BOARD02469

• Board Meeting Date: 7/18/2005
• Description: CWCB Director's Report
• Board Meetings - Doc Type: Memo

Colorado Statewide Snowpack

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Staff is also working on linking snowpack information to streamflow information. A
GIS project is currently underway to delineate subbasins within the major river basins.
The maps of subbasins will include SNOTELs , major streams, stream gages, county
and municipality boundaries, all shown on the same maps. The most time-consuming
part of that project so far has been the delineation of sub-basins, but the expectation is
that in late May and early June the project will have progressed sufficiently to allow
users to see quickly where the highest snowpack is, where the stream systems and
communities are downstream of that snowpack, and where the stream gages are located
that would allow measurement of that melted snow once it becomes runoff. A pilot
demonstration of that capability will be included in the staff presentation at the May
2005 Board meeting.

The CWCB and the USBR are collaborating on the "Enhanced Snowpack Assessment"
Project that uses modeled snowpack from the Snow Data Assimilation System
(SNODAS) and tailors and downscales model output to lKm resolution for Colorado's
eight major river basins. The project uses the USGS eight digit HUC basins creating
about 44 sub-basins worth of data this aggregated back to the eight major river basins.
The two major goals are to 1) develop quantitative snowpack numbers, and 2) link
modeled snowpack to hydrologic models for streamflow forecasts. Maps are online at:
http://wvvvv.usbr.gov/pmts/rivers/awards/SNODAS/SNODAS CO hist.html. A sample
SNODAS map is shown below for illustration purposes.

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