Development, Technical

Basis, Operation and

Implementation of

the Lease Fallowing Tool

Ralph (Terry) Scanga

Upper Arkansas Water Con. Dist.

Ivan Walter, P.E.

Ivan’s Engineering/UAWCD

Dr. Timothy Gates

Colorado State University

Kelley Thompson, P.E.

CO Division of Water Resources

Project Sponsors

• Colorado Water Conservation Board

• Arkansas Basin Roundtable

• Upper Arkansas Water Conservancy District

• Southeastern Colorado Water Conservancy District

• Lower Arkansas Valley Water Conservancy District

• Board of Water Works Pueblo

• Colorado Springs Utilities

Project Co-Sponsors

CWCB Water Projects

• Alternative Agricultural Water Transfer Methods –Projects that provide usable and

transferable information that will increase our understanding of how to successfully design transfer programs that provide a long-term, reliable water supply while sustaining meaningful agricultural production

Ark. River Basin Roundtable

• Basin Implementation Plan – If water is going to be transferred from

agriculture, how can it be done right

– Funding for Rotational Fallowing • Approved alternative agriculture transfer method

– Three Tracks are being pursued

• Technical Studies

• Policy Studies

• Pilot Projects

LFT Project Team

• Colorado State Univ. Civil Engr. Dept – Dr. Tim Gates – Dr. Ryan Bailey – Cale Mages

• Division of Water Resources

– Kelley Thompson, P.E.

• Upper Ark. Water Conservancy Dist.

– Ivan A. Walter, P.E.

LFT Technical Committee

• Professionals familiar with and experienced in water right transfers in Colorado

• Provide review and feedback to the Project Team

LFT Technical Committee

• Dept. of Natural Resources

– Bill Tyner – Asst. Division 2 Engineer

– Andy Moore – CWCB Senior Wtr. Res. Engr.

• Municipal & Conservancy Districts

– Alan Ward -- BWWP

– Tom Simpson – Aurora

– Bob Hamilton – SECWCD

– Jack Goble – LAVWCD

LFT Technical Committee

• Engineering Consultants

–Ivan A. Walter, P.E.

–Tom Williamsen, P.E.

–Mark McLean, P.E.

–Randy Hendrix, P.E.

–Daniel Niemela, P.G.

Purpose of the Project

• Development of an accepted basin-wide preferred methodology – common platform – that can be a state-wide template for temporary water transfers under lease fallowing – Create a general accepted, common technical

platform for determination of consumptive use and return flow impacts

– Reduction of transactional costs of temporary transfers

Scope of the Project

• Phase 1: Define Basic Data Requirements for Accounting Tool

• Phase 2: Develop and Evaluate Accounting Tool - Farm Headgate Diversion, Crop ET, Surface Runoff & Recharge to Aquifer.

• Phase 3: Develop and Evaluate Accounting Tool -- Alluvial Aquifer Response

• Phase 4: Document Accounting Tool and Prepare Guidelines for Use

Implementation of the L.F. Tool

• HB 13-1248

– CWCB authorized to administer a pilot program to test the efficacy of fallowing-leasing as an alternative to permanent agricultural dry-up.

– SEO charged to establish criteria and guidelines for the application, selection, and approval process for pilot projects

Implementation of the L.F. Tool

• Guidelines and Criteria for Pilots Project

– Proposed pilot projects shall be evaluated with the Lease Fallowing Tool

• Catlin Pilot Project -- 2015 operation

Major

Processes

in an

Irrigated

Stream-

Aquifer

System

ISAM URF

LFT Technical Basis

• Evaluates historical use of irrigation water and return flows from parcel crop irrigation.

• Uses Irrigation System Analysis Model (ISAM) soil moisture budget / water balance routine

• ISAM based on consumptive use subroutine of Hydrologic Institutional (H-I) Model

• ISAM models several processes differently/ more conservatively than StateCU model

• A unit response function (URF) may be supplied to determine historical accretions to the stream

General Root Zone Soil Moisture Budget

P

ET

RO

ΔΔ

DP

I

RootZone

ΔS

Deep Percolation / Recharge to GW

Surface Runoff/Tailwater

Crop Irrigation Water Requirement Met by Irrigation Water

ISAM Water Balance Schematic

URF Stream Depletion % of the Change in Recharge

Computed by Analytical or Numerical Model

URF Stream Depletion % of the Change in Recharge

ISAM LFT Database

Deep Percolation / Subsurface Return Flow Amounts

LFT reads available data

MATLAB Code

Microsoft Excel Spreadsheet

GUI

• Crop ET • Soil properties • Irrigation efficiencies • Diversion data

User Data Input or Edit

• Climate data

• User controls analysis • User can import data

from database, paste in data, and modify before calculations performed

• Optional: space to enter monthly URF values to calculate return flows to the river network

Data grouped based on Colorado water division URFs Stream Depletion/Accretion

MATLAB code reads input data in Excel

MATLAB code writes output into Excel

Excel spreadsheet interface where user

enters and modifies input data, controls analysis, and can view modeling results

Execution engine

LFT Files

Extract to C:\LFT\application etc.

Spreadsheet input/output Users Manual batch (auto copy/improve exec) Database files

Execution Engine

• Controls input and output and execution

• Must enable macros to run LFT

• Filename Page - defines where LFT .exe located

– After set then can renamed/copy/move anywhere

• Parcel Page – Enter parcels and scenarios

– four main sections

parcel control input data analysis & output links

• LFT produces upto three worksheets per parcel

1)Input (P_data) 2)Results (P_R) 3)Summary (P_S)

LFT Excel spreadsheet

LFT Model Data

• Model data supplied by LFT and/or by User

• LFT data is supplied to streamline evaluations

– From CDSS Hydrobase/StateCU models & H-I Model

• LFT data

– Climate based (PET, precip., opt. winter demand)

– Ditch based data (Diversions, shares/ac, crop dist.)

– Ditch parameters (Canal losses, app eff, AWC, etc)

• User must supply

– Acres of flood, sprinkler, or drip irrigation

– Ditch shares (or defaults to acreage proration)

• User can modify or cut/paste all data directly in Excel or also import files (xls based)

Areas with LFT Data (as of 2/2016)

LFT Climate Based Data • Crop PET • Precipitation (total) • Wintertime Demand (optional/k=0.2)

Supplied PET Datasets:

• MBCTR21 / HB1248 Basinwide at primary NOAA stations (DSS StateCU Modified Blaney Criddle with TR21 crop coeff.) - Div 1,2&3

• DSS Basinwide at NOAA stations (DSS StateCU MBC with calibrated coefficients) - Div 3

• HIM for H-I Model ditches and CoAgMet stations (ASCE PM / Calibrated MBC Approved by KS) - Div 2

LFT Ditch Based Data

Ditch Diversions (user must ensure diversion data are appropriate)

• Div 1&3 – from DSS models • Div 2 – from Hydrobase

water class aggregation

Ditch Shares • Div 1&3 – na • Div 2 – ISAM

Ditch Acres • Div 1&3 – DSS • Div 2 – HIM

Crop Distributions • Div 1&3 – DSS models • Div 2 – H-I Model

Extent: Div 1&3 – Basinwide / Div2 – H-I Model Area

LFT Ditch Parameter Data

• Canal Loss

• Application Efficiency*

• Lateral Loss* (on/off farm)

• Spray Loss*

• AWC*

• Rooting Depth*

• Div 1&3 – DSS Models

• Div 2 – HIM Model

* Parameters defined by HB13-1248 Criteria and Guidelines if select HB1248 dataset

Extent: Div 1&3 – Basinwide / Div2 – H-I Model Area

LFT Supplied Data

• Modeling sets used to build LFT data available through DWR webpage (“Previous Versions” link)

• Work ongoing to expand/improve data

– next task - CoAgMet station datasets.

• LFT databases will be updated annually

• LFT data can updated using LFT via internet

– Continued vision for direct connect to Hydrobase

• User will be informed through update button if LFT version needs to be updated

Lease Fallow Tool - where to get it • CWCB website – cwcb.state.co.us

click on Technical Resources – http://cwcb.state.co.us/water-management/water-

projects-programs/Pages/LeaseFallowTool.aspx

• CDSS website – cdss.state.co.us click on Software Products – http://cdss.state.co.us/software/Pages/

LeaseFallowTool.aspx

• DWR website – water.state.co.us click on Data&Maps-Modeling/CDSS – http://water.state.co.us/

DataMaps/ModelingCDSS/Pages/LeaseFallowTool.aspx

CWCB website – cwcb.state.co.us

CDSS website – cdss.state.co.us

DWR website – water.state.co.us

LFT install – needs 2 things

from web page…

Please refer to the User’s Manual to install the LFT. An install file is available to

install the LFT along with the prerequisite Matlab R2014a MCR on Windows 32

and 64bit computers. However, if the MCR or a previous version of the LFT has

already been installed, it is recommended to download a zip of the most current

LFT files and copy new files into the LFT folder. The LFT and files will be

updated periodically.

Links: Install 32bit / Install 64bit / Files 32bit / Files 64bit / Previous Versions

Important Note: Although the MCR should be installed to its default location,

the LFT itself should NOT be installed within the “Program Files” folder

(recommended C:/LFT, etc.)

Matlab MCR – free library that allows execution of compiled Matlab Code without Matlab - installed to: Program Files

LFT files – executable (.exe), database files (.mat), etc. - NOT installed to Program Files - can be copied without install to C:/LFT/application, etc.

User Manual & Hydrologic Reference Notes

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est

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