Risk Study - Phase 

  

Status Report for

 
 

Colorado River District

 
 

Boo rd of Directors

  


Phase Scope of work

9
Current and Future Conditions Modeling in Both CRSS and StateMod
Current 2018 Demand schedule from UCRC StateMod?s baseline

Future Demands Define first for StateMod, then with CRSS

Investigate StateMod behavior with respect to admin and adiudication dates:
Uncertainty about ?pre? vs ?post" compact water volumes

Within and across west-slope basins

Using several different administration dates

PRELIMINARYM



 

 






I, How Much Consumptive Use is Senior to Key Dates in Development of
Colorado Water?

Modeled Administration dates:

(12/31 899) turn of the Twentieth Century (as a ?bookend?)
(1 24/ 922) the signing of the Colorado River Compact

{.944 - 
1:33.

25/ 929) the signing of the Boulder Canyon Proiect Act






gafter the Fryingpan-Arkansas Proi?ct administration date 

 

 PRELIMINARYM

 

           

All Colorado River Depletions within Colorado 

2,500,000 - - - - 2,305,968
2,303,396
2,000,000 
1 738 931
~25; 1,649,573 1,661,774 1 713,873
5 1,531,946 15583833
'5 1,500,000 1 
1,181,909
0
a 973,422
2 1,000,000 
5
3?6
2
500,000


 



12/31/1899 11/24/1922 6/25/1929 7/31/1935 7/30/1957

 

I Appropriation Date I Administration Number

 

   

 

 FT


Note the simulated pre-compact consumptive use numbers 


higher than we expected (conventional wisdom based on Historical usage suggests ~l .l -l .2 MAF)

 

All Colorado River Depletions within Colorado

2500-000 2,305,968
2,303,396

 



  

1,138,931
,774 1 713,873

1,558,833

  
 
   

1,649,573

  


1,181,909
973,422

  

1,000,000

Average Annual Depletion: (AF/yr)


12/31/1899 11/24/1922 6/25/1929 7/31/1935 7/30/1957

I Appropriation Date I Administration Number

 

 

 

   

 Why? I FT





Increased irrigation efficiency if only using pre-l 922 rights
Typically there is water available for both SR and JR rights, so modeled efficiency is lower (this is also
reflected in actual usage data)
Better methodologies for determining Crop CU over time

Modified B-C including High-Alt adiustments lead to higher CU than previously computed

 

All Colorado River Depletions within Colorado

2500900 2,305,968
2,303,396

  

1%


    
  
   

1,738,931
.774 1 713,873

1,558,833

1,649,573

  

2%
5

1,181,909
973,422

  

1,000,000 

Average Annual Depletion: (AF/yr)

 

 

12/31/1899 11/24/ 1922 6/25/1929 7/31/1935 7/30/1957

I Appropriation Date I Admhistration Number

   

 

 . 


Digging into the details of the Statemod model

Baseline individual basin .StateMod vs CRSS

Baseline linked StateMod 'vs Baseline individual basin StateMod

 

 


- lnduvnduol Bosm S?ro?reMod CRSS Comparison 

SloleMod and CRSS results from 1 988-2005 (current period of overlap when using the
?Stress Test? hydrology)
CRSS SloteMod
CRSS-BL (current) Annual Depletions (AF/yr) StateMod IndIVIdual Annual Depletions (AF/yr)
Minimum Average Maximum (current) Minimum Average Maximum
Yampa 169,151 193,879 209,249 Yampa 173,547 196,982 215,193
White 22,884 36,624 48,310 White 48,550 62,060 69,030
Upper Colorado Upper Colorado 
Front Range 684,794 1,227,709 1,294,957 Front Range 1,117,487 1,220,386 1,345,192
Gunnison 269,198 501,108 532,688 Gunnison 502,591 575,267 624,538
San Juan Dolores 224,687 410,644 438,421 San Juan Dolores 335,365 500,717 556,627 
StateWide 1,370,713 2,369,965 2,523,625 StateWide 2,258,518 3 2,743,484





x/

2,250,560



Linked StateMod vs Individual Basin StateMod Results 





- 1988-2005

Average Depletions Are Similar 1% Diff)

Upper Colorado model from CRWAS, not 2015 update

Individual Basin Models 
Average Average
Individual Model Average CU Average EvapAverege loss Depleliens Linked Model Average cu Average Evap Average Loss Deplelions
Basin (AF/yr) (AF/yr) (AF/yr) (AF/yr) Basin (AF/yr) (AF/yr) (AF/yr) (AF/yr)
Yampa 170.538 12.870 13.573 196,982 Yampa 169,354 11,383 13,147 193,884
While 49,758 3.086 9.217 62.060 whale 49,750 1,767 9,216 60,733
Colorado 1,117,645 48,414 54,327 1220.386 Colorado 1,108,453 45,157 52,867 1,206,476
Gunnison 487,856 37,715 49,697 575,267 Gunnison 489,354 34,674 49,241 573,269
San Juan 424,764 33,600 42,353 500,717 san Juan 417,240 29,747 42,776 489,763/
. rolol Individual 135,685 169,167 2,555,413 Total linked 2.234.151 122.728 167.246 

2,524,127









Shortages are apparent both to new uses as well as some iunior existing uses (Especially on the

Colorado mainstem)

Equivalent increases used for other Upper Basin states in CRSS (equivalent to approximately 2040

StateMod Future Uses

Future Uses identified through conversations with BRT reps on the Technical Working Group

in the 2017 UCRC Demand Schedule)



 

 

 

 

 

 

 

 

 

 

 

 

 

Future Use Depletions (AF/yr)
StateMod Average Yield of Average Increase Input Demand
Linked Model New Depletions in Basin Depletions

Yampa 29,506 29,485 30,104
White 61,839 61,787 65,000
Upper C?l?rad? 86,077 82,425 120,450
Front Range
Gunnison 31,053 31,100 37,900
Southwest 81,104 82,355 130,499
a: ?f21 .3: 2?StateWide 289,578 287,153 383,953

 

 





 



Preliminary Results

Simulating Lake Powell conditions with linked StateMod/CRSS model
Baseline 2019 Current conditions demands
Future ~2040 (UT, WY, New demands for StateMod (+384kaf)

Stress Test (1988-2015) Hydrology

FT



 

 

3,750.0 77?~ - - . 

 

 

 

Powell Pool Elovetlon (ft)



 

?Soen 1: Baseline, Current Seen 2: Baseline, Future ?Soen 3: DCP, Current

   

?Saen 4: DCP, Future

 

 

 . PRELIMINARYM

a What?s Next? 

Continue To Look at Pre-Compact CU Estimates

Simulate Different Call Demand Management Scenarios in StateMod

Simulate Stress Test in CRSS With Current StateMod Depletions

incorporate Future Depletions Into CRSS

 

 

 

ED