Laserfiche WebLink
8.3 Compact- Constrained Data Set and Modeling Methods - Based on the approach <br />developed in Subtask 8.2 and the work conducted in Tasks 6 and 7, prepare data and <br />model methods quantify water availability to Colorado. The cost estimate assumes that <br />the current Riverware implementation of the CRSS model will be used for the basin -wide <br />analyses, with simplified approaches to representing curtailments to the Upper Basin as a <br />whole. Rather than modify the CRSS model to implement terms of the Upper Colorado <br />River Basin Compact, the water availability results from the CRSS model will be post - <br />processed to determine curtailments to Colorado. The cost estimate also assumes that the <br />same hydrology model, methods, and sequences used in the intra -state (StateMod) <br />analyses and developed in Subtask 7.9 will be used to generate inflow ensembles to the <br />basin -wide model. Finally, the cost estimate assumes that depletion estimates within <br />Colorado will be estimated for a given flow ensemble based on the total consumptive use <br />calculated by the StateMod models, and the relationship between that detailed estimate of <br />depletions and the nominal level of depletions normally used in CRSS will be used to <br />adjust depletions in other Upper Basin states to more realistically reflect depletions <br />during dry spells. <br />The consulting team will modify the method set out in Task Memorandum 8.2 and <br />Task 8.4 to include the use of two values to bound the 10 -year cumulative flow <br />requirement of the Colorado River Compact and the 10 -year cumulative amount of <br />the Upper Basin's share of the Mexico delivery obligation. These values will be 75 <br />million acre -feet and 82.5 million acre -feet. <br />8.4 Generation of Curtailment Amounts - Using the approach and methods developed in <br />Subtasks 8.2 and 8.3, generate ensembles of curtailment amounts. Use the modeling tool <br />to create time - series traces of curtailment that correspond to each flow ensemble member <br />in the alternate and climate change hydrology data sets developed in Subtask 7.9. <br />8.5 Characterize Compact- Constrained Historical and Alternate Hydrology - Develop a <br />summary spreadsheet of the results of the basin -wide water availability analysis, <br />including a comparison the historical hydrology, the extended historical hydrology and <br />the climate change hydrology. Characterize statistics of water availability based on the <br />different hydrology data sets to illustrate the impact of the assumption of alternate <br />hydrology on the legal availability of water to the State of Colorado under the Colorado <br />River Compact and the Upper Colorado River Basin Compact. <br />8.6 Summarize Compact Effects - Prepare a draft memorandum describing the methods, <br />analysis and results of the basin -wide water availability analysis. Cost estimate assumes <br />one review cycle with the CWCB staff and State legal counsel, or others able to provide <br />input on the legal significance on the approach. <br />Colorado River Water Availability Study Scope 31 <br />Exhibit A1.doc <br />12/15/2009 <br />