Laserfiche WebLink
<br />Water Supply Reserve Account - Grant Application Form <br /> <br />Form Revised October 2006 <br /> <br />3. Please provide an overview of water project or activity to be funded including - type of activity, statement of what <br />the activity is intended to accomplish, the need for the activity, the problems and opportunities to be addressed, <br />expectations of the participants, why the activity is important, the service area or geographic location, and any <br />relevant issues etc. Please include any relevant Tabor issues. Please refer to Part 2 of criteria and guidance <br />document for additional detail on information to include. Attach additional sheets as needed. <br /> <br />This project involves direct determination of crop water use by using a weighing lysimeter. The weighing lysimeter <br />facility was funded by the Colorado Water Conservation Board and constructed at the Arkansas Valley Research <br />Center, Rocky Ford. As described below, the Penman-Monteith equation uses detailed electronic weather station data <br />to compute evapotranspiration (ET) of a standardized, hypothetical reference crop. This project will support the <br />collection ofET and meteorological data from the recently installed weighing lysimeter at the Arkansas Valley <br />Research Center. Subsequently this project will provide data required to address consumptive use issues inherent in <br />the Colorado-Kansas lawsuit. <br /> <br />The following was developed by Tom Ley as a background document for requesting funding for a lysimeter facility at <br />the A VRC (Ley, 2004). <br />"In the Fourth Report in Kansas v. Colorado, No. 105, Original (U.S. Supreme Court), Special Master Arthur <br />Littleworth recommended the ASCE Standardized Penman-Monteith equation be used for determination of crop <br />consumptive use in the H-I Model (which is used to determine depletions to usable Stateline Arkansas River flows <br />and subsequently Arkansas River Compact compliance). The ASCE Standardized Penman-Monteith equation uses <br />detailed electronic weather station data to compute evapotranspiration (ET) of a standardized, hypothetical reference <br />crop. In this case, the reference crop is alfalfa. Crop evapotranspiration (consumptive use) is then computed using <br />crop coefficients, which relate the water use of specific crops to the hypothetical alfalfa reference crop ET as the <br />crops grow and mature through the season. A daily time step is used from which monthly crop ET is computed. <br /> <br />To obtain the most accurate estimates of crop evapotranspiration in the Arkansas Valley of Colorado (as well as <br />throughout the State) using the ASCE standardized Penman-Monteith methodology, two issues must be addressed: <br />1. The performance and predictive accuracy of this method for computing alfalfa reference crop ET must be evaluated <br />for the growing conditions in southeastern Colorado, and, <br /> <br />2. Crop coefficients for the various crops grown in the Arkansas River Valley must be determined for both well- <br />watered conditions and the typical local growing conditions; and specifically for the ASCE standardized Penman- <br />Monteith equation (as opposed to relying on adjusted crop coefficients developed for other ET equations in other <br />locations) . <br /> <br />ET of an alfalfa reference crop and ET of various crops of interest can be measured directly through carefully <br />controlled use ofa weighing lysimeter. Depending on the design of the lysimeter, ET can be measured: a) in time step <br />increments ranging from 15-60 minutes to daily and longer periods, b) under various environmental crop stresses as <br />might be caused by water shortage, poor water quality, and/or high water table conditions." <br /> <br />4 <br />