The Gila/San Francisco Water Commission met Tuesday, Jan. 15, in Silver City.

The first item of business was to pass the Open Meetings Resolution, with the only change being the year.

Next, commissioners chose their officers for 2013. Vance Lee, who has been chairman since the beginning of the organization said he chose not to continue as chairman because of personal reasons. He assured the members he will continue to be active in the group.

Lee nominated Tom Bates, who represents Deming and Luna County Soil and Water Conservation District. Bates is the new chairman.

Because Bates was the former vice chairman, a new one was elected.  Donnie Stailey, representing the Gila Basin Irrigation Commission, nominated Bill Webb, who represents the San Francisco Soil and Water Conservation District. Webb was elected.

The treasurer, Bill Woodward, who represents the Grant Soil and Water Conservation was retained, after he was nominated by Archie Payne of the village of Virden.

Bates gave a report on the Interstate Stream Commission public meeting on the Arizona Water Settlements Act proposals now before the ISC the evening before in Deming. He said he noticed no one from Luna County was present.

ISC Deputy Director Craig Roepke said two of the presenters at that meeting were in the GSFWC audience and asked if the members would like to hear the presentations, which they did.

"The third one from Interra could not be here, so I will try to summarize the third presentation, while the other two set up," Roepke said. "The Interra presentation was on different ways to conserve water. The ISC contracted with Interra to look specifically at whether the conversion to drip irrigation in the Deming area was working. They used LandSat technology, and picked equivalent pairs of crops, with 14 acres in drip irrigation and 10 acres in flood irrigation.

"The areas that were drip irrigated were significantly cooler," Roepke continued. "The drip irrigation works kind of like a swamp cooler, taking the calories out of the air. But cooler indicates more evaporation, just as with a swamp cooler. The drip-irrigated areas were growing more crop and evaporating more water, so they were using more water."

The two crops that were paired were cotton and milo, he said. "Interra could see more crop, with drip irrigation, so it is an advantage to the farmer, but the downside is that it is depleting the aquifer faster."

"Then, Interra looked at the color of the crops," Roepke said. "Again it confirmed that there was more green in the drip-irrigated acreage. It helps the farmers, but the conclusion is that it uses more water. That's intuitive. As you increase crop yield, you use more water. Interra will continue to look at the data to determine how much water loss there is to evaporation."

Bates asked about the rate of the drawdown of the aquifer.

Roepke said the decline has been about 1.3 to 1.4 feet every year for the past 15 years. "That includes the amount of irrigated acres dropping yearly."

He said the state engineer allows farmers to deplete their full allocation. Roepke also said if farmers did not do drip irrigation, the land would be fallow.

Gerald Schultz, representing statewide resource, conservation and development districts, asked if the process was similar to using test plots.

"Essentially we're using the acreages as test plots," Roepke said. "If you're trying to conserve water, drip irrigation is not the way to go, but if you're truing to increase your crop, drip is the way to go."

Stailey asked if the drought and more municipal use of water were taken into consideration.

"All users are captured in the drop of the aquifer," Roepke said. "Deming water usage has remained fairly constant, while there is a decreasing amount of irrigated acreage. The drop in the aquifer is consistent with more water being used on fewer acres."

Jeff Riley of the Phoenix office of the U.S. Bureau of Reclamation presented the status of the technical analyses of Tier 2 proposals being considered by the ISC. "We received a letter from the ISC on Oct. 15, requesting our involvement, specifically on engineering on diversion, conveyance and storage proposals. We are doing appraisal-level work of the conceptual designs using existing information. Some of the work on economic analyses is gathering baseline information for cost benefit and regulation impacts."

He and others started with a site visit in late November. "The storage locations are principally tributaries coming into the Gila River with water stored behind the river and released when needed. We are looking at four diversion points in the Cliff-Gila area and a number of storage tributaries concentrating in the Upper Gila, because released water can be used downstream. This does not preclude storage in Redrock or Virden."

The diversion points include the Fort West and Upper Gila ditches. "We are looking at a new conveyance engine in Winn Canyon, Bell Canyon and Spar Canyon." He said the area has flood control embankment dams that were built in the 1940s and '50s. He showed maps of the topography and possible conveyance.

The diversion structures would be small and would push water into the intake, with the water being conveyed out by gravity flow. "We need to determine how much water can be stored on the tributaries. The Lower Cliff-Gila Valley near the two towns has 14 potential storage drainages, including Schoolhouse Canyon and Mangas Creek. We have identified one diversion point at Redrock where the stream gauge is."

He said the critical information the Bureau of Reclamation does not have and won't have at the end of the appraisal is the geology of the area. Riley pointed out the conveyance alignment would be a mixture of pipelines, with open channel flow as much as possible, and in addition, tunnels and siphons.

"We will have the final report by July 31, 2014," Riley said. "Comment on the draft will be in the spring of 2014."

Lee asked if the information would be available, and Roepke said it would be posted to the nmawsa.org website.

Riley said Reclamation was not intending to recommend any course of action, but would provide as much technical information as possible. "We will also look at infiltration galleries and underground storage."

Schultz asked if the comment period would be appraisal level or feasibility study level. Riley said the schedule is for appraisal, but may go later into feasibility.

M.H. "Dutch" Salmon of the Gila Conservation Coalition said he was wondering how water would travel from the upper diversion points, because mountains are in the way.

"We plan to work with gravity flow," Riley said. "The conveyance would follow the topography, mainly in the river valley, but it could be challenging in spots."

Salmon asked if up to 350 cubic feet a second would be taken at a diversion.

"Yes, the maximum diversion of 350 cfs could be taken," Riley said.

Salmon how big a pipe or ditch would be required to convey that much water.

"It is dependent on the slope we select," Riley said. "A pipeline could have 6 to 8 feet in diameter pipes and a ditch could be 15 feet across depending on depth and slope. I hesitate to give firm numbers. We haven't gotten into hydraulics yet."

The report by ISC engineer Helen Sobien on the AWSA proposal in the Mimbres Valley and the rest of the meeting will be covered in a subsequent article.