SWSIReportJuly2007 - Laserfiche WebLink

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GUNNISON BASIN Basinwide Conditions Assessment The SWSI value for the month was -0.5. Flow at the gaging station Uncompahgre River near Ridgway was 628 cfs, as compared to the long-term average of 555 cfs. Storage in Taylor Park, Crawford, and Fruitland reservoirs totaled 1060/0 of normal as of the end of June. Outlook June is typically the driest month of the year in western Colorado and June, 2007 was no exception. Montrose had only 0.28 inches of precipitation all month and that occurred on the 11th and 12th. Stagnant high pressure set in mid-month, forcing temperatures in the upper Gunnison basin into the 90's and even 100 in Grand Junction. The extreme heat dried all non-irrigated areas and put wildfire watches into effect. Natural streamflow diminished quickly throughout the basin during June. Where available, reservoir releases for irrigation needs have begun in earnest. The demand is highest on irrigated ground below the Grand Mesa but other parts of the Division such as the Paradox valley, the Gurley system, Fruitland Reservoir, and Fruitgrowers Reservoir began early releases. The sudden drop-off in streamflow will create "on- call" situations on many tributaries of the Gunnison River. Particularly tight will be the North Fork of the Gunnison and its tributary, the East River, At the last report, Blue Mesa Reservoir was not expected to fill and probably reached a maximum level on July 2 at 787,000 acre-feet or about 950/0 of capacity. The USBR increased releases from the Aspinall Unit on July 3 to meet demand from the Gunnison Tunnel. Flow into the Black Canyon rose to about 600 cfs that day. Taylor Park, Paonia, Crawford, and Ridgway Reservoirs are still near spill. Releases from those reservoirs for irrigation requirements should begin in July. The reservoirs on the Grand Mesa are already supplementing natural stream flow in the Kannah, Surface, and Ward Creek drainages. Administrative/Manaqement Concerns Water Court Case No. 01 CW05 is the filing by the USA to quantify the water rights of the Black Canyon. This 2001 Court filing has over 380 opposing parties, although many have already stipulated out. Negotiations between the parties heightened during the spring and a lot of progress has been made. However, Water Judge Steven Patrick set the matter for an eight-week trial, June and July of 2009, in an effort to move this landmark case towards completion. Public Use Impacts The initial abundant reservoir supply has made conditions look better than the poor to fair spring snowpack and runoff forecast. Streamflow will likely drop drastically in July and August, but will hopefully be boosted by summer rai ns. Jul-07 GJNNISQ\j BASIN SI\JS. HISTORY 4.0 3.0 I- 2.0 W S W 1.0 ::J ---l <( > >< 0.0 w o ~ -1.0 >- 0:: o -2.0 -3.0 -4.0 Jan-98 Jan-99 Jan-OO Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 rvlCNTH / YEAR UNCOMPAJ--IGRE RIVER NR Rlrx3WAY, FLOW BY WATER YEAR 250,000 Q) 200,000 Q) LL ill U <( S- 150,000 o .....J LL W ~ 100,000 <( .....J ::J ~ a 50,000 6