BOISE — The Idaho Department of Water Resources has issued an order requiring Eastern Snake Plain Aquifer well users to install closed-conduit measurement devices by 2018 to better monitor their water use.
Idaho Ground Water Appropriators, Inc., has obtained a $1.6 million Bureau of Reclamation Smart Water grant to help growers cover up to 45 percent of their costs. IGWA Executive Director Lynn Tominaga estimates the equipment and installation cost at roughly $5,400 per well.
“Everybody we have talked with has said flow meters are good because you have better control over how you manage your water for your crops,” Tominaga said.
The requirement for groundwater users to install flow meters by 2018 was included in last summer’s water call settlement agreement between IGWA and the Surface Water Coalition. IDWR Deputy Director Mat Weaver said the department opted to make it a general requirement to avoid deterring growers from participating in the settlement.
Small wells irrigating less than 5 acres, or drawing less than 0.24 cubic feet per second, and domestic or stock water wells are exempt from the order.
Weaver explained the order, issued on June 15, replaces previous measurement orders imposed by individual ESPA water districts from 2001 through 2013. Weaver said the prior orders had inconsistent language, allowing many users to “fall through the cracks,” and were overly lenient in granting exemptions allowing growers to use a less accurate estimation based on power use.
The department had granted exemptions on 3,500 of 5,500 wells. Under the new order, Weaver said, power calculations will be allowed only under the simplest scenario — involving a single well and irrigation discharge point with no pivot end gun where the aquifer level doesn’t fluctuate.
Weaver said closed-conduit measurement devices must be accurate within 2 percent. Utah State University has tested devices for IDWR’s approved list of manufacturers. By contrast, IDWR audits have found most power-based calculations are off by at least 10 percent.
The water call settlement also requires groundwater users to reduce their combined average annual consumption by 240,000 acre-feet, and Blackfoot grower Brian Searle said accurate measuring will be critical toward its success. Searle, who already has four measurement devices in place and will have to install five more, noted the order comes at a time when growers are coping with low commodity prices. American Falls grower Klaren Koompin has devices in place on three wells and will have to install 22 more, which he estimates will cost $80,000.
Surface Water Coalition attorney John Simpson said his client has filed a petition for IDWR to reconsider the order, believing it should be expanded by 250,000 groundwater-irrigated acres to encompass the entire territory of the most current ESPA groundwater model. IDWR’s order covers only an area known as the Rule 50 boundary, which offered the best understanding of the “area of common groundwater” in 1994, but remains in effect for legal purposes.
“That (updated) model boundary has been identified as the best science available by the court system, and we should be using it to require measuring devices and reporting of data,” Simpson said.