1. Colorado River Simulation System (CRSS) Salinity Projection Model October 20, 2004 Colorado River Basin Salinity Control Advisory Council

2. Issues Addressed The model did not accurately simulate the historical period 1971-1990 Problems Identified: –Changing natural flow and salt mass relationship –Input data inconsistent –Limited and out-of-date documentation

4. Our Solutions Develop a new natural salt model Re-compute natural flow 1971-2000 Direct new research to better understand salt loading resulting from irrigating agriculture Complete peer reviews with journal articles and supporting documentation Prepare to move model input data to a secure database Involve States during entire process

7. Peer Reviews Article describing new salt model accepted in a peer reviewed scientific journal ( ASCE Journal of Environmental Engineering) 1971-1995 CU&L data reviewed and revised by UC Regional office Methods to distribute CU&L for computation of natural flow reviewed by UC Regional office Methods to compute natural flow and salt reviewed by UC/LC modeling team CRSS Salinity Projection model reviewed by the UC/LC modeling team

8. Publications “Statistical Nonparametric Model for Natural Salt Estimation,” ASCE Journal of Environmental Engineering, to be published January 2005. “Draft Upper Basin Consumptive Uses and Losses Report as Revised After Peer Review 1971-1995.” “Upper Colorado River Consumptive Use Determination at CRSS Natural Flow Node Locations CY 1971-1995.” “Natural Flow And Salt Computation Methods 1971-1995”

9. Concluding Remarks Reclamation has a working model that we have confidence in and can support New salt model can easily be updated New methods and data in CRSS Salinity Projection Model fully supported with documentation Reclamation has begun reviewing CRSS Salinity Projection Model runs with Salinity Forum TMS Future research targeted to address upcoming issues

10. Colorado River Simulation System (CRSS) Salinity Projection Model For further information: http://cadswes.colorado.edu/~prairie