Farmers could face irrigation shortages

August 09, 2001
By Marvin Tessneer
Las Cruces Sun-News

The Elephant Butte Irrigation District Board of Directors is anticipating a dry cycle that would affect farmers' water supply, according to U.S. Bureau of Reclamation reports.

A graph supplied by the bureau shows that a dip in the water supply started last year.

District Manager Gary Esslinger, speaking at a district meeting Wednesday, said the trend fits what farmers fear and what they label the "25- to 30-year dry-wet cycle."

The reports were issued by the bureau's El Paso Field Division Manager Filiberto "Bert" Cortez.

The graph, which indicates the water supply by surface level elevation in Elephant Butte Reservoir, shows an adequate supply from the early 1920s to the early 1950s.

But the water supply dropped during the 1950s. That was a period when farmers had to drill supplemental wells because the reservoir supply, filled by the Rio Grande, was low and inadequate. In some years the reservoir supply was so scant that farmers had less than one acre-foot of surface water to irrigate their fields, farmers recall.

Starting in the late 1970s, storms built up the snow packs in the northern New Mexico and southern Colorado Rockies, and the irrigation district was able to start out the seasons with a full two-acre-foot allotment. During some years, the district was able to sell the farmers up to four acre-feet if they needed it.

But Cortez' report indicates that the cycle is coming around to dry years again. The snow runoff into Elephant Butte Reservoir last spring was far less than normal, he wrote.

The normal flow through the San Marcial measuring station north of Elephant Butte is 500,000 acre-feet. But this summer, the reservoir received only 241,000, bureau hydrologist engineer Wayne Treers said.

The early spring forecast called for 560,000 acre-feet, or 112 percent of normal. But the Albuquerque bureau office held 143,000 acre feet upstream in the Vado Reservoir for the Middle Rio Grande Conservancy District, and the Rio Grande Compact Commission authorized the holding of 60,000 acre-feet to preserve habitat for the endangered silvery minnow.

Other losses have not been accounted for. Treers said he has asked the U.S. Natural Resources Conservation Service to determine what caused the extra losses.

In reservoir specifics, Cortez reported that at the end of June the water storage in Elephant Butte was 1,047,600 acre-feet. At the present rate of use, the figure is expected to drop to 862,600 by the end of October.

As a measure of the problem, the Elephant Butte capacity is 2,023,000 acre feet.

Caballo Reservoir storage at the end of June was 72,740 acre-feet. But the bureau is planning to decrease the storage to 6,080 acre feet at the end of September so workers can inspect a structure that releases water through a tunnel.

The bureau plans to increase the Caballo storage to 41,780 acre-feet by December, Cortez reported.

The board of directors also voted to set the last EBID irrigation order date at Oct. 5 and to close the Caballo gates on Oct. 12.

Board members are concerned that the bureau might want to "dump" water to lower the Caballo level for the intact structure inspection. Esslinger said he has seen it before -- late rains could fall in the Animas and Percha creeks' water sheds above Caballo and flow into the reservoir. That is water that could stored, he said, and the board would not like to see it wasted.

"We try to coordinate water delivery to our farmers with the bureau's plans," Chairman Gary Arnold said. "But we want to minimize waste in our system."

The bureau's latest reservoir storage figures also indicate a water shortage trend:

Aug. 1 this year -- Elephant Butte, 946,000 acre-feet, Caballo 41,000 for a total of 987,000.

July 31, 2000 -- Elephant Butte 1,356,000 acre-feet, Caballo 44,070 for a total of 1,400,470.

A high rate of irrigation orders during the hot months of June and July also drew down the water supply, Watermaster Ricardo Bejarano reported.

Ditch riders diverted 71,804 acre-feet during July and 74,236 during June to irrigate crop fields in the Mesilla and Hatch valleys, Bejarano reported, leaving a balance for this season of 171,826 out of the initial 494,979 bureau allotment.