MINERAL COUNTY — The San Luis Valley Irrigation District (SLVID) is anticipating moving its Rio Grande Reservoir expansion project into the final design stage by “late fall or early 2010,” according to SLVID Supervisor Travis Smith.

The final design stage is in the fourth of five phases of the project, which would expand the large reservoir approximately 20 miles southwest of Creede by 10,000 acre-feet. The fifth stage would include the expansion of the reservoir, which is near the headwaters of the Rio Grande.

For those not up on water lingo, an acre-foot is the volume of one acre of water surface area to the depth of one foot. To put that in perspective, an acre-foot is equivalent to about 326,000 gallons and the average American family uses between .25 and one acre-foot of water per year.

Currently in the third phase, the district is looking at its Reservoir Allocation Enhancement Model, which deals with how to operate the reservoir once the expansion project is completed, specific to the needs of the district and its water users, along with compact and direct flow storage. Smith, also the chairman of the Colorado Water Conservation Board (CWCB) and its representative on the Rio Grande Roundtable, said that this third phase will cost $100,000, and is being funded through the CWCB’s water supply reserve account.

The district is currently consulting with the Colorado Division of Water Resources, the District 20 Water Commissioners, the Rio Grande Water Users Association, the Nature Conservancy and Trout Unlimited on the expansion project.

“It’s a 100-year-old reservoir, and it needs a fix,” Smith said when asked why the SLVID undertook the project in the spring of 2002. “It has physical repair issues that need to be addressed so you have a reservoir to meet the needs of the next 100 years.”

Smith said that, in the first two phases of the project, the district looked at possibly expanding the reservoir by 100,000 acre-feet and later by 50,000. “Because of wetland and physical design issues of where the reservoir is located, we determined that 10,000 acre-feet was a cost-effective enlargement.”