Snowpack/runoff news: The Rio Grande Roundtable gets the bad news about water year 2011 runoff

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From the Valley Courier (Ruth Heide):

Referring to the Rio Grande and Conejos River systems, [Division of Water Resources Division 3 Division Engineer Craig Cotten] said, “We are looking at about a 75 percent of average year on both systems, roughly.”

Cotten said he is maintaining the same streamflow forecast in May as he had in April for both the Rio Grande and Conejos. He said although the Natural Resources Conservation Service (NRCS) has bumped up its estimated streamflow forecast, he is maintaining a more cautious prediction. His office is looking at a preliminary annual flow on the Rio Grande at Del Norte of 480,000 acre feet, the same as predicted last month…

Of the 480,000 acre feet forecast, the Rio Grande would owe 121,000 acre feet to downstream states as obligated by the interstate Rio Grande Compact. Colorado is able to deliver much of that during the wintertime, Cotten said, so only about 10 percent of that obligation would have to be sent downstream during the irrigation season. However, because the system is seeing some return flows right now to help with the compact obligation, the current curtailment of ditches on the Rio Grande is only 6 percent, he added.

Cotten said his office is keeping the same forecast numbers for the Conejos River system as last month, although the NRCS forecast went up slightly there as well. He is looking at 240,000 acre feet annual flow on the Conejos, with 69,000 acre feet of that required to be sent downstream, or a delivery obligation of 16 percent during the irrigation season. The Conejos system is not seeing the same return flows to the rivers as the Rio Grande, so the curtailment right now is 16 percent…

Cotten also reported on the status of the Elephant Butte and Caballo Reservoirs in New Mexico that hold the water for the Rio Grande Compact. Credit water from Colorado and New Mexico is stored in those reservoirs, for example. The reservoirs hold more than two million acre feet but right now contain a fraction of that. “They are dropping significantly every day,” Cotten said. He said there’s a good possibility that all the storage water in Elephant Butte/Caballo will be used up this year so that all that will be left will be credit water and San Juan/Chama water to keep the system going. Most of the credit water is New Mexico’s, he added.

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