the Binney WPF. The current system capacity can provide a peak sustainable

production of 149 MGD.

The following assumptions and definitions are used in this section:

The total sustainable supply refers to the available raw water delivery capacity that can be

sustainably conveyed to the WPFs relative to existing raw water quality or hydraulic

infrastructure limitations, whichever is the more limiting factor.

The peak sustainable treatment capacity refers to the treatment capacity relative to permit rating,

operational challenges, or hydraulic limitations within the WPF.

The peak sustainable production refers to the effective treatment capacity relative to either the

total sustainable supply or the peak sustainable treatment capacity, whichever is limiting; this

capacity will allow continuous operation throughout the day, in order to meet the peak day

demand.

Peak hour demand will be met by storage in the finished water system.

All three plants are operational during peak day conditions.

All raw water supply and conveyance systems are fully operational during peak day conditions.

0

20

40

60

80

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Flo

w (

MG

D)

Aurora System Demand

WISE Distribution



Table 6-1. Existing Raw Water Supply and Treatment Capacities

(1) Griswold WPF Wemlinger WPF

Binney WPF Total

System Aurora

Reservoir Train South Platte Train

RAW WATER SUPPLY CAPACITY (MGD)

Gravity

Pipelines Rampart: 59/20 (2)

Rampart: 66/50 (3)

Aurora Reservoir: 130/21 (4)

Aurora

Reservoir: 80 (5)

Pumped

Systems

Quincy:

Firm: 5 (6)

Hydraulic: 24

Installed: 36

PW Pipeline: 50

PW Pumps: 20 (7)

Wells Cherry Creek Well

Field: 9

PW Riverbank Filtration: 10.8

PW Aquifer Storage and Recovery: 4-5

Total

Sustainable

Supply

34 (8) 71 80 10.8 195.8

TREATMENT CAPACITY (MGD) (9)

Rated 80 (10) 80 33.3 50

Filtration (one

filter offline) 100 80 33.3 50

Solids Handling 65 (11) 80 Not limiting (11) Not limiting (11)

Peak

Sustainable 65 80 33.3 50

Peak Sustainable Production (MGD)

Peak

Sustainable

Production (12)

34 71 33.3 10.8 149.1

NOTES: (1) These values in the table are for the purpose of achieving total maximum pipeline capacities and do not

represent true supply capacities or limitations to the individual treatment facilities. (2) The Rampart supply to Griswold WPF is limited to 20 MGD if water is also being supplied to Wemlinger WPF.

Otherwise, the supply to Griswold has a maximum of 59 MGD. (3) The Rampart supply to Wemlinger is limited to 50 MGD if water is also being supplied to Griswold WPF. When

Rampart is only supplying raw water to Wemlinger, the capacity is 66 MGD. (4) The hydraulic capacity of the Aurora Reservoir Pipeline is 130 MGD; however, in order to operate properly,

Wemlinger WPF limits the Aurora Reservoir contribution to 30% of the total Wemlinger feed flow. Because the maximum contribution available from Rampart Reservoir is 50 MGD when Griswold is also being supplied, the maximum flow from Aurora Reservoir is 21 MGD and the Wemlinger WPF maximum is 71 MGD.

(5) The pipeline is sized for 80 MGD but the actual capacity depends on the level in Aurora Reservoir. (6) Due to taste and odor events, flow from Quincy Reservoir is generally limited to 15% of total production. (7) Prairie Waters Pump Stations are designed for expansion to 50 MGD. (8) Total sustained raw water supply to Griswold WPF is 20 MGD from Rampart, 9 MGD from the Cherry Creek

Wells and 5 MGD (i.e., 15% of total production) from Quincy Reservoir. (9) Treatment capacity includes work at Binney WPF that will be completed in 2016 (filters and solids handling). (10) Rated capacity at Griswold WPF is limited by the filter backwash component of the solids handling system;

filters are rated at 100 MGD. (11) Solids Management Project currently under construction will render both AR and SP solids as not limiting;

actual unit process capacity is unknown. (12) Raw water quality can affect sustainable capacities at Wemlinger and Griswold since they are direct filtration

facilities.



6.3 Future System Demands and Capacity Required

The demand projections for the treatment analysis are based on the planning scenarios summarized

in Table 4-1. Specific projections, subdivided by scenario and by year, are summarized in Table 6-2.

Table 6-2. Water Demands by Year and Planning Scenario

Table 6-3 summarizes which scenarios can be satisfied by the existing capacity (i.e., current peak

sustainable production) for years 2015, 2025, 2035 and 2070. Based on a peak sustainable production

of 149 MGD, average day demands can be met with existing capacity, but additional capacity is needed

to meet 2070 peak day demands for all scenarios. Peak hour demands require more capacity for all

scenarios; however, this demand will be met through finished water storage. The planning year in

which the peak day demands are anticipated to exceed the existing system capacity is shown in Figure

6-2.

This figure also includes the capacity with Binney WPF offline, demonstrating when the Aurora Water

Treatment system loses redundancy and therefore must operate with only two plants online. At this

point, backup power to the Prairie Waters Pump Station and North Campus riverbank filtration (RBF)

wells is needed to provide redundancy on the Binney WPF source water.

Demand

Paramete

r

Scenario 1

Baseline Plus: average

growth, weather, and

hydrology, enhanced

conservation level

Scenario 2

Fast Growth: higher

growth, average weather

and hydrology, enhanced

conservation level

Scenario 3

Fast and Hot: high

growth, hot/dry weather,

hot/dry hydrology.

Enhanced conservation

level

Scenario 4

Hot Baseline:

Average growth, hot/dry

weather, hot/dry

hydrology, enhanced

conservation level

DEMANDS (MGD) BY YEAR AND SCENARIO

Year 2015 2025 2035 2070 2015 2025 2035 2070 2015 2025 2035 2070 2015 2025 2035 2070

Potable

Average

Day

44 49 55 85 46 53 61 103 51 59 68 116 50 55 61 95

Peak-Day 99 108 118 176 103 117 132 214 115 130 147 239 111 121 132 197

Peak-Hour 159 173 189 282 164 186 211 343 206 234 265 431 200 218 238 355



Table 6-3. Water Demands Satisfied by Existing Capacity

Scenario 1

Baseline Plus: average

growth, weather, and

hydrology, enhanced

conservation level

Scenario 2

Fast Growth: higher

growth, average weather

and hydrology, enhanced

conservation level

Scenario 3

Fast and Hot: high

growth, hot/dry weather,

hot/dry hydrology.

Enhanced conservation

level

Scenario 4

Hot Baseline:

Average growth, hot/dry

weather, hot/dry

hydrology, enhanced

conservation level

Peak Sustainable Production (MGD)

149.1

Demands (MGD) by Year and Scenario

Year 2015 2025 2035 2070 2015 2025 2035 2070 2015 2025 2035 2070 2015 2025 2035 2070

Potable

Average Day 44 49 55 85 46 53 61 103 51 59 68 116 50 55 61 95

Peak-Day 99 108 118 176 103 117 132 214 115 130 147 239 111 121 132 197

Peak-Hour 159 173 189 282 164 186 211 343 206 234 265 431 200 218 238 355

NOTE: The colors in the table indicate the ability of the system to meet the treated water demands that were developed in

Task 6-2 based on the peak sustained capacity of the Aurora Water System. Green shading denotes sufficient system

capacity, yellow shading indicates marginal system capacity (within 2 MGD), and red shading indicates insufficient capacity

to meet demands.

Figure 6-2. Water Demands by Year and Planning Scenario

0

50

100

150

200

250

2015 2020 2025 2030 2035 2040 2045 2050 2055 2060 2065 2070

De

man

ds/

Cap

acit

y in

MG

D





Peak Sustainable Production Peak Sustainable Production, Binney Offline

Existing Capacity Existing Capacity Reached Reached, Binney Offline

Scenario 1 2056 2021Scenario 2 2044 Already ReachedScenario 3 2036 Already ReachedScenario 4 2046 Already Reached



6.4 Proposed Capital Projects

The treatment projects proposed for the IWMP CIP are based on the projects described in the TWMP

(CH2M Hill, 2012) and the TWMP CIP Update (CH2M Hill, 2015). The order of projects presented

in this section does not reflect the intended project timing, which is discussed in Section 6.5.

6.4.1 RAMPART RAW WATER SYSTEM

The Rampart Raw Water System includes two pipelines: a 40/42-inch transmission line and a 54-inch

transmission line. This system provides raw water to both Griswold and Wemlinger WPFs, Aurora

Reservoir via Aurora Reservoir Pump Station, and Quincy Reservoir. The maximum capacity of the

Rampart Raw Water System is 70 MGD, assuming 20 MGD supplied to Griswold WPF and 50 MGD

supplied to Wemlinger WPF. The Griswold WPF supply is supplemented by Quincy Reservoir and

the Cherry Creek wells. Griswold WPF has a total sustainable supply of 34 MGD. The Wemlinger

WPF supply is supplemented by Aurora Reservoir, although that supply is limited to 30 percent of the

total flow. As a result, the total sustainable supply for Wemlinger WPF is 71 MGD. By increasing the

raw water available through the Rampart supply system, Griswold and Wemlinger WPFs would be

able to operate at their rated treatment capacities. Two options for conveying additional Rampart

supply are presented below; the options are mutually exclusive.

6.4.1.1 Holly Street Pump Station Expansion

The Holly Street Pump Station was originally constructed as an interim capacity improvement to add

16 MGD of capacity to the 40-inch Rampart Supply Pipeline prior to completion of the 54-inch

pipeline. The pump station has not been operational since 1980 following completion of the first

phase of the 54-inch pipeline. The 1997 Camp Dresser & McKee (CDM) Water Treatment Master Plan

(CDM, 1997) presented an option to increase the pump station capacity to 85 MGD by opening the

interties and sharing the suction between the 40-inch and 54-inch mains, and closing the discharge

interties and pressurizing the 40-inch pipeline; the 54-inch line would remain a gravity flow line. CDM

did not study a transfer capacity of 90 MGD, but the 2012 TWMP assumes 90 MGD is feasible.

Replacement of approximately 13,000 linear feet of poor condition 54-inch, pre-stressed concrete

cylinder pipe (PCCP) also would be required and has been included in the cost estimate.

6.4.1.2 New Rampart Supply Pipeline

The project would include a new 72-inch diameter pipeline that would parallel the existing Rampart

Delivery System pipelines from Rampart Reservoir to State Highway 470 (C-470), a new 66-inch

diameter pipe from C-470 to Quincy Avenue, and new 60-inch pipe from Quincy to the Griswold and

Wemlinger WPFs. This project would increase the Rampart system capacity to 125 MGD.

6.4.2 GRISWOLD WPF CAPACITY RECOVERY

Griswold WPF is currently unable to operate at its rated capacity of 80 MGD for an extended duration

due to the time required to clean the filters and limited solids handling capacity in the lagoons. These



issues limit the peak sustained treatment capacity to 65 MGD. Improvements to the backwash and

solids handling systems could increase plant capacity to the rated capacity of 80 MGD.

Capacity could be increased by minimizing the time required for a backwash. The TWMP states that

at 80 MGD, 22 cleans are required per day (one every 65 minutes) and each backwash plus filter-to-

waste (FTW) takes 75 minutes. Two options were included in the TWMP for filter backwash

improvements such that the rated plant capacity can be reliably maintained:

Increase the capacity of backwash and FTW systems such that an entire filter can be cleaned

at one time (the current system is only capable of cleaning one of two cells at a time). This

would reduce the total cleaning time by 22 minutes (53 minutes total).

Separate the backwash supply and FTW header so that one cell can be in FTW while the next

cell is beginning backwash. FTW currently requires at least 20 minutes therefore separating

these process would reduce the total cleaning time to 55 minutes.

If the filter cleaning time is reduced and the plant is able to sustain flow rates of 80 MGD, the lagoons

will likely become the limiting process at Griswold. The lagoons were determined to have sufficient

volume to handle backwash flows at plant operation of 80 MGD (CH2M Hill, 1999), but that

evaluation was completed before FTW was added in 2009. As stated in the TWMP, the FTW volume

may add up to 80,000 gallons of water per backwash event, depending on filter ripening time. At a

minimum, the backwash recycle pipeline that takes decant from the lagoons back to rapid mix is

undersized and needs to be replaced. The backwash recycle pumps are of sufficient size but require

variable frequency drives (VFDs) to optimize recycling of backwash water.

The alternatives suggested in the TWMP for increasing residuals drying capacity include:

Add a fourth lagoon, or

Add a backwash equalization basin/gravity thickener and retrofit one lagoon to act as a sand

drying bed.

Further study of alternative residuals handling also was recommended in the TWMP. For the IWMP,

it is assumed that adding a fourth lagoon will occur with the Lagoon Replacement/Addition project

in 2018.

Prior to implementing these capacity expansion projects, the 2012 TWMP unit filter run volume

assumption should be verified. The goal of implementing these improvements is to allow Griswold

WPF to operate sustainably at its rated capacity of 80 MGD.

6.4.3 BINNEY WPF – SOUTH PLATTE TRAIN BUILD-OUT

The existing capacity at Binney WPF is constrained at two points: raw water supply to the SP train

and dilution of finished SP train water. In order to increase the peak sustained treatment capacity for

the SP train, both of these constraints must be addressed.



Raw water for the SP train is supplied via RBF at the North Campus, which has an existing capacity

of 10.8 MGD. Storage of RBF supply during low demand periods is provided by the Aquifer Recharge

and Recovery (ARR) system. The ARR also was intended to provide additional treatment; however,

the required treated water quality goals are already being met by RBF while sustainable ARR capacity

is lower than anticipated. As a result, no additional ARR development is anticipated; additional storage

will be supplied by gravel lakes, although water quality issues (e.g., potential for algal growth) will need

to be identified and mitigated.

Because the raw water supplied to the SP train at Binney WPF is higher in TDS than the rest of the

Aurora Water System, use of SP water requires a 2:1 blend of finished AR water to finished SP water.

Currently, that dilution is provided by the blend between the AR and SP trains at Binney WPF, but

that limits the production of the SP train to 16.7 MGD as the AR train has a total capacity of 33.3

MGD. In order to utilize the full intended capacity of 50 MGD for the SP train, 33.3 MGD of filtered

SP water will be pumped to Wemlinger WPF (via the Wemlinger Blended Water Pipeline) and blended

with raw water from Aurora Reservoir or the Rampart Pipeline before receiving full treatment at

Wemlinger WPF; alternatively, disinfected SP water can be delivered to WISE.

6.4.3.1 Wemlinger Blended Water Pipeline and Pump Station

Installation of the Wemlinger Blended Water Pipeline will provide the ability to supply up to 80 MGD

of gravity-fed Aurora Reservoir water to the Wemlinger WPF. The pipeline was designed to 90 percent

completion in 2006. The Wemlinger Transfer Pump Station will allow the Blended Water Pipeline to

supply up to 33.3 MGD of filtered Binney SP water6 to the Wemlinger WPF, where it would be

combined with raw Rampart water and Aurora Reservoir water (supplied via the existing 60-inch bi-

directional pipeline) and receive further treatment. The pump station building was built during the

original construction of Binney WPF, but the pumps were not installed at that time.

The blending pipeline and pump station will provide additional raw water capacity to Wemlinger WPF,

helping to maximize the use of North Campus water, with the additional benefit of hardening the

supply. Reducing the Rampart supply to Wemlinger WPF also will result in increased Rampart supply

availability for Griswold WPF.

Supplying either Aurora Reservoir water or filtered SP water to Wemlinger WPF will allow the

simultaneous filling of Aurora Reservoir by the Mountain Water System. Should Wemlinger be fed

only Aurora Reservoir water via the existing 60-inch pipeline and the new blending pipeline

simultaneously, then Aurora Reservoir would be in a drawdown operational mode and cease to be

filled by the Mountain Water System.

6.4.3.2 Prairie Waters System Expansion 1: North Campus to 20 MGD

The North Campus is part of the Prairie Waters System, which was constructed to pre-treat and supply

South Platte water to the Binney WPF. The RBF wells, which provide the pretreatment, have a

6 Water will be collected from the SP train after filtration and before disinfection.



capacity of 10.8 MGD, while the conveyance system has a capacity of 50 MGD in the pipelines and

20 MGD in the pump stations.

Currently, the capacity of the North Campus is limited by the RBF wells. The CIP Update states that

“Potential sites on the East side of the South Platte have been identified to provide an additional

approximate 10 MGD (20 MGD total) of RBF capacity. Key project components include land

acquisition for the East Wellfield, new wells and collection pipelines, a river pipeline crossing to

connect the (existing) west and (future) east wellfield, and installation of Prairie Waters System

conveyance pumping equipment to increase the firm pump capacity by 5 MGD.” With these

improvements, the peak sustainable production of the SP train will be 20 MGD.


As stated in the TWMP CIP Update, the expansion of the North Campus to 30 MGD will consist of

“expanding RBF capacity from 20 MGD to 30 MGD, additional ARR capacity, and increased Prairie

Waters System conveyance pumping from 30 MGD to 45 MGD to take advantage of higher RBF

flows during elevated river stage conditions and ARR scalping of RBF flows.” As stated previously,

the ARR also was intended to provide additional treatment; however, the required treated water quality

goals are already being met by RBF while sustainable ARR capacity is lower than anticipated. As a

result, no additional ARR development is anticipated; additional storage will be supplied by gravel

lakes. This expansion will allow the SP train to reliably produce 30 MGD of water.

Due to economies of scale, it may be more cost effective to increase the North Campus capacity from

10.8 MGD to 30 MGD, without the intermediate 20 MGD project.


This expansion to the North Campus will increase RBF capacity to 40 MGD and Prairie Waters

System pumping capacity to 50 MGD. This project includes future well field development for the

Prairie Waters North Campus Expansion. Total capacity for Prairie Waters would increase from a

firm capacity of 30 MGD to 40 MGD. Key project components would include land acquisition for

proposed RBF, construction of a 10 MGD RBF wellfield and connecting pipelines (total RBF capacity

of 40 MGD), and build out of the PW conveyance pumping to the design capacity of 50 MGD.

6.4.3.5 Prairie Waters System Storage Project – Terminal Reservoir

In order to operate the Prairie Waters System at the 50 MGD pipeline and pumping capacity, storage

of the RBF water must be provided. Terminal Reservoir, discussed further in the Water Resources Project

Technical Report (MWH, 2016a), will provide sufficient storage throughout the year to allow deliveries

of 50 MGD to the SP train of Binney WPF. Terminal Reservoir is included in the water resources

portfolios and CIP.



6.5 Findings and Recommendations

There are two mutually exclusive options for expanding the Rampart Delivery System capacity: (1)

Holly Street Pump Station Expansion (increases Rampart supply capacity to 90 MGD); and (2)

Rampart Supply Pipeline Replacement (increases Rampart supply capacity to 125 MGD).

A comparative capacity analysis and cost estimates for these two options was conducted. The analysis

indicates that if the Rampart Supply Pipeline is fully replaced, it would provide sufficient raw water to

allow Wemlinger WPF and Griswold WPF to operate at their full capacities of 80 MGD each.7 By

comparison, if the Holly Street Pump Station was expanded, it would provide sufficient raw water to

allow Griswold WPF to operate at full capacity; yet, Wemlinger WPF would have a 27 MGD supply

deficiency. As a result, the Wemlinger Blended Water Pipeline and all Prairie Waters System expansion

projects (including Prairie Waters System Storage – Terminal Reservoir) would be required to provide

enough supply for Wemlinger WPF to operate at full capacity. However, the Wemlinger Blended

Water Pipeline and all Prairie Waters System expansion projects are required by the Water Resources

Portfolio CIP; therefore, the additional 90 MGD provided by the Holly Street Pump Station

Expansion will alone be sufficient for treatment needs at both Griswold and Wemlinger WPFs.7

The cost estimates confirm the Holly Street Pump Station Expansion project represents the lowest

total cost option, by an average of $248M, for each of the three planning scenarios considered.8 The

cost evaluation considered costs to Aurora Water beyond capital and operational costs. Specifically,

the results of the capacity analysis were used in conjunction with the historical cost of chemicals,

residuals handling, miscellaneous O&M, energy, and labor at each WPF to determine the overall

corresponding cost of treatment for each option.9

The treatment cost is of interest particularly for the Holly Street Pump Station Expansion, since this

option would result in filtered SP water being conveyed to Wemlinger WPF (via the Wemlinger

Blended Water Pipeline) for further treatment. As expected, the cost evaluation determined treatment

costs for this option to be an average of $22.1M higher than for the Rampart Supply Pipeline option.

However, this difference in treatment cost was not significant enough to offset the substantial

difference in project-specific O&M, energy, and capital costs. Therefore, considering the results of the

capacity analysis and the cost evaluation, only the Holly Street Pump Station Expansion has been

included within the Treatment CIP.

Total capital costs for each proposed project are summarized in Table 6-4. Cumulative capacity

increases resulting from implementation of each proposed project are summarized in Table 6-5. The

maximum system capacity of 210 MGD is defined by the ultimate treatment capacities of the three

7 This assumes that the Griswold Capacity Recovery project has increased the sustainable Griswold capacity

to 80 MGD. 8 Planning Scenario 1 (Baseline Plus) was not considered in the cost evaluation since additional capacity from

the Rampart Delivery System is not required for Treatment to meet peak day demand projections. 9 Aurora Water provided historical cost/MG figures for chemicals, residuals handling, O&M, and labor for each

WPF. Average cost/MG was used for each cost category and assumed to remain constant for the planning period.



WPFs (80 MGD for both Griswold and Wemlinger, 50 MGD for Binney). Projects listed in this table

are representative of the order of projects required to achieve ultimate treatment capacity at each WPF.

Table 6-4. Capital Costs of Proposed Treatment and Water Resources Projects Impacting Capacity

Project Capital Cost

Prairie Waters System North Campus Expansion 20 MGD $21.1

Wemlinger Blended Water Pipeline and Pump Station $58.8



Prairie Waters System Storage Project – Terminal Reservoir $327.7

Holly Street Pump Station Expansion10 $17.2

Griswold Water Purification Facility Capacity Recovery $5.5

10 Holly Street Pump Station estimated capital cost is based on the 2012 TWPM and also includes replacement

of 13,000 feet of 54 inch PCCP with ductile iron pipe.



Table 6-5. Cumulative Raw Water Supply and Treatment Capacities

Griswold Supply

Gri

sw

old

WP

F C

ap

acit

y

Wemlinger Supply

Wem

lin

ger

WP

F C

ap

acit

y

Binney

AR

Supply

Bin

ney A

R T

rain

Cap

acit

y

Binney

SP

Supply

Bin

ney S

P T

rain

Cap

acit

y

To

tal

Su

sta

ined

Cap

acit

y

Ram

pa

rt P

ipeli

ne

Qu

incy R

eserv

oir

Ch

err

y C

reek W

ell

s

Ram

pa

rt P

ipeli

ne

Au

rora

Re

serv

oir

11

Excess S

P C

ap

acit

y1

2

Au

rora

Re

serv

oir

Pra

irie

Wate

rs

Syste

m

Current Conditions 20 5 9 34 50 21 0 71 80 33.3 10.8 10.8 149

PW Expansion 1 (20 MGD) 20 5 9 34 50 21 0 71 80 33.3 20.0 16.7 155

Wemlinger Blended Water Pipeline 20 5 9 34 50 22 3 75 80 33.3 20.0 16.7 159

PW Expansion 2 (30 MGD) 27 6 9 42 43 24 13 80 80 33.3 30.0 16.7 172

PW Expansion 3 (40 MGD) 37 8 9 54 33 24 23 80 80 33.3 40.0 16.7 184

PW Storage Project – Terminal

Reservoir (50 MGD) 41 8 9 58 29 24 27 80 80 33.3 50.0 16.7 188


Expansion (90 MGD) 46 10 9 65 29 24 27 80 80 33.3 50.0 16.7 195

Griswold Improvements (80 MGD) 61 10 9 80 29 24 27 80 80 33.3 50.0 16.7 210

11 Aurora Reservoir water to Wemlinger WPF is currently supplied by the 60-inch bi-directional Aurora Reservoir pipeline; this conveyance occurs primarily

during the summer months. Following completion of the Wemlinger Blended Water Pipeline, Aurora Reservoir water to Wemlinger WPF can be supplied either via

this new pipeline, or via the existing 60-inch pipeline. 12 Treated SP water capacity is limited to 2:1 blending ratio to meet water quality total dissolved solids goal prior to being sent to the potable water system.

This approach limits Binney SP Train capacity to 16.7 MGD. Remaining Prairie Waters System supply capacity (up to 27 MGD) is treated at the SP Train through

filtration and then filtered SP water is conveyed to Wemlinger WPF (via the Wemlinger Blended Water Pipeline).



Seven projects, namely Wild Horse Reservoir, Prairie Waters North Campus Expansion 20 MGD,

Wemlinger Blended Water Pipeline, Prairie Waters North Campus Expansion to 30 MGD, Prairie

Waters North Campus Expansion to 40 MGD, Terminal Reservoir, and Holly Street Pump Station

Expansion were analyzed by MWH’s Treatment team and the Water Resources team to determine the

need for and timing of the projects. The final timing of the projects for the IWMP is based on the

earliest year the project is needed to meet demands either from the Water Resources or Treatment

perspective.

For Planning Scenarios 1 (Baseline Plus) and 4 (Hot Baseline), only a selection of the proposed options

from past studies will be required. For Planning Scenarios 2 (Fast Growth) and 3 (Fast and Hot),

despite completion of all proposed projects discussed in this section, a capacity deficit will still exist.

These scenarios are discussed in more detail below.

For all planning scenarios, when plant redundancy (i.e., 105 MGD) is lost, a backup power supply

must be added to the Prairie Waters System pump stations and the North Campus RBF wells. The

timing of that project is discussed in the sections below.

For all planning scenarios, the total Rampart supply capacity is dedicated to Griswold and Wemlinger

WPFs during peak day demand conditions. For this one-day period, Aurora Reservoir will cease to be

filled by the Rampart Delivery System. This drawdown is an outcome of maximizing the supply.

6.5.1 PLANNING SCENARIO 1 (BASELINE PLUS)

Proposed timing of the projects required to meet peak day demands under Planning Scenario 1

(Baseline Plus) are presented in Figure 6-3. The existing treatment system has sufficient capacity to

meet peak day demands until 2056. Plant redundancy is lost in 2022; at that time redundant power

will need to be installed at the Prairie Waters System pump stations and the North Campus RBF wells.

In this scenario, the Prairie Waters System would be expanded to 20 MGD by 2056, allowing the SP

train at Binney WPF to operate at its capacity of 16.7 MGD. Four years later, the construction of the

Wemlinger Blended Water Pipeline and Holly Street Pump Station would allow the excess capacity

from Binney SP Train to be delivered as raw water to Wemlinger (3.3 MGD). This will provide

sufficient system capacity until 2062, at which time the Prairie Waters System would be expanded to

30 MGD. The additional 10 MGD of Binney SP Train capacity also would be delivered as raw water

to Wemlinger (13.3 MGD total). This peak sustained system capacity of 172.3 MGD would be

sufficient for meeting peak day demands through 2070.



Figure 6-3. Planning Scenario 1 (Baseline Plus) Project Timing

6.5.2 PLANNING SCENARIO 2 (FAST GROWTH)

Proposed timing of the projects required to meet peak day demands under Planning Scenario 2 (Fast

Growth) are presented in Figure 6-4. The existing treatment system has sufficient capacity to meet

peak day demands for Planning Scenario 2 (Fast Growth) until 2045.


train at Binney WPF to operate at its capacity of 16.7 MGD. Two years later, the construction of the

Wemlinger Blended Water Pipeline and Pump Station would allow the excess capacity from Binney

SP Train to be delivered as raw water to Wemlinger (3.3 MGD). In 2049, Prairie Waters Expansion 2

would be required to increase capacity to 30 MGD. Six years later, Prairie Waters Expansion 3 will

increase RBF capacity to 40 MGD and the Prairie Waters System pumping capacity to 50 MGD which

will provide sufficient capacity until 2060 at which point the Terminal Reservoir and Holly Street

Pump Station projects would be implemented. Griswold improvements to the backwash and solids

handling systems would be required in 2064, resulting in the maximum system capacity of 210 MGD

based on the ultimate treatment capacities of the three WPFs (80 MGD for both Griswold and

Wemlinger, 50 MGD for Binney). With all improvements shown below, there will be a treatment

capacity deficit in 2069. Plant redundancy was lost in 2015; backup power supplies need to be installed

at the Prairie Waters System pump stations and the North Campus RBF wells.

Terminal Reservoir and Holly Street Pump Station were analyzed by both the treatment and water

resources teams; based on water resources requirements, Terminal Reservoir and Holly Street Pump

Station would be needed in 2050. Final timing of the projects for the IWMP are based on the earliest

year the project is needed to meet demands either from the water resources or treatment perspective.



159 MGD in 2060PWP Expansion 2172 MGD in 2062


20220

50

100

150

200

250

300

2015 2025 2035 2045 2055 2065

De

man

ds/

Cap

acit

y in

MG




Figure 6-4. Planning Scenario 2 (Fast Growth) Project Timing

6.5.3 PLANNING SCENARIO 3 (FAST AND HOT)

Proposed timing of the projects required to meet peak day demands under Planning Scenario 3 (Fast

and Hot) are presented in Figure 6-5. The existing treatment system has sufficient capacity to meet

peak day demands for Planning Scenario 3 (Fast and Hot) until 2036.


train at Binney WPF to operate at its capacity of 16.7 MGD. Three years later, the construction of the


SP Train to be delivered as raw water to Wemlinger (3.3 MGD). In 2041, the Prairie Waters System

Expansion 2 would be required to increase capacity to 30 MGD. Six years later, the Prairie Waters

System Expansion 3 will increase RBF capacity to 40 MGD and the Prairie Waters System pumping

capacity to 50 MGD, which will provide sufficient capacity until 2052, at which point the Terminal

Reservoir and Holly Street Pump Station projects would be implemented. Griswold improvements to

the backwash and solids handling systems would be required in 2056 resulting in the maximum system

capacity of 210 MGD based on the ultimate treatment capacities of the three WPFs (80 MGD for

both Griswold and Wemlinger, 50 MGD for Binney).

With all improvements described above, there will be a treatment capacity deficit in 2061. Plant

redundancy is already lost; backup power supplies need to be installed at the Prairie Waters System

pump stations and the North Campus RBF wells.



159 MGD in 2047

PWP Expansion 2172 MGD in 2049 PWP Expansion 3

184 MGD in 2055


188 MGD in 2060


195 MGD in 2061


210 MGD in 2064



20150

50

100

150

200

250

300

2015 2025 2035 2045 2055 2065

De

man

ds/

Cap

acit

y in

MG




Figure 6-5. Planning Scenario 3 (Fast and Hot) Project Timing

6.5.4 PLANNING SCENARIO 4 (HOT BASELINE)

Proposed timing of the projects required to meet peak day demands under Planning Scenario 4 (Hot

Baseline) from a treatment capacity perspective are presented in Figure 6-6. The existing treatment

system has sufficient capacity to meet peak day demands for Planning Scenario 4 (Hot Baseline) until

2047.


train at Binney WPF to operate at its capacity of 16.7 MGD. Three years later, the construction of the


SP Train to be delivered as raw water to Wemlinger (3.3 MGD). In 2052, the Prairie Waters System

Expansion 2 would be required to increase capacity to 30 MGD. Seven years later, the Prairie Waters

System Expansion 3 will increase RBF capacity to 40 MGD and the Prairie Waters System pumping

capacity to 50 MGD, which will provide sufficient capacity until 2065, at which point the Terminal

Reservoir and Holly Street Pump Station projects would be implemented. Griswold improvements to

the backwash and solids handling systems would be required in 2069, resulting in the maximum system

capacity of 210 MGD based on the ultimate treatment capacities of the three WPFs (80 MGD for

both Griswold and Wemlinger, 50 MGD for Binney). Plant redundancy is already lost; backup power

supplies need to be installed on the Prairie Waters System pump stations and the North Campus RBF

wells.



159 MGD in 2039




188 MGD in 2052


195 MGD in 2053


210 MGD in 2056


0

50

100

150

200

250

300

2015 2025 2035 2045 2055 2065

De

man

ds

/ C

apac

ity

in M

GD

Scenario 3 Peak Day Demand Scenario 3 Peak Sustained System Capacity

Redundant power at the PWP stations, Install now



Figure 6-6. Planning Scenario 4 (Hot Baseline) Project Timing



159 MGD in 2050




188 MGD in 2065


195 MGD in 2066


210 MGD in 2069

0

50

100

150

200

250

300

2015 2025 2035 2045 2055 2065

De

man

ds/

Cap

acit

y in

MG


Redundant power at

the PWP stations, Install now



7.0 Distribution

7.1 System Design Requirements

The T&D projects needed to adequately serve projected population growth up to 2070 were identified

in the IWMP and further refined in the T&D CIP Refinement Study (Refinement Study), conducted

by Water Plans, Inc. Projects were developed and verified using the City’s all pipes distribution system

hydraulic model and projected growth rates as estimated in a workshop attended by various

departments throughout the City.

The Refinement Study demands were updated using up to date water use data. The updated demands

were slightly higher than Planning Scenario 2 demands with a projected max day demand of 266.4

MGD for 2070.

A Population and Employment Allocation Tool (PEAT) was used to project the timing and location

of growth throughout the City. System demands were then distributed to model nodes throughout

the service area. To better reflect anticipated demands from high-use developments, specific model

nodes were adjusted with estimated demands for these developments. The high-use developments

include Niagara Bottling, Veterans Administration Hospital, Gaylord Resort, Fitzsimons Master Plan

Area and Buckley Air Force Base. The high-use developments collectively have an estimated max day

demand of 8.1 MGD, which would result in a total system max day demand of 274.5 MGD in 2070.

In order to accommodate future growth while utilizing the existing treatment capacity, the capital

improvements focus on conveying supply from Griswold and Wemlinger WPFs to the northeastern

portion of the City’s service area. The system improvements include a 60” pipeline conveying flows

from Wemlinger and Griswold northeast along with a new reservoir located in Pressure Zone 3 that

will serve the northeastern portion of the water system.

The Refinement Study also evaluated system pumping and storage capacity. The system pumping

capacity was analyzed to determine if the pump stations have adequate capacity to meet future

demands and redundancy requirements, the ability to provide the maximum pumping demand of the

system with the largest pump out of service. The storage capacity was evaluated to ensure the system

has adequate capacity to serve fire flow suppressions and meet emergency and equalization needs.

All projects are listed with Class 5 Opinion of Probable Construction Costs (OPCC). The T&D

projects are listed in Table 7-1, Table 7-2, and Table 7-3. Pump station and storage improvement

projects are shown in Table 7-4 and Table 7-5. Near-term projects phased from 2017 through 2020

are presented in Section 7.2, with remaining projects phased through 2070 described in Section 7.3.



Table 7-1. 2020 T&D Improvement Projects

Project Number

Phase Diameter Length (ft) Zone Project Name Description Aurora Water/ Developer

Construction Cost

Design 10% Permitting 5%

Total Project Cost

101 2020 36 10,700 3 Gun Club 36": 38th - 56th New 36''pipe, approximately 10700ft long, Parallel to

Gun Club, from E 38th Ave to E 56th Ave AW $10,039,000 $1,506,000 $11,545,000

101B 2020 36 5,200 3 Gun Club 36": 56th - 64th New 36''pipe, approximately 5200ft long, Parallel to

Gun Club, from E 56th Ave to E 64th Ave AW $4,879,000 $732,000 $5,611,000

102 2020 24 10,400 3, 3C Painted Prairie - 56th Ave 24": Himalaya - Picadilly New 24''pipe, approximately 10400ft long, Along E 56th Ave from Picadilly Rd to N Himalaya Rd, then

north along Himalaya Rd to E 64th Ave Painted Prairie $5,720,000 $858,000 $6,578,000

102B 2020 24 5,300 3 56th Ave 24": Picadilly - Gun Club New 24''pipe, approximately 5300ft long, Along E

56th Ave from Picadilly Rd to Gun Club Rd AW $3,915,000 $587,000 $4,502,000

103 2020 24 9,900 3 64th Ave 24": E-470 - Jackson Gap New 24''pipe, approximately 9900ft long, Along E

64th Ave from E-470 to N Jackson Gap St AW $6,445,000 $967,000 $7,412,000

103B 2020 24 2,500 3 64th Ave 24": Picadilly - E-470 New 24''pipe, approximately 2500ft long, Along E

64th Ave from E-470 to N Jackson Gap St Developer $1,375,000 $206,000 $1,581,000

104 2020 16 2,500 3C Painted Prairie - 60th Ave 16": Himalaya New 16''pipe, approximately 2500ft long, Along E

60th Ave east of Himalaya Rd Painted Prairie $920,000 $138,000 $1,058,000

105 2020 12 5,300 3C Painted Prairie 12": 56th - 64th New 12''pipe, approximately 5300ft long, Parallel to Himalaya Rd, between E 56th Ave and E 64th Ave

Painted Prairie $1,343,000 $201,000 $1,544,000

106 2020 24 15,300 5, 6, 7 Kings Point N - E-470 24": Dry Creek - Parker New 24''pipe, approximately 15300ft long, Parallel to

E470, from E Dry Creek Rd to S Parker Rd Kings Point

Development $8,415,000 $1,262,000 $9,677,000

107 2020 12 5,300 6, 7 Kings Point N & S 12" New 12''pipe, approximately 5300ft long, Pipe

segments off Project 106 Kings Point

Development $2,040,000 $306,000 $2,346,000

109 2020 12 6,900 8 Rocking Horse - Allens Park 12" New 12''pipe, approximately 6900ft long, Along E

Allens Park Pl, connecting to E Rocking Horse Pkwy Rocking Horse Development

$1,748,000 $262,000 $2,010,000

112 2020 16 15,100 3 6th Ave 16": Himalaya - Gun Club New 16''pipe, approximately 15100ft long, Localized

project near E 6th Pkwy and Picadilly Rd Developer $6,257,000 $939,000 $7,196,000

113 2020 12 7,700 4 Rome Way 12": Jewell - Gun Club New 12''pipe, approximately 7700ft long, Along S

Rome Way north of E Jewell Ave up to S Gun Club Rd

Developer $2,648,000 $397,000 $3,045,000

114 2020 60 7,000 3 Gun Club 60": 6th Ave - Colfax New 60''pipe, approximately 7000ft long, Along N

Gun Club Rd, north of E 6th Ave up to E Colfax Ave, then east parallel to I70

AW $13,723,000 $2,058,000 $15,781,000




Project Number

Phase Diameter Length (ft) Zone Project Name Description Aurora Water/

Developer Construction

Cost Design 10%

Permitting 5% Total Project Cost

108 2035 12 3,700 8A Kings Point S Prusse 12" New 12''pipe, approximately 3700ft long, Localized

project AW $938,000 $141,000 $1,079,000

201 2035 66 900 3 Griswold 66" New 66''pipe, approximately 900ft long, Griswold

WTP exit pipe, connecting to the transmission system

AW $1,576,000 $236,000 $1,812,000

202 2035 60 9,400 3 Yale Ave 60": Chambers - Tower New 60''pipe, approximately 9400ft long, Along E

Yale Ave from S Chambers Rd to S Tower Rd AW $14,897,000 $2,235,000 $17,132,000

202-U 2035 60 4,900 3 Yale Ave 60": Griswold - Chambers Upgrade existing pipe to 60'', approximately 4900ft long, Along E Yale Ave from Project 201 up to S

Chambers Rd AW $7,766,000 $1,165,000 $8,931,000

203 2035 60 38,500 3 Yale Ave 60": Tower - 6th & Gun Club

New 60''pipe, approximately 38500ft long, From E Linvale Dr and S Ventura St north upto Vassar Pl, then west up to S Telluride St, then south along S Sterling Hills Pkwy up to E Jewell Ave, then east to 1,500ft east of E470, then north 2,500 ft, then west crossing E 470, then north parallel to the highway,

up to E Mississippi Ave, then east up to S Gun Club Rd, then north up to E 6th Ave

AW $63,645,000 $9,547,000 $73,192,000

204 2035 48 23,500 3 Colfax Ave 48": Harvest - Hayesmount &

Alameda

New 48''pipe, approximately 23500ft long, Parallel to Colfax Ave, from N Harvest Rd east to N

Hayesmount Rd, then south to E Alameda Ave AW $31,122,000 $4,668,000 $35,790,000

204B 2035 60 2,800 3 Colfax Ave 60": Gun Club - Harvest New 60''pipe, approximately 2800ft long, Parallel to Colfax Ave, from N Gun Club Rd east to N Harvest

Rd AW $4,438,000 $666,000 $5,104,000

205 2035 30 21,500 3, 4 I70 Hwy 30": Hayesmount - Quail Run New 30''pipe, approximately 21500ft long, Parallel to E I70 Hwy, from N Hayesmount Rd to N Quail

Run Rd AW $16,770,000 $2,516,000 $19,286,000

206 2035 36 27,000 3 Hayesmount 36": I70 Hwy - 64th Ave New 36''pipe, approximately 27000ft long, Along N

Hayesmound Rd, from E I70 Hwy to E 64th Ave AW $25,333,000 $3,800,000 $29,133,000

207 2035 24 20,700 3, 4 Quail Run 24": I70 Hwy - 56th Ave New 24''pipe, approximately 20700ft long, Along N

Quail Run Rd from E I70 Hwy to E 56th Ave AW $11,385,000 $1,708,000 $13,093,000

208 2035 12 21,300 3 56th Ave 12": Hayesmount - Quail Run New 12''pipe, approximately 21300ft long, Along E 56th Ave from N Hayesmount Rd to N Quail Run

Rd Developer $5,397,000 $810,000 $6,207,000

209 2035 24 13,900 3 56th Ave 24": Jackson Gap - Hayesmount New 24''pipe, approximately 13900ft long, Along E 56th Ave from N Jackson Gap St to N Hayesmount

Rd AW $7,645,000 $1,147,000 $8,792,000

210 2035 12 10,600 3 Harvest 48": I70 Hwy - 38th Ave New 48''pipe, approximately 10600ft long, Along N

Harvest Rd from E I70 Hwy to E 38th Ave AW $2,686,000 $403,000 $3,089,000

211 2035 16 5,000 3 26th Ave 16": Gun Club - Harvest New 16''pipe, approximately 5000ft long, Along E 26th Ave from N Gun Club Rd to N Harvest Rd

AW $1,840,000 $276,000 $2,116,000

212 2035 24 7,000 3 Colfax Ave 24": Picadilly - Gun Club New 24''pipe, approximately 7000ft long, Parallel to Colfax Ave from N Picadilly Rd to N Gun Club Rd

AW $4,850,000 $728,000 $5,578,000

213 2035 12 4,700 3 38th Ave 12": Picadilly – Gun Club New 12''pipe, approximately 4700ft long, Along E

38th Ave from N Picadilly Rd to E 470 Developer $1,191,000 $179,000 $1,370,000

214 2035 36 21,000 3 38th Ave 36": Gun Club - 48th & Monaghan New 36''pipe, approximately 21000ft long, Along E

38th Ave from Gun Club to N Harvest Rd, then north to E 48th Ave, then east to N Monaghan Rd

AW $19,703,000 $2,956,000 $22,659,000

214-U 2035 36 30 3 38th Ave 36": Gun Club A 30 ft long pipe that will be upsized from 24” to

36”. AW $28,000 $4,000 $32,000

215 2035 12 10,400 3 26th Ave & 38th Ave 12": Harvest - Powhaton New 12''pipe, approximately 10400ft long, Parallel

lines along E 26th Ave and E 38th Ave from N Harvest Rd to N Powhaton Rd

Developer $2,635,000 $395,000 $3,030,000




Project Number

Phase Diameter Length (ft) Zone Project Name Description Aurora Water/

Developer Construction

Cost Design 10%

Permitting 5% Total Project Cost

216 2035 12 20,800 3 Powhaton Rd & Monaghan Rd 12": 56th Ave -

38th Ave

New 12''pipe, approximately 20800ft long, Parallel lines along N Powhaton Rd and N Monaghan Rd

from E 56th Ave to E 38th Ave Developer $5,271,000 $791,000 $6,062,000

218 2035 24 5,200 4 6th Ave 24": Powhaton - Monaghan New 24''pipe, approximately 5200ft long, Along E 6th Ave from N Powhaton Rd to N Monaghan Rd

AW $2,860,000 $429,000 $3,289,000

219 2035 12 32,200 4 Monaghan Rd 12": Alameda - 38th Ave &

Powhaton

New 12''pipe, approximately 32200ft long, Along N Monaghan Rd from E Alameda Ave to E 38th Ave and two parallel lines along E 26th Ave and E 38th

Ave from N Monaghan Rd to N Powhaton Rd

Developer $8,857,000 $1,328,000 $10,185,000

220 2035 24 5,100 3 56th Ave 24": Gun Club - Harvest New 24''pipe, approximately 5100ft long, Along E

56th Ave from N Gun Club Rd to Harvest Rd Developer $2,805,000 $421,000 $3,226,000

221 2035 24 17,400 3 64th Ave 24": Jackson Gap - Hayesmount New 24''pipe, approximately 17400ft long, Along E 64th Ave from N Jackson Gap St to N Hayesmount

Rd, and then north to E 68th Ave AW $9,570,000 $1,436,000 $11,006,000

222 2035 16 10,600 3 Watkins 16": 56th Ave - 72nd Ave New 16''pipe, approximately 10600ft long, Along N

Watkins Rd from E 56th Ave up to E 72nd Ave AW $3,901,000 $585,000 $4,486,000

223 2035 12 21,100 3, 4 38th Ave 12": Quail Run - Schumaker New 12''pipe, approximately 21100ft long, Along E 38th Ave from N Quail Run Rd to N Schumaker Rd

AW $5,347,000 $802,000 $6,149,000

224 2035 12 2,000 8A Kings Point S Prusse2 12" New 12''pipe, approximately 2000ft long, Segment

at the end of Project 108 Developer $507,000 $76,000 $583,000

225 2035 12 11,600 8 Butterfield Trails 12" New 12''pipe, approximately 11600ft long, Loop

east of S Monaghan Rd, north of E County Line Rd Developer $2,939,000 $441,000 $3,380,000

226 2035 8 23,300 8 Powhaton & Smoky Hill 8" New 8''pipe, approximately 23300ft long, Localized projects east and west near S Powhaton Rd and E

Smoky Hill Pkwy Developer $3,319,000 $498,000 $3,817,000

227 2035 24 8,300 7 Arapahoe 24": Powhaton - Aurora Pkwy New 24''pipe, approximately 8300ft long, Along E

Arapahoe Rd between S Powhaton Rd and S Aurora Pkwy

AW $5,565,000 $835,000 $6,400,000

228 2035 12 4,200 7 Southshore 12" New 12''pipe, approximately 4200ft long, Localized project east of E Euclid Dr and E South Shore Pkwy

Developer $1,064,000 $160,000 $1,224,000

229 2035 12 3,200 6 Belleview & Whitaker 12" New 12''pipe, approximately 3200ft long, Pipe

extension west of E Belleview Ave and E Whitaker Dr

Developer $811,000 $122,000 $933,000

233 2035 16 13,800 3, 4 Powhaton 16": Colfax - 38th Ave New 16''pipe, approximately 13800ft long, Along N

Powhaton Rd from E I70 up to E 38th Ave AW $5,778,000 $867,000 $6,645,000

234 2035 36 5,300 3 Gun Club 36": 26th Ave - 38th Ave New 36''pipe, approximately 5300ft long, Along Gun

Club Rd from 26th Ave to 38th Ave AW $4,973,000 $746,000 $5,719,000




Project Number Phase Diameter Length (ft) Zone Project Name Description Aurora Water/

Developer Construction Cost


Total Project Cost

301 2070 48 15,700 5 Quincy 48": Powhaton - Private Quincy & Yale New 48''pipe, approximately 15700ft long, East from E Quincy Ave and S Powhaton Rd up to E Private Quincy Ave, then North up to E Yale Ave

AW $19,523,000 $2,928,000 $22,451,000

302 2070 16 1,600 3 Alameda & Gun Club 16" New 16''pipe, approximatelly 1600ft long, east

from S Gun Club Rd and E Alameda Ave AW $589,000 $88,000 $677,000

302B 2070 12 8,800 3 Alameda & Gun Club 12" New 12''pipe, approximatelly 8800ft long, looped

east from S Gun Club Rd and E Alameda Ave AW $2,230,000 $334,000 $2,564,000

303 2070 60 22,900 4 Powhaton 60": Jewell - Alameda & Hayesmount

New 60''pipe, approximately 22900ft long, North/northwest from E Jewell Ave and E Yale Ave, up to S Powhaton Rd, then north up to E

Alameda Ave, then east up to S Hayesmount Rd, then north to the Proposed Tank (Alameda

Reservoir)

AW $36,293,000 $5,444,000 $41,737,000

304 2070 16 22,600 4 Harvest 16": Jewell - Alameda

New 16''pipe, approximately 22600ft long, Parallel (west) of S Powhaton Rd, from E Jewell Ave up to E Alameda Ave, and pipes along E Mississippi Ave

and S Haleyville St from S Harvest Rd and S Powhaton Rd

AW $8,317,000 $1,248,000 $9,565,000

305 2070 16 18,400 4 Monaghan Rd 16": Alameda - Jewell & Powhaton

New 16''pipe, approximately 18400ft long, Along E Jewell Ave from 1,000ft west of E Yale Ave, up to S Monaghan Rd, then north up to E Alameda Ave,

pipe segment from S Monaghan Rd, along S Haleyville St to connect with Project 304

AW $6,771,000 $1,016,000 $7,787,000

306 2070 16 8,000 4 Monaghan Rd 16": Alameda - 6th Ave New 16''pipe, approximately 8000ft long, Parallel

to S Monaghan Rd (east), from E Alameda Ave up to E 6th Ave, then west up to N Monaghan Rd

AW $2,944,000 $442,000 $3,386,000

307 2070 30 25,500 4 Hayesmount 30": Alameda - Colfax & Imboden

New 30''pipe, approximately 25500ft long, From proposed tank (Alameda Reservoir) along S

Hayesmount Rd north up to E Colfax Ave, then east parallel to E I70 Hwy up to N Imboden Rd

AW $20,990,000 $3,149,000 $24,139,000

308 2070 12 5,100 3, 4 I70 Hwy 12": Monaghan - Hayesmount New 12''pipe, approximately 5100ft long, Parallel to E I70 Hwy (south) from N Monaghan Rd to N

Hayesmount Rd AW $1,292,000 $194,000 $1,486,000

309 2070 12 29,800 3 Hudson Rd 12": I70 Hwy - 71st Ave New 12''pipe, approximately 29800ft long, Along N

Hudson Rd from E I70 Hwy up to E 71st Ave AW $7,551,000 $1,133,000 $8,684,000

310 2070 12 10,500 3 64th Ave 12": Hayesmount - Watkins New 12''pipe, approximately 10500ft long, Along E 64th Ave from N Hayesmount Rd up to N Watkins

Rd AW $2,661,000 $399,000 $3,060,000

311 2070 24 12,200 3 72nd Ave 24": Hayesmount - Watkins

New 24''pipe, approximately 12200ft long, Parallel (south) to E 72nd Ave from N Hayesmount Rd up

to N Hudson Rd, then north up to E 72nd Ave, then east up to N Watkins Rd

AW $6,710,000 $1,007,000 $7,717,000

312 2070 12 5,400 3 Valleyhead St 12": 56th Ave - 64th Ave New 12''pipe, approximately 5400ft long, Along N Valleyhead St from E 56th Ave up to E 64th Ave

AW $1,368,000 $205,000 $1,573,000

313 2070 12 26,900 3, 4 38th Ave 12": Monaghan - Quail Run New 12''pipe, approximately 26900ft long, Along E 38th Ave from N Quail Run Rd to N Monaghan Rd

AW $6,817,000 $1,022,000 $7,839,000

314 2070 12 32,000 3, 4 26th Ave 12": Monaghan - Cavanaugh New 12''pipe, approximately 32000ft long, Along E 26th Ave from N Cavanaugh Rd to N Monaghan

Rd AW $8,109,000 $1,216,000 $9,325,000

315 2070 36 26,700 3 48th Ave 36": Monaghan - Quail Run Rd New 36''pipe, approximately 26700ft long, Along E 48th Ave from N Monaghan Rd up to N Quail Run

Rd AW $25,052,000 $3,758,000 $28,810,000

316 2070 16 5,300 3 Watkins 16": 48th Ave - 56th Ave New 16''pipe, approximately 5300ft long, Along N

Watkins Rd from E 56th Ave up to E 48th Ave AW $1,950,000 $293,000 $2,243,000







Total Project Cost

317 2070 30 15,400 3 Watkins 30": I70 Hwy - 48th Ave New 30''pipe, approximately 15400ft long, Along N

Watkins Rd from E I70 Hwy to E 48th Ave AW $12,012,000 $1,802,000 $13,814,000

318 2070 12 20,800 3, 4 Imboden 12": I70 Hwy - 56th Ave New 12''pipe, approximately 20800ft long, Along N

Imboden Rd from E I70 Hwy to E 56th Ave AW $5,271,000 $791,000 $6,062,000

319 2070 24 21,200 3 48th Ave 24": Quail Run - Schumaker New 24''pipe, approximately 21200ft long, Along E 48th Ave from N Quail Run Rd to N Schumaker Rd

AW $11,660,000 $1,749,000 $13,409,000

320 2070 24 21,300 4 I70 Hwy 24": Quail Run - Schumaker New 24''pipe, approximately 21300ft long, Parallel

to E I70 Hwy from N Quail Run Rd to N Schumaker Rd

AW $11,715,000 $1,757,000 $13,472,000

321 2070 24 15,700 3, 4 Schumaker 24": I70 Hwy -48th Ave New 24''pipe, approximately 15700ft long, Along N

Schumaker Rd from E I70 Hwy to E 48th Ave AW $8,635,000 $1,295,000 $9,930,000

322 2070 12 20,800 3, 4 Cavanaugh 12": I70 Hwy - 56th Ave New 12''pipe, approximately 20800ft long, Along N

Cavanaugh Rd from E I70 Hwy to E 56th Ave AW $5,271,000 $791,000 $6,062,000

323 2070 16 20,900 3, 4 Manila 16": I70 Hwy - 56th Ave New 16''pipe, approximately 20900ft long, Along N

Manilla Rd from E I70 Hwy to E 56th Ave AW $7,691,000 $1,154,000 $8,845,000

324 2070 12 20,900 3, 4 Peterson Rd 12": I70 Hwy - 56th Ave New 12''pipe, approximately 20900ft long, Along N

Peterson Rd from E I70 Hwy to E 56th Ave AW $5,296,000 $794,000 $6,090,000

325 2070 12 26,500 3 56th Ave: Quail Run - 48th Ave & Schumaker New 12''pipe, approximately 26500ft long, From N

Quail Run Rd along E 56th Ave up to N Schumaker Rd and then south to E 48th Ave

AW $6,715,000 $1,007,000 $7,722,000

326 2070 24 21,600 3 Colfax 24": Tower - 38th Ave & Picadilly

New 24''pipe, approximately 21600ft long, From N Tower Rd east along E Colfax Ave up to N

Picadilly Rd, then north along N Picadilly Rd, up to E 38th Ave

AW $12,880,000 $1,932,000 $14,812,000

327 2070 12 3,900 6 Powhaton & Yale 12" New 12''pipe, approximately 3900ft long, Localized

project west of S Powhaton Rd and E Yale Ave AW $988,000 $148,000 $1,136,000

328 2070 12 16,000 4 26th Ave 12": Cavanaugh - Schumaker New 12''pipe, approximately 16000ft long, Along E

26th Ave from N Cavanaugh Rd up to N Schumaker Rd

AW $4,054,000 $608,000 $4,662,000

329-U 2070 60 10,800 3 Tower 60": Quincy - Yale

Upgrade existing pipe to 60'', approximately 10800ft long, Along S Tower Rd, from Wemlinger

Treatment Plant up to proposed Valve Station on E Yale Ave and E LinVale Dr

AW $17,116,000 $2,567,000 $19,683,000

330 2070 24 400 4 Powhaton 24": Colfax New 24''pipe, approximately 400ft long, South of I-

70 and N Powhaton Rd AW $220,000 $33,000 $253,000

330-U 2070 24 4,000 4 Powhaton 24": 6th Ave - Colfax Upgrade existing pipe to 24'', approximately 4000ft long, Along N Powhaton Rd from E 6th Ave up to

E Colfax Ave AW $2,200,000 $330,000 $2,530,000

331-U 2070 36 5,500 8 Powhaton 36": County Line - Smoky Hill Upgrade existing pipe to 36'', approximately 5500ft long, Along S Powhaton Rd, from Blackstone Tank

north up to E Smoky Hill Pkwy AW $5,160,000 $774,000 $5,934,000

332-U 2070 54 800 4 Binney 54" Upgrade existing pipe to 54'', approximately 800ft

long, Discharge line at Binney Treatment Plant Pump Station

AW $1,130,000 $170,000 $1,300,000

333 2070 36 5,300 4 Powhaton 36": Alameda - 6th Ave New 36''pipe, approximately 5300ft long, Along N

Powhaton Rd from E Alameda Ave up to E 6th Ave AW $4,973,000 $746,000 $5,719,000

334 2035 30 10,400 5 Yale 30": Powhaton - Hayesmount New 30''pipe, approximately 10400ft long, Along E

Yale Ave, from S Powhaton Rd up to S Hayesmount Rd

AW $8,112,000 $1,217,000 $9,329,000







Total Project Cost

335 2035 24 14,400 5 Hayesmount 24": Yale - Monaghan & Jewell

New 24''pipe, approximately 14400ft long. Along E Jewell Ave from S Powhaton Rd to S Hayesmount Rd and along Hayesmount Rd from Jewell Ave to

Yale Ave

AW $7,920,000 $1,188,000 $9,108,000

336 2035 16 11,100 5 Monaghan 16": Yale - Jewell New 16''pipe, approximately 11100ft long, Pipes

off Project 231 (on E Jewell Ave), along S Monaghan Rd and S Hayesmount Rd

AW $4,085,000 $613,000 $4,698,000

Table 7-4. Pump Station Improvement Projects

Project Number Phase Description Justification Pressure

Zone

Proposed Replacement Unit

Capacity (gal)

Proposed Replacement Unit

Capacity (HP)

Construction Cost ($)


Total Project Cost

501 2020 Eagle Bend PS Upgrade - Phase 1, replacement of existing 1,165 gpm unit with a 2,000 gpm unit.

Upgrade to meet performance criterion - redundancy requirements

8A 2,000 120 $600,000 $90,000 $690,000

502 2070 Eagle Bend PS Upgrade - Phase 2, replacement of existing 225 gpm unit with a 1,000gpm unit


8A 1,000 60 $300,000 $45,000 $345,000

503 2020 Gun Club Zone 6 PS - Phase 1, replacement of existing 500 gpm unit with 2,800 gpm unit


6 2,800 120 $600,000 $90,000 $690,000

504 2070

Gun Club Zone 6 PS - Phase 2, replacement of existing 2,000 gpm units with 4,000 gpm units and add a new 4,000gpm unit to station. Verify if there is room for another unit.


6 12,000 500 $2,500,000 $375,000 $2,875,000

505 2070 Powhaton PS Upgrade, replacement of 450gpm unit with a 4,000gpm unit.


8 4,000 190 $950,000 $143,000 $1,093,000

Table 7-5. Storage Improvement Projects

Project Number Phase Description Justification Pressure

Zone Total Volume

(gal) Construction

Cost

Design 10% Permitting

5%

Land Acquisition

Costs

Total Project Cost

401 2035 Additional Zone 7 Tank near Blackstone Meet storage requirements 7 4,200,000 $8,400,000 $1,260,000 $5,920,000 $15,580,000

402 2070 Additional Tank at Robertsdale Reservoir

Meet storage requirements 4 5,000,000 $10,000,000 $1,500,000 $0 $11,500,000

403 2035 New storage reservoir at Alameda and Hayesmount

Meet storage requirements 3 12,000,000 $24,000,000 $3,600,000 $4,800,000 $32,400,000



7.2 Near-Term Projects

This section will summarize the capital improvement projects identified through 2020. Improvements

needed through 2020 aim to reinforce the existing service area while laying the foundation for future

growth in the north.

Several capital improvements for 2020 are located in the northern part of the City near the High Point

area, which is currently experiencing significant growth. Gaylord, one of the high water users identified

in Section 7.1, is located in this area and is currently under construction. In order to meet the projected

demands in this area and provide system redundancy, Projects 101 through 105 have been included.

One of the major near-term capital improvements is project 101 and 101 B, a 36” pipeline along Gun

Club from 38th Ave to 64th Ave. This pipeline will provide redundancy by creating a second feed to

the northern part of the City. Projects 102, 104, and 105 reinforce the infrastructure for the Painted

Prairie, Single Tree, and Moffitt developments, which are located just south of High Point. The

pipelines for these projects range from 12” to 24”. Projects 102, 104 and 105 will be constructed by

the Painted Prairie development while Project 102B will be constructed by Aurora Water and cost

shared with the developers adjacent to the pipeline.

Also located in the northern part of the City are Projects 103 and 103 B, a 24” pipeline along 64th from

Picadilly Rd to Powhaton. This pipeline will connect with the existing 24” pipeline along Jackson Gap

St creating a looped system that will provide a second feed to the Porteos development.

On the southern side of the City, Projects 106 and 107 have been identified to serve the Kings Point

developments and will be constructed by Kings Point as the area is developed. Project 109 has also

been identified to meet the demands in the Rockinghorse development and will be installed by

Rockinghorse as the development continues to grow.

Projects located in the central part of the City include Projects 112 and 113, 16” and 12” lines

respectively, that will be needed to support future growth located just east of Buckley Air Force Base.

These projects are expected to be the responsibility of developers in the area.

Project 114 is another capital project located in the central part of the City. It is a 60” pipeline along

N Gun Club Rd north of 6th Ave. This pipeline is part of the backbone infrastructure needed to

reinforce the existing infrastructure and help convey flows to the northeastern parts of the City.

The pump station improvements needed by 2020 include an upgrade at Eagle Bend PS (Project 501)

and Gun Club Zone 6 PS (Project 503). The upgrades are needed so the pump stations can meet

redundancy requirements.



7.3 Long-Term Projects

The balance of the projects were phased for completion in 2035 and 2070. Through 2035, system

improvements support the expansion of the service area and deliver associated demands by

reinforcing and building off of the existing distribution system. By 2070 a significant amount of system

improvements are focused on the eastern and northeastern side of the City to accommodate future

growth.

Significant 2035 capital improvement projects include the 60” pipeline designed to convey flows from

Wemlinger and Griswold northeast (Projects 201 through 203) and the new 10 MG storage reservoir

located in Pressure Zone 3 (Project 403). This infrastructure will be critical for the system to be able

to meet demands in the northeastern part of the City.

The majority of the remaining 2035 projects are focused on conveying flows to the northern parts of

the City. These projects range from 12” to 48” and will primarily be located in areas that are currently

undeveloped. The projects will serve demands as far northeast as the Transport development and as

far north as the City limits. Some of the larger infrastructure includes a 48” pipeline (Project 210 and

214) along Harvest from Colfax Ave to 48th Ave, which will help convey additional flows to the north;

a 36” pipeline (Project 206) along Hayesmount Rd from I-70 to 64th Ave, which will also serve

demands in the northern part of the City; and a 60” (Project 204B) that turns into a 48” (Project 204)

and then a 30“ (Project 205) along I-70 from Harvest to Quail Run Rd, which will serve the Transport

development.

There are also capital improvements located in the eastern part of the City around the Cottonwood

Creek development, and the southern part of the City in the Southshore and Butterfield Trails

developments.

In addition to the new 10MG storage reservoir located in Pressure Zone 3 (Project 403) a new 3.5

MG Zone 7 tank will be needed by 2035 located in the Blackstone area.

The 2070 improvements are primarily focused on conveying flows to the northeastern and eastern

parts of the City. By 2070 Wemlinger will be connected to the 60” pipeline designed to convey flows

to the northeast with its own 60” branch of infrastructure (Project 329). There will also be a 60”

pipeline along Powhaton Rd from Jewell Ave to Alameda and along Alameda from Powhaton Rd to

Hayesmount Rd (Project 303) that will convey flows to and from the new 10 MG storage reservoir.

Other key improvements include a 36” pipeline along 48th Ave from Monaghan Rd east to the

Transport development (Projects 315 and 319). The remaining 2070 T&D proposed infrastructure

will serve developments such as ACRE, Transport and Eastern Hills.

In addition to the T&D infrastructure, an additional 4.1 MG tank will be needed at Robertsdale Pump

Station. The Eagle Bend PS, Gun Club Zone 6 PS, and Powhaton PS will also need to be upgraded

to meet redundancy requirements.



7.4 Capital Improvement Plan

The CIP is comprised of both Aurora Water funded projects and those anticipated to be built and financed by developers. The 2020 projects that are expected to be funded by Aurora Water are labeled “AW” in Table 7-1. For the purposes of the IWMP, it is assumed that about 50% of the 2035 and 2070 T&D projects would be the financed by developers and the other 50% would be funded by Aurora Water. The pump station and storage improvements are assumed to be financed by Aurora Water. The total Class 5 OPCC along with design and permitting cost allocated at 10% and 5% of capital costs respectively are summarized in Table 7-6.

Table 7-6. Distribution CIP Total Cost by Year and Project Category

Year Item Capital Cost Design and Permitting

Total Cost

2020 Transmission and Distribution Main $39,001,000 $5,850,000 $44,851,000

Pump Station and Storage $1,200,000 $180,000 $1,380,000

Subtotal $40,201,000 $6,030,000 $46,231,000


Pump Station and Storage $32,400,000 $4,860,000 $47,980,000

Subtotal $176,106,000 $26,419,000 $213,245,000


Pump Station and Storage $13,750,000 $2,063,000 $15,813,000

Subtotal $164,886,000 $24,734,000 $189,620,000

Grand Total $381,193,000 $57,183,000 $449,096,000



8.0 CIP Prioritization and Results

8.1 CIP Prioritization

The last step in the IWMP was to prepare an integrated CIP by prioritizing capital projects across the

technical disciplines including water resources, treatment, and T&D projects.

The most successful CIP prioritization frameworks share three important characteristics:

They are well-understood and supported by all levels of the organization (not just

engineering/planning)

The amount of rigor required to power the framework and related models, in terms of data

collection and use (e.g., estimating cost, determining return on investment [ROI], measuring

benefits), is well understood and “right-sized” for the process

They are powered by proven decision-support methodologies that account for both qualitative

and quantitative factors

To support each of these characteristics, the CIP prioritization approach engaged Aurora Water

stakeholders at all levels, integrated holistic triple bottom line (TBL) criteria data, and leveraged “multi-

criteria decision analysis” (MCDA) decision support best practices to produce a prioritized portfolio

of CIP projects.

Over the course of multiple planning sessions and workshops, MWH and Aurora Water outlined a

CIP prioritization process summarized in the following sections.

8.2 Approach

8.2.1 OVERVIEW

A work flow was established that ensured all relevant components of the initial proposed prioritization

process were integrated into the CIP effort and that all key methodologies could be incorporated. The

initial proposed decision framework is detailed in Figure 8-1; however, given the nature of decision

support analyses and modeled output, emphasis was placed on the ability to iterate and flex the process

to accommodate new insights derived from the method. The over-arching aim of the initial process

was to deliver a decision support framework that enabled selection of the most appropriate portfolio

of projects for Aurora Water’s 10 year CIP horizon.



Figure 8-1. Initial Prioritization Process

There are a number of different methodologies available to score and prioritize projects when

determining their relative value in a portfolio. In Aurora Water’s case, it was determined that a more

holistic project valuation approach should be utilized where not only financial benefits are considered,

but also broader social, economic, and environmental considerations.

Expert Choice was used as the project prioritization tool. Although Expert Choice served the primary

prioritization process needs, auxiliary tools also were required to facilitate a successful decision support

deployment at Aurora Water. This included a project database to facilitate project data management

and controls and supplementary Excel files to allocate weighted scores to projects and analyze the

outputs from Expert Choice.

8.2.2 CRITERIA DETERMINATION, WEIGHTING, AND SCORING

One of the first major steps in the prioritization process was the development of the framework’s

decision criteria. This process required input from all stakeholders and was imperative to the

framework’s overall success for a number of reasons, including:



1. Helping ensure capital projects align with organizational objectives and overall strategy

2. Integrating public/stakeholder values into project selection

3. Removing business unit bias or “noise” from decision process

4. Incorporating diverse benefit streams (beyond purely monetized benefits) into capital

decisions

5. Increasing transparency and defensibility in capital decision process

To ensure quality and differentiation in portfolio prioritization outputs, the measures were given

significant attention and vetted by both the MWH and Aurora Water prioritization participants in the

process. A mix of rating scales and utility curves13 were used to apply the most applicable and accurate

approach towards measuring the relative project values against each criterion. The resulting output

from related workshops and meetings was a final list of criteria and respective measures (Table 8-1).

13 Utility curve refers to a simple linear distribution feature available in Expert Choice software and can be used to

translate a range of quantitative values into a max/min distribution



Table 8-1. Final TBL Prioritization Criteria

Aurora IWMP Criteria Definitions

ECONOMIC CRITERIA Tier 3 Measure Lowest Rating (0) (0.25) (0.50) (0.75) Highest Rating (1) Definitions:

Growth & Economic Development Revenue Impact Scale 0 MGD,

0 people

Up to 2 MGD, 6,000 people >2-6 MGD, 6,001-8,000

people

>6-10 MGD, 8,001-30,000

people

>10-20 MGD, 30,001-60,000+

people

Impacts expanding the customer base and / or increasing

revenues

Operational Efficiencies OPEX savings relative to

Status Quo

Estimated <1% cost savings

over status quo

Estimated cost savings of 1-

5% over status quo


10% over status quo


20% over status quo

Cost savings approximated

to be 21%+ over status quo

Improves cost efficiencies due to enhanced staffing,

processes, equipment usage, chemical usage, fuel usage,

power usage, etc.

Long-Term Financial Impacts Financial Impact Scale -

TOTEX/Estimated Useful

Asset Life

Highest Financial Impact

Value

Lowest Financial Impact

Value

Impacts long-term financial viability.

ENVIRONMENTAL CRITERIA Tier 3 Measure Lowest Rating (0) (0.25) (0.50) (0.75) Highest Rating (1) Definitions:

Regulatory Compliance Compliance Scale Negative Impacts to

Regulatory Compliance

No Impacts to Compliance

Requirements

Indirect positive impacts Direct Positive Impacts to


Direct Impact- Required to

Maintain Regulatory

Compliance

Impacts compliance with Federal, State, local or internal

requirements.

City Sustainability Initiatives Sustainability Scale Negative Impact to

Multiple City Sustainability

Initiatives

Negative Impact to a City

Sustainability Initiative

No Impact to City

Sustainability Initiatives

Positive Impact to a City

Sustainability Initiative

Positive Impact to Multiple

City Sustainability

Initiatives

Impacts alignment with Aurora Water’s sustainability

initiatives.

Environmental Risk Management Environmental Risk

Management Scale

Increases One or More High

Priority Environmental

Risks

No Impact on High Priority

Environmental Risks

Partially or Fully Addresses

One or More High Priority

Environmental Risks

Impacts the management of environmental risks not

covered under Regulatory Compliance

Permitting Requirements Permitting

Requirements Scale

Introduces Multiple

Significant Permitting

Complexities and/or

Requirements

Introduces a Significant

Permitting Complexity

and/or Requirement

Introduces Multiple

Moderate Permitting

Complexities and/or

Requirements

Introduces One Moderate

or Multiple Slight

Permitting Complexities

and/or Requirements

No Permitting Complexities

and/or Requirements

Impacts the management of permitting requirements

and/or complexities

SOCIAL CRITERIA Tier 3 Measure Lowest Rating (0) (0.25) (0.50) (0.75) Highest Rating (1) Definitions:

Levels of Service Core LoS Scale No Impact to Core Service

Levels

Positive Impact to a Core

Service Level

Positive Impact to Multiple

Core Service Levels

Impacts Aurora Water agreed levels of service

Customer Benefit Customer Benefit Scale No Impact to Customers Positive Impacts to 0-500

Customers

Positive Impacts to 501-

10,000 Customers

Positive Impacts to 10,001-

100,000 Customers

Positive Impact to more

than 100,000 Customers

Impacts customer benefits such as public health & safety

System Performance Single system score Lowest Project Rating Highest Project Rating Impacts system reliability, resiliency, and redundancy

Social Benefit Social Benefit Scale Significantly Increases One

or More Social Risks

Increases One or More

Social Risks

No Impact on Social Risks

and/or Benefits

Partially Improves One or

More Social Benefits

Significantly Improves One

or More Social Benefits

Impacts management of social risks/benefits, specifically:

Reputation with peers, customers, constituents and/or

political benefits

Contractual Obligations Compliance Scale Introduces Significant

Contractual Complexity

Introduces Minor

Contractual Complexity

Neither Introduces Nor

Solves Contractual

Issues/Complexity

Addresses Minor

Contractual Requirements

Addresses Significant

Contractual Requirements

Impacts compliance with legal, contractual, regional, and

other requirements that are not covered under


<---------- Linear Distribution ---------->

<---------- Linear Distribution ---------->



The project scoring process utilized to assess projects for the IWMP CIP prioritization was robust

and required participation from a number of project stakeholders. The scoring measures across the

twelve criteria were composed of a mix of qualitative rating scales and two quantitative measures.

Qualitative measures used were designed to differentiate projects at logical progression points based

on stakeholder expertise. For example, the Levels of Service criterion was structured such that the

lowest rating on the scale (0) was assigned to a project that had no impact to Aurora Water’s core

levels of service, 0.50 was assigned to projects that had positive impacts to a single core level of service

while 1 (highest score) was given to projects that had multiple positive impacts to core levels of service

(Table 8-1). To decrease objectivity on some of the qualitative rating scales used, the team also

employed numeric ranges to assess certain criteria.

8.2.3 ADDITIONAL PRIORITIZATION ANALYSES – SCHEDULE OPTIMIZATION

Aurora Water determined that the CIP would be based on project requirements and sequencing

required under Planning Scenario 2 (Fast Growth). This was believed to represent a reasonable

tradeoff between cost and management of uncertain future growth and other risks.

Once IWMP project portfolios were developed for Planning Scenario 2 (Fast Growth) and Aurora

Water was presented the optimization approaches available, the decision to pursue multi-year schedule

optimization was made. A multi-year schedule optimization model was built out in Expert Choice and

used as the primary tool for developing multiple iterations and optimization runs through the

modeling process.

After analyzing and considering the initial optimization outputs and funding scenarios, Aurora Water

management opted to set a maximum annual CIP budget of $39M/year, as this resonated best with

business objectives. As such, further QA/QC and review was conducted, further updates to projects

were incorporated into the portfolio where necessary, and modeling of the revised $39M/year CIP

scenario was performed.

In designing and leveraging this decision framework, MWH and Aurora Water were able to deliver a

prioritization process that accomplished a number of key success targets. In all, this framework and

process included participation from all levels of Aurora Water’s organization, incorporated robust data

development and integration into the modeling and decision support effort and leveraged progressive,

best in class decision methodologies. It provided a background of data and modeling work enabling

better transparency into the decision process while aligning capital planning with Aurora Water

organizational objectives through use of a well-defined decision framework.

8.3 CIP Results

After final revisions and reviews were held, Aurora Water proposed the 10 year CIP presented in

Figure 8-2 through Figure 8-4 and Table 8-2. The final 10 year CIP accounts for a total of $395.9M

in anticipated capital spending. The spend for this CIP is broken down as follows: $213M for Water

Resources projects, $102M for T&D, $30M for Treatment, and $51M for water rights acquisitions

over the 10 year term (Figure 8-2). Excluding water rights acquisitions, the total 10 year CIP amounts

to $344.5M.




Figure 8-2. Aurora Water 10 Year CIP, Total by Discipline


Figure 8-3. Aurora Water 10 Year CIP, Spend by Year

Figure 8-4 presents a summary-level Gantt chart outlining the planned project scheduling over the

10 year CIP term. An allocation to water rights acquisitions is budgeted when the sum of the budgets

for Water Resources, Treatment, and T&D projects do not exceed the targeted $39M threshold per

year. In total, the planned 10 year CIP is very close to the targeted $390M value, only exceeding this

target by $5.9M over the period.

215

104

30

51

$0

$50

$100

$150

$200

$250

$300

$350

$400

$450

Water Resources 10-Yr T&D 10-Yr Treatment 10-Yr Water Rights Acquisitions Total 10-Yr CIP

Mill

ion

s

Aurora Water 10 Year CIP | Total By Discipline

54%

26%

7%

13%

Total =$399.8M

$-

$5

$10

$15

$20

$25

$30

$35

$40

$45

2017 2018 2019 2020 2021 2022 2023 2024 2025 2026

Mill

ion

s

Aurora Water 10 Year CIP | Spend by Year

Water Resources 10-Yr T&D 10-Yr Treatment 10-Yr Water Rights Acquisitions Target Funding Limit



Note: The updated T&D CIP projects from the Refinement Study are not reflected in this figure. See Section 7 for the updated T&D projects.

Figure 8-4. Aurora Water 10 Year CIP Summary Gantt Chart



Table 8-2. Aurora Water 10 Year CIP Cash Flow Summary*

*Note: The updated T&D CIP costs from the Refinement Study are not reflected in this table. See Section 7 for the updated T&D costs

Discipline: 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 Total:

Water Resources 17,252,667$ 17,502,667$ 17,861,228$ 30,893,147$ 38,787,742$ 23,660,406$ 24,978,588$ 20,033,357$ 15,405,535$ 6,838,201$ 213,213,538$

T&D 1,426,500$ 12,745,245$ 6,532,111$ 8,676,265$ 2,092,500$ 13,021,704$ 13,153,000$ 18,623,000$ 11,711,500$ 13,720,000$ 101,701,825$

Treatment -$ -$ -$ -$ -$ -$ -$ 1,730,000$ 13,942,500$ 13,942,500$ 29,615,000$

Water Rights Acquisition20,320,833$ 8,752,088$ 14,606,661$ -$ -$ 2,317,890$ 868,412$ -$ -$ 4,499,299$ 51,365,183$

Total: 39,000,000$ 39,000,000$ 39,000,000$ 39,569,412$ 40,880,242$ 39,000,000$ 39,000,000$ 40,386,357$ 41,059,535$ 39,000,000$ 395,895,547$



9.0 References

AMEC, 2014. Approach for Developing IWMP Hydrology Scenarios, AMEC, October.

Aurora, 2015. 2015 Municipal Water Efficiency Plan, Aurora Water, City of Aurora, Colorado.

BBC Research and Consulting, 2015. Water Demand Forecasts for Integrated Water Master Plan,

prepared for Aurora Water and MWH Global, Inc., February.

CDM, 1997. Water Treatment Master Plan. Camp Dresser & McKee (CDM).

CH2M Hill, 2012. Treated Water Master Plan, CH2M Hill.

CH2M Hill, 2015. Aurora Water Treatment Capacity Capital Improvements Plan Review and Update

(CIP Update), CH2M Hill.

Maddaus Water Management, 2014. Water Conservation Technical Analysis, Technical

Memorandum, prepared for Aurora Water and MWH Global, Inc., December.

MWH, 2014a. Description of Baseline Conditions for Water Resources Modeling, MWH Global, Inc.,

Denver, Colorado, June.

MWH, 2014b. Planning Scenarios for Technical Disciplines, Technical Memorandum, MWH Global,

Inc., Denver, Colorado, October.

MWH, 2014c. Integrated Water Master Plan Risk Framework Report, MWH Global, Inc., Denver,

Colorado.

MWH, 2014d. Integrated Water Master Plan Risk Management Report, MWH Global, Inc., Denver,

Colorado.

MWH, 2014e. Water Resources Risk Vulnerability Technical Report, MWH Global, Inc., Denver,

Colorado. December.

MWH, 2015. Draft Water Needs Assessment Technical Report, MWH Global, Inc., Denver,

Colorado. March.

MWH, 2016a. Draft Water Resources Project Technical Report, MWH Global, Inc., Denver,

Colorado. March.



MWH, 2016b. Draft Water Resources Project Portfolios, MWH Global, Inc., Denver, Colorado.

April.

MWH, 2016c. Aurora Watershed Management and Source Water Protection Plan, MWH Global, Inc.,

Denver, Colorado, April.

MWH, 2016d. 2070 Gap Analysis, Technical Memorandum, MWH Global, Inc., Denver, Colorado.

April.

MWH, 2016e. Transmission and Distribution, MWH Global, Inc., Denver, Colorado. April.

MWH, 2016f. Aurora Integrated Water Master Plan, MWH Global, Inc., Denver, Colorado. May 4.

MWH, 2016g. Integrated Water Master Plan Draft Report, MWH Global, Inc., Denver, Colorado.

May.

Documents

Integrated Water Master Plan - Aurora, Colorado · The Integrated Water Master Plan (IWMP) integrates short-term and long-range planning across the Water Resources, Treatment, and