Editor's Note: This is the final in a series of three articles on the Interstate Stream Commission quarterly meeting addressing the Arizona Water Settlements Act planning process.
By Mary Alice Murphy
David Anderson, ISC environmental scientist, gave a presentation on the AWSA Ditch Improvement Proposals, which included preliminary engineering and environmental assessments.
"It covers four proposals—the 1892 Luna Irrigation Association Ditch, the Pleasanton East-Side Ditch Co., and the Sunset and New Model ditches in Hidalgo County," Anderson said. "The four proposals are to use AWSA funding to conserve water by improving the community ditches."
The ISC hired Portage Inc. to deliver the preliminary engineering assessments for feasible alternatives and to assess environmental impacts.
The material suggested to be used for the improvements is high-density polyethylene pipe, because it has tight joints, alleviating leakage.
The environmental impact assessments consider impacts to land use, soils, water resources, ecological resources, historical and cultural resources, air quality, aesthetics, noise and socioeconomics under the proposed action and no action alternatives.
The Pleasanton East-Side is a 20,000-foot community ditch, with 18,000 feet of 50-year-old concrete lining. It is the last water user on the San Francisco River before it goes to Arizona. It has 24 water-rights holders, who produce a variety of crops. Most of the ditch would be closed with pipe, except for a few residents who want a portion kept open for aesthetic reasons. The project would reline the ditch or replace it with closed pipe with a cost estimate of $1.831 million to $2.662 million.
"In the environmental impact assessment, the only potential significant impacts would be for the no-action alternative and would be on water resources, for seepage and loss, and on socioeconomics, because folks on the tail end of the ditch have trouble getting water into their fields," Anderson explained. "All the ditches have the same significant impacts."
He said the 1892 Luna Irrigation Association is the first user on the San Francisco in New Mexico. It has a temporary earthen structure, which gets washed out in floods, and conveyance losses.
"They want a permanent diversion structure and conveyance systems," Anderson said. "The ditch irrigates 225 acres and the improvement would line the ditch or install pipe for a cost estimate of $1.364 million, which does not include NEPA."
The Sunset Canal and New Mexico New Model Canal made a proposal together. The Sunset Canal serves 2,236 acres in New Mexico; the New Model serves 315 acres in New Mexico.
Long-term maintenance issues and conveyance losses would be resolved by pipe and additional infrastructure. The Sunset cost estimate is $9.11 million to $11.306 million. The New Model cost estimate is $3.793 million to $4.777 million.
"Two representative proposals out of 10 ditches in a Catron County watershed proposal were evaluated," Anderson said. "They are the Glenwood North Lower and the Mid Frisco/Kiehne."
The improvements would be ditch linings or closed pipe, permanent diversion structures, sediment clean-outs and holding ponds.
The Glenwood North Lower is estimated to cost $447,000-$575,000; the Mid Frisco/Kiehne to cost $1.332 million to $1.65 million.
The Glenwood North Lower serves a fishery and may have asbestos pipe, so there may be disposal issues.
"This is ongoing work and the report is available on nmawsa.org," Anderson said.
Vic Topmiller, Silver City resident commented and asked: "That's a large amount of money to enclose water in pipes. Why not transfer to wells and use groundwater?"
"Most acequias have boards, and the projects were not proposed that way," Anderson said. "They want to repair their ditches."
"Doesn't water loss from the broken linings go back into the aquifer?" Topmiller asked to which Anderson replied: "In a narrow alluvial valley, the gradient is back toward the river through the shallow aquifer."
"My third question is: Doesn't sealing the ditch eliminate wildlife habitat?" Topmiller inquired.
"It would be a temporary disruption, but I don't see a long-term impact," Anderson replied.
A man from the audience asked: "On the Kiehne Ditch, is ponding a mitigation? It is suggested it would support wildlife. Water users pay for water from the releases. If these are done, 30-50 percent of the water will be left in the river, because of more efficient use."
"If the water is consumed by evaporation, it is still considered consumptive use and irrigators are charged," Anderson clarified.
"I haven't heard anything about metering," Kyle Johnson said.
"At present, the water user is required to meter from the gate and gauge to calculate the consumptive use," Anderson said. "It is mandated by the 1964 Arizona v. California Supreme Court case."
"Is metering at the individual ditch?" Johnson asked.
"All ditches are gauged," Anderson said. "The Office of the State Engineer does field work to calculate the use by reach."
"The improvements are on the existing ditches?" Johnson asked. "I assume the water rights are already allocated. Do these have anything to do with the additional 14,000 acre-feet of water?"
"Yes, these are improvements on existing ditches," Anderson said. "Yes, all water rights were adjudicated by the Supreme Court. None of these proposals considered the additional AWSA water. There is no proposal to use the additional water in the San Francisco Basin."
Mary Burton Riseley commented and asked: "These seem very affordable under the $66 million. A proposed diversion could be $500 million. Could these improvement be siphoned off from the funding for the diversion and storage projects?"
"They are not mutually exclusive," Anderson replied.
"I heard from a (ISC) commissioner that if diversion and storage were the determined project, there would be no smaller ones," Riseley said.
"I saw the estimates," a man said. "What is the financial benefit for getting more water?"
"Portage was asked to do a preliminary engineering assessment," Anderson said. "They talked to residents and estimated a 25 percent increase in benefit from the water."
"I do the estimates," Steve Piper, Reclamation economist, said. "A benefit is in our summary sheets. We have a range of benefit estimates from $25 per acre-foot to $140 per acre-foot. The report will be ready in July, as well the regional economic analyses, if you didn't do a project."
Although facilitator Reese Fullerton tried to get people to stay to ask questions about agricultural conservation, diversion and storage, municipal effluent, municipal conservation and watershed restoration, people were getting up and leaving, as well as talking among themselves, so he adjourned the meeting.