Courtesy of Nicole Langley The Sanchez Reservoir in Costilla County is captured in this 2021 photo. Photo courtesy of De Golyer Library, Southern Methodist University In this 1909 photo, Costilla Estates Development Company surveyors planned an elaborate irrigation system in Costilla County to lure settlers from Europe and the eastern U.S. The irrigation system failed, and the settlers never materialized.

COSTILLA COUNTY— The Sanchez Reservoir was built in 1912 and designed to impound approximately 103,000-acre feet of water by the construction of a large earthen dam. It has always leaked. In 2015, the Colorado Division of Water Resources restricted storage to 20% of capacity due to safety issues caused by seepage through the dam.

The Sanchez Ditch and Reservoir Company recently secured over $646,000 to study the deficiencies at the dam as a step towards repairing it to the intended capacity.

The Sanchez is the largest reservoir in Costilla County, the Mountain Home and Smith were all constructed by the Costilla Estates Development Company.

The modern history of the Costilla Estates dates back to the Territorial Governor of Colorado, Willian Gilpin, who was a promoter of Costilla real estate and banked on cheap land and the promise of endless water. In 1862, he and a consortium of foreign investors bought the Sangre de Cristo Land Grant for about 4 cents per acre. $41,000. Gilpin fared well, the following year he sold part of his interest in the land for $162,000.

Gilpin and his associates formed the Colorado Freehold Land Association in 1868. That would soon become the United States Land Freehold Land and Emigration Company which encouraged land purchases and immigration from Europe. After that enterprise collapsed and a series of transactions, in 1908 the Costilla Estates Development Company bought the 500,000-acre tract and built several reservoirs including the Sanchez. Promises of the agricultural values of the region came early. Noted explorer and government geologist Ferdinand Hayden said of the area, "The land embraced in the Sangre de Cristo Grant forms the eastern and southern portions of the [San Luis Valley] and is by far the finest agricultural district I have seen west of the Missouri River." Hayden went on to speculate the land "might be divided into airable and pastoral land." As a historical footnote, Hayden would later lead the Hayden Geological Survey of 1871 that would map what would later become Yellowstone National Park

The reservoirs were built using steam shovels, pickaxes, other hand tools, and horse-drawn teams of wagons. A 1909 article in the La Jara Chronicle detailed plans of the development company to bring 10,000 settlers to the area and boast of fertile soil. "The plan being so attractive that an excellent class of settlers will be secured, and the opening of the land will result in a veritable boom." Promotional literature from Costilla Estates exclaimed "Completed Reservoirs." The marketing included claims the land was "irrigatable," and the land slope "prevented the possibility of seepage ever occurring."

The Sanchez Reservoir and dam took two years to build and was completed in 1912. The dam has always had seepage. The 10,000 settlers never came, according to US Census data, the county population peaked at 7,533 in 1940 and is now about 3,500.

Nicole Langley Restoration Project Coordinator with the Sanchez Ditch and Reservoir Company, a non-profit company said the reservoir has operated for, "The last 114 years with a constant deficiency, as primitive methods were used to build the reservoir. Now we are dealing with the consequences of that. The main issue is dam safety, that is the primary focus, to restore the safety of the dam. We have had continual seepage from the very beginning. We have found the source of the seepage and now we are doing the engineering [studies] for the repair of the dam." Recently, state funding for $485,208 was allocated for engineering studies with an additional $64,694 from the Rio Grande Basin Roundtable, and $97,042 in matching funds from the reservoir company. The funds will be used to study deficiencies at the dam and not the actual repairs.

The reservoir company is owned by 22 stockholders and provides water to hundreds of people in the Culebra River watershed according to Langley.

The engineering company AECOM has been retained and will be working with Willowstick LLC for the mapping and modeling of groundwater seepage and flow paths. Langley said the funding will become available in August and the studies will take an additional two and a half years to complete.

Former Congressman John Salazar who is on the board of the reservoir company said that in 2015 due to sinkholes in the dam that impound the water for the reservoir the state dam safety engineer put restrictions on the dam limiting the amount of water in the reservoir to about 22,000 acre-feet, "so even on good years, we just can't store the water that we need for crops. The most critical issue here is dam safety, when I was in Congress, we passed a dam safety bill and that is what we are after. If we get that reservoir repaired it would have a great economic benefit for Costilla County and the state. I used to draw a lot of people to recreation." Salazar added, "We're going after Senate and House members to see if, under the dam safety bill, Colorado can get some funding to help restoration. we've put in about $47,000 for the scientific study as to where the leaks are happening."

In a 2023 letter Colorado Division of Water Resources Division Engineer Craig Cotten advocated for funding to repair the dam and stated the storage limits the Colorado Division of Water Resources imposed, "were due to significant dam safety issues caused by seepage through the dam and the potential for a catastrophic dam failure at higher storage levels."

In addition to providing water for irrigation, Langley said the reservoir company is planning for recreation and is collaborating with Colorado Parks and Wildlife [ it is within the Sanchez Reservoir State Wildlife Area], Trout Unlimited, Ducks Unlimited, and the Rio Grande Headwaters Land Trust.

The motto of the San Luis Ditch and Reservoir Company is, "Water is Life." Perhaps the recently secured funding will enable the reservoir to fulfill that statement and one day be filled to capacity.