1

Chesapeake Bay ProgramWatershed Modeling

Gary Shenk, Lewis Linker, Rich BatiukPresentation to STAC

3/22/2011

2

Chesapeake Bay Partnership Models

3

Recent History of theChesapeake Bay Program’s

Watershed Model

• Phase 4.3 – (2002 – 2010) - C2K• Phase 5.3.0 – (2010) – TMDL

– Segmentation Input data– Calibration Functionality– Accessability

• Phase 5.3.2 – (2011-2017) – WIP2– Land use– Nutrient Management

4

Watershed Model Supervision

• Water Quality Goal Implementation Team– Watershed Technical Workgroup– Agriculture Workgroup– Urban Stormwater Workgroup– Forestry Workgroup– Sediment Workgroup

• Modeling Workgroup (STAR)• PSC

5

STAC involvement in WSM

• Formal review in 2005 and 2008 of watershed model

• Workshops in the past 10 years– Modeling in the CBP: 2010 and beyond– Pasture Management– Atmospheric Deposition– Wetlands– Fertilizer Sales Data– Shoreline Modification– Innovative Ag BMPs

66

Annual or Monthly:

Land Use AcreageBMPsFertilizerManureAtmospheric DepositionPoint SourcesSeptic Loads

Hourly Values:

RainfallSnowfallTemperatureEvapotranspirationWindSolar RadiationDewpointCloud Cover

Daily output comparedTo observations

How the Watershed Model Works

HSPF

77

Each segment consists of 30 separately-modeled land uses:

• Regulated Pervious Urban• Regulated Impervious Urban• Unregulated Pervious Urban• Unregulated Impervious Urban• Construction• Extractive • Combined Sewer System• Wooded / Open• Disturbed Forest

• Corn/Soy/Wheat rotation (high till)

• Corn/Soy/Wheat rotation (low till)

• Other Row Crops• Alfalfa• Nursery• Pasture• Degraded Riparian Pasture• Afo / Cafo• Fertilized Hay • Unfertilized Hay

– Nutrient management versions of the above

Plus: Point Source andSeptic Loads, and

Atmospheric Deposition Loads Each calibrated to nutrient and

Sediment targets

How the Watershed Model Works

8

Precipitation FertilizerManureAtmospheric deposition

Runoff

How the Watershed Model Works

Hydrologysubmodel

Management filter

RiverSedimentsubmodel Phosphorus

submodel

Nitrogensubmodel

hourly

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Automated Calibration

CalibrationProcedures

Input DataScenario Builder

CalibrationData

10

Calibration Strategy

• Match observations in rivers• Match properties and trends

– Groundwater recession curve– Crop uptake of Nitrogen

• Match literature and other models– Reasonable rates of nutrient export– USGS estimator and sparrow empirical

models

10

1111Automated Calibration

12

Log of WSM and Estimator TN Loads

5

5.5

6

6.5

7

7.5

8

8.5

5 5.5 6 6.5 7 7.5 8 8.5Estimator (pounds per year)

WS

M p

5.2

(pou

nds

per

year

)

wsm p5.3wsm p5.3 PQUALwsm p5.21:1

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Correlation of Fall Line Stations vs Estimator Annual Loads TN

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Sus

queh

anna

Pat

uxen

t

Pot

omac

Rap

paha

nnoc

k

Mat

tapo

ni

Pam

unke

y

Jam

es

App

omat

tox

Cho

ptan

k

Mod

el e

ffic

ienc

y

wsm p5.3wsm p5.3 PQUALwsm p5.2

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'Unbiased' USGS samples vs WSM Population TN p5.3

0.1

1

10JL

7_68

00_7

070

JL7_

7100

_703

0

JA5_

7480

_000

1

YM

4_66

20_0

003

YP

4_67

20_6

750

RU

5_60

30_0

001

PS

2_67

30_6

660

SW

7_16

40_0

003

SU

7_08

50_0

730

SU

8_16

10_1

530

PS

5_52

40_5

200

SL9

_249

0_25

20

SL9

_272

0_00

01

PM

7_48

20_0

001

SJ6

_213

0_00

03

EM

2_39

80_0

001

PS

3_51

00_5

080

PM

2_28

60_3

040

XU

3_46

50_0

001

PM

4_40

40_0

003

PU

3_32

90_3

390

PU

2_30

90_4

050

SL3

_242

0_27

00

TN c

once

ntra

tion

(mg/

l)

WSM 10WSM 25WSM 50WSM 75WSM 90GS 10GS 25GS 50GS 75GS 90

15

Calibration vs validation KS statistic Nitrogen - AGCHEM

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1calibration

valid

atio

n

Validation Better

Calibration Better

161616

Snapshot:

Land Use AcreageBMPsFertilizerManureAtmospheric DepositionPoint SourcesSeptic Loads

Hourly Values:

RainfallSnowfallTemperatureEvapotranspirationWindSolar RadiationDewpointCloud Cover

“Average AnnualFlow-Adjusted Loads”

Quick Overview of Watershed Model Scenarios

Hourly output is summed over 10 years of hydrology to compare against other management scenarios

HSPF1991-2000

ScenarioBuilder

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Number of Scenarios

• Mid 1980s – 0• Early 1990s – phase 2 – fewer than 10• Late 1990s phase 4.1 – 37• Early 2000s – phase 4.3 – 400-500• 2009-2010 – phase 5.3.0 more than 300• 2011 - 2017 - phase 5.3.2 - ?????

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Scenario Builder

Input processor for the watershed model

Generates past, present, or future state of the

watershed

Land use, management practices, fertilizer and

manure applications, crop growth

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Sample Input and Output

Inputs• BMP

implementation

• Remote Sensing • Crop acreage

• Crop yield• Animal numbers

Outputs• BMP

implementation on phase 5 scale

• Land use

• Crop Uptake• Fertilizer• Manure

Parameters• BMP effects on

land use

• Tillage Type

• Plant and harvest dates

• Nutrient application by crop type

• Animal manure nutrient content

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Agriculture40%

Forest15%

Atmospheric Deposition to Non-

Tidal Water1%

Urban & Suburban Runoff18%

Municipal & Industrial

Wastewater21%

Septic5%

Agriculture - manure19%

Agriculture - chemical fertilizer

16%

Agriculture - Atmospheric Deposition - livestock & fertilized soil

emissions6%

Atmospheric Deposition - mobile (on-road + non-

road) + utilities + industries

21%

Natural - lightning + forest soils

1%

Urban & Suburban Runoff - chemical

fertilizer11%

Municipal & Industrial Wastewater

21%

Septic5%

Land Use Source

Ultimate SourceWSM Uses:

Divide Load into contributing areas and sources

212120.7 18.9 18.8 18.2 17.8 17.1 16.8 16.8 16.5 13.6

120.0 114.7 109.8 109.2 108.4 106.6 105.7 104.4 103.9 102.8

71.4 71.9

8.25.0

3.5 3.6 4.1 3.5 2.9 2.9 2.9 3.5

2.4 2.4

81.1

59.158.1 56.7 57.7 56.9 56.2 53.7 53.2 54.8

37.1 37.3

7.5

7.77.3 7.1 6.8 6.6 6.6 6.7 6.7 6.6

4.8 4.7

90.5

79.078.4 77.8 75.4 74.4 73.1 73.9 73.8 71.9

52.1 51.4

5.9

5.55.1 5.0 4.9 4.9 4.8 4.6 4.6 4.5

3.0 2.9

175

17 130

50

100

150

200

250

300

350

400

1985 2000 2001 2002 2003 2004 2005 2006 2007 2008 Strategy StateCap

Goal

mill

ion

lbs.

/yea

r

NY PA DC MD WV VA DE

Nitrogen Loads Delivered to the Chesapeake Bay By Jurisdiction Point source loads reflect measured discharges while

nonpoint source loads are based on an average-hydrology year

333.9

289.9 281.1270.2

175

266.3277.7 275.1

262.9 261.9 260.7

184.4 183.1

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• BMPs that alter nutrient applications to croplando Diet and feed changeso Manure transporto Nutrient management applications

• BMPs involving landuse conversions

• BMPs with nutrient and sediment reduction efficiencies

• BMPs with both landuse conversions and reduction efficiencies

o Riparian forest buffers and wetland restorationo Riparian grass buffers

How is the Bay Watershed Model Applies Practices and Programs

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Agricultural BMPs Developed Lands BMPsRiparian Forest Buffers Riparian Forest Buffers

Riparian Grass Buffers Riparian Grass Buffers

Wetland Restoration Wetland Restoration

Land Retirement Tree Planting

Tree Planting Forest Conservation

Conservation-Tillage Urban Growth Reduction

Continuous No-Till Wet Ponds & Wetlands

Carbon Sequestration/Alternative Crops Dry Detention Ponds & Hydrodynamic Structures

Poultry and Swine Phytase Dry Extended Detention Ponds

Poultry Litter Transport Infiltration Practices

Ammonia Emission Reductions Filtering Practices

Animal Waste Management Systems: Livestock & Poultry Stream Restoration

Barnyard Runoff Control/Loafing Lot Management Erosion & Sediment Control

Dairy Precision Feeding /and Forage Management Nutrient Management

Nutrient Management Applications Abandoned Mine Reclamation

Precision Agriculture Dirt & Gravel Road Erosion & Sediment Control

Enhanced Nutrient Management Street Sweeping

Conservation Plans/SCWQP Septic Connections

Cover Crops (Early- and Late-Planting) Septic Pumping

Small Grain Enhancement (Early- and Late-Planting) Septic Denitrification

Off-Stream Watering with and without Fencing Structural Shoreline Erosion Control

Off-Stream Watering w/ Fencing & Rotational Grazing Non-Structural Shoreline Erosion Control

Precision Grazing

Horse Pasture Management Forestry BMPsWater Control Structures Forest Harvesting Practices

Stream Restoration

Non-Point Source Practices and Programs

http://archive.chesapeakebay.net/pubs/NPS_BMP_Table1.8.pdf (8 pages)

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Process for new BMPs

• Generate request from Sector Workgroup• Convene a review panel

– Gather research– Characterize as to applicability, location,

variability, amount of research, and scientific support

• Review by Source Sector Workgroup, Watershed Technical Workgroup, and WQGIT

http://archive.chesapeakebay.net/pubs/Nutrient-Sediment_Control_Review_Protocol.pdf

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0

5

10

15

20

25

30

35

40

45

1985 Base 2009 Target Tributary Loading Loading Loading E3 All

Scenario Calibration Scenario Load A Strategy Scenario Scenario Scenario Scenario Forest

342TN 309TN 248TN 200TN 191TN 190TN 179TN 170TN 141TN 58TN

24.1TP 19.5TP 16.6TP 15.0TP 14.4TP 12.7TP 12.0TP 11.3TP 8.5TP 4.4TP

Num

ber o

f Seg

men

ts in

DO

Vio

latio

n

Open Water Violations

Deep Water Violations

Deep Channel Violations

Dissolved Oxygen Criteria Attainment

Basin-wide load is190 N and 12.7 P (MPY)

2626

Relative Effect of a Pound of Pollution on Bay Water Quality

2727

Relative effectiveness (Riverine * Estuarine Delivery)

0

1

2

3

4

5

6

7

8

UpES

, MD

UpES

, DE

Mid

ES, M

DSu

sq, M

DLo

wES

, MD

Wsh

, MD

UpES

, PA

Low

ES, D

ESu

sq, P

APx

tB, M

DEs

hVA,

VA

PotB

, DC

Mid

ES, D

EPo

tA, D

CPo

tB, M

DPo

tB, V

ASu

sq, N

YRa

pB, V

APo

tA, M

DYr

kB, V

APo

tA, V

AW

sh, P

APo

tA, W

VPo

tA, P

APx

tA, M

DJm

sB, V

ARa

pA, V

AYr

kA, V

AJm

sA, V

AJm

sA, W

V

Major River Basin by Jurisdiction Relative Impact on Bay Water Quality

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Nitrogen -- Phase 5.3 -- Goal=190

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 1 2 3 4 5 6 7 8 9 10Relative Effectiveness

Perc

ent r

educ

tion

from

201

0 no

BM

Ps to

E3

All OtherWWTP

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Pollution Diet by River

Pollution Diet by State

30

Jurisdictions’ Watershed

Implementation Plans

92 Individual TMDLs

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System Configuration and Flows

BayTAS(In CBPO IT

Infrastructure)

Back-end – BayTAS O&M Team and State

Access (QA, data entry, review etc.)

Final TMDL, Baseline Progress,

Other data.

Feds, States and DC submit Non-Point Source

Load, Practices/Verification using NEIEN

Watershed Model runs measure loadings progress.

To Chesapeake Stat for Presentation31

Wastewater Point Source /Data Direct

Reporting

Scenario Builder

Practices