• Sunday, January 31, 2016 Enterprise Editor Virginia Hutchins [ 208-735-3242 • vhutchins@magicvalley.com ] • B1
THE BIG STORY
PHOTOS BY STEPHEN REISS, TIMES-NEWS
Twin Falls Canal Co. field supervisor Louis Zamora on Jan. 5 walks across the main gates at Murtaugh Lake, one of the region’s top sites for intentional aquifer recharge. A pump at the headgates keeps the lake water circulating so it doesn’t freeze and can continue seeping into the ground.
Spreading the Risk Groundwater Pumpers Prepare to Pay the Price for Historic Deal that Averted Water Crisis
Aquifer Recharge in Line for Big Boost in 2016
MYCHEL MATTHEWS mmatthews@magicvalley.com
The stark reality finally sunk in. The Eastern Snake Plain Aquifer has reached its lowest point since surface-water irrigators began inadvertently filling the aquifer in the early 20th century. But surface- and groundwater users, after a long and bitter battle over water rights, last year agreed on a way to stop the declining aquifer levels and vowed to reverse the trend. The aquifer’s decline has gone far beyond being a waterrights issue. The aquifer’s very existence, the state’s agriculture and its economic health are at risk. Without the 2015 deal, Idaho would have to enforce a 10-year-old water delivery call — a demand by a coalition of surface water users against groundwater users with newer, junior rights. To make the deal work, the 2016 Legislature will have to fund millions of dollars in aquifer sustainability projects. “Here’s what’s at stake,” said House Speaker Scott Bedke, R-Oakley, who bartered the deal. “If there were no agreement, then these water calls would come into effect. Junior water rights would have to be curtailed and hundreds of thousands of acres would go idle.” Either way, it’s going to hurt. But the water deal lessens the huge risks to southern Idaho farmers, their bankers and all the economic sectors that depend on them.
More Inside
NATHAN BROWN nbrown@magicvalley.com
these objectives: • Mitigate for material injury to senior surface water rights. • Provide “safe harbor” from curtailment to the groundwater users who agree to the terms of the agreement. • Minimize economic impact on individual water users and the state economy arising from water supply shortages. • Increase reliability and enforcement of water use, measurement and reporting across the Eastern Snake Plain. • Increase compliance with all elements and conditions of all water rights and increase enforcement when there is not compliance. • Deve l o p a n a d a p t ive groundwater management plan to stabilize and enhance Eastern Snake Plain Aquifer levels. Someone’s about to pay a huge price. But it’s an arrangement that saves anyone from losing it all.
BOISE • When the Magic Valley’s lawmakers went to Boise this year, they knew that funding recharge of the Eastern Snake Plain Aquifer was going to be one of their top priorities. House Speaker Scott Bedke, R-Oakley, who helped to broker last year’s historic agreement between surface- and groundwater users, said that although the state might not be part of Bedke the deal, it needs to send a strong message of support to the parties, such as the farmers who sacrificed some of their allotment to make the deal work. “We need to fund a robust managed recharge program,” he said. Rep. Maxine Bell, R-Jerome, cochairwoman of the budget-setting Joint Finance-Appropriations Committee, said aquifer recharge funding was one of her top priorities for the session, along with education and wild- Bell fire funding and getting money for a crisis center in the Magic Valley. Bedke said recharge would require both some additional one-time funding in the 2016-17 budget year and long-term funding — preferably something other than cigarette tax revenue, which is falling every year as people quit smoking and is also part
Please see WATER, B2
Please see AQUIFER, B3
Jerome Public Works water operators Daniel Bowman, left, and Jason Cunningham repair an irrigation line for canal water Jan. 15 in Jerome. The city uses both groundwater and surface water in its municipal system.
Averting Curtailment Over the years, the Idaho Department of Water Resources has over-allocated groundwater, said Brian Olmstead, general manager of Twin Falls Canal Co., which owns some of the region’s oldest water rights. After six consecutive years of drought in the late 1980s and early ’90s, Water Resources placed a moratorium on issuing new permits for consumptive water use in the Snake River Basin upstream from Weiser. ThenDirector Keith Higginson issued the moratorium in April 1993. Since then, the department has dealt with water call after water call, continuing “to kick the can down the road” without working on a solution to the problem, Olmstead told the Times-News. “Groundwater users are mining the aquifer,” he told shareholders at January’s annual meeting. “More water is being drawn from the aquifer than is going in.”
Olmstead’s words came as no surprise to anyone in the room. The canal company and other members of the Surface Water Coalition made a water delivery call against Eastern Snake Plain Aquifer groundwater users back in 2005. Last year, the ongoing water call made headlines when Bedke sat both sides down to talk about finding a way to avert curtailment, once and for all. Even Idaho Gov. C.L. “Butch” Otter got involved, suggesting the two sides meet without lawyers. Water Resources accepted agreements between major players in the water call last fall, and now state legislators are addressing aquifer recharge to replenish the resource.
The Settlement Agreement T h e m a jo r a g re e m e n t , between the Surface Water Coalition and the Idaho Ground Water Appropriators, outlined
Aquifer Model Needs More Study, B2 • What is a Water Right? B3 • Cheese Plant Reclaims Water from Milk, Eyes Aquifer Recharge, B4
B2 • Sunday, January 31, 2016
Aquifer Model Needs More Study MYCHEL MATTHEWS mmatthews@magicvalley.com
JEROME • The Eastern Snake Plain Aquifer is a 10,800-squaremile volcanic sponge swooping from northeastern Idaho near Ashton to as far south as Burley and as far west as King Hill. The main ingredient — that which separates the aquifer from the surrounding geology — is quaternary basalt, a relatively
young (1.6 million-year-old) bedrock that is quite porous compared with older basalts. The aquifer lies mostly north of the Snake River. Twin Falls County is predominately covered with tertiary basalt, an older and far less permeable bedrock and lies, therefore, outside the Eastern Snake Plain Aquifer. The main natural outlet for water in the aquifer is near Hagerman at Thousand Springs
— where water pours from the Snake River Canyon wall — although the aquifer leaks into the Snake from springs all along the river. The water level in the aquifer rises with precipitation, “incidental” recharge from leaking canals and flood irrigation, and intentional recharge by water districts and canal companies. The level falls with groundwater pumping.
In addition, increased efficiency in irrigation technology — leading to reduced incidental recharge — has contributed to the decline in the aquifer, said Sean Vincent, manager of the Idaho Department of Water Resources hydrology section, the group responsible for the operation and maintenance of the Eastern Snake Plain Aquifer model. The current model of the aquifer resulted from a large study of
regional aquifer systems in the 1990s. Hydrologists haven’t fully mapped the movement of underground water in Idaho; state legislators this year are expected to appropriate money for further aquifer modeling. Though not a part of the Eastern Snake Plain Aquifer, Twin Falls Canal Co. derives some of its water rights from the aquifer’s spring water that feeds the Snake River above Milner Dam.
PHOTOS BY STEPHEN REISS, TIMES-NEWS
As Twin Falls Canal Co. participates in aquifer recharge, this winter is only the second in the past 50 winters that Murtaugh Lake has been full of water.
Major Water Players
The Surface Water Coalition includes American Falls Reservoir District, Burley Irrigation District, Milner Irrigation District, Minidoka Irrigation District, North Side Canal Co. and Twin Falls Canal Co. The coalition also includes A&B Irrigation District, although the district holds more groundwater rights than surface water rights. Idaho Grounds Water Appropriators Inc. includes Aberdeen-American Falls Ground Water District, Bingham Ground Water District, Bonneville-Jefferson Ground Water District, Carey Valley Ground Water District, Jefferson Clark Ground Water District, Madison Ground Water District, Magic Valley Ground Water District, North Snake Ground Water District and FremontMadison Irrigation District. Southwest Irrigation District belongs to IGWA but is working on its own mitigation plan. Some cities — including Blackfoot, Jerome, Rupert, Heyburn, Paul, Chubbuck and Hazelton — are members of IGWA but have joined the Coalition of Cities and are working on a separate mitigation plan, as is the city of American Falls. The Coalition of Cities includes Heyburn, Rupert, Burley, Declo, Paul, Carey, Hazelton, Shoshone, Jerome, Richfield, Dietrich, Bliss, Gooding and Wendell. A&B Irrigation District, in Minidoka and Jerome counties, holds both surface water rights, and senior groundwater rights with a priority date of 1948. The irrigation district is not a member of IGWA and has signed its own mitigation plan.
Jerome Public Works water operator Daniel Bowman repairs a leaking fire hydrant Jan. 15 in Jerome. The city, a member of the Coalition of Cities, is among the groundwater users reducing their consumption. When the hydrant froze, it revealed a longstanding leak.
Water Continued from B1
Who Isn’t Playing or Paying
Groundwater irrigation districts must pull far more than their own weight in the Surface Water Coalition settlement agreement to make up for groundwater users who are exempt from the water call. Who’s exempt? Each domestic water user with an individual well may pull 13,000 gallons of water per day from the aquifer to water lawns, gardens and small pastures up to one-half acre. The drain on the aquifer from a growing number of rural residential developments is yet to be addressed. But until that time comes, the Idaho Ground Water Appropriators have agreed to take on the disproportionate burden of aquifer replenishment. Some counties are now requiring developers to keep any surface water rights on those parcels for irrigation.
Id a h o G ro u n d Wa te r Appropriators members, who represent the largest portion of the affected groundwater users, agreed to reduce groundwater consumption by 240,000 acre-feet annually. This amounts to about a 13 percent reduction and represents the amount of water needed to stop the aquifer’s decline. The current goal is to stabilize groundwater levels — represented by the water levels in 19 chosen wells — by maintaining 2015 levels through 2020. Groundwater users also agreed to limit their irrigation season, starting no earlier than April 1 and ending no later than Oct. 31 each year. That season shortening
isn’t enough to reduce use by 13 percent. Farmers using groundwater will have to idle some acreage, choose crops that use less water and increase irrigation efficiency. Under the state’s oversight, groundwater users will begin monitoring wells to make sure everyone does their part to meet the reduction. The long-term goal is to increase the aquifer to 19902001 levels by 2026, reaching a halfway point by 2023, using a state-sponsored, managed recharge program of 250,000 acre-feet per year.
Making It Law
While the settlement agreement between surface water users and groundwater users is legal and binding and does not need to become law, the 2016 Legislature will need to pass laws that establish the means for the agreement
to work, such as money for recharge infrastructure and aquifer modeling. Recharge simply means letting water soak into the ground and head for the aquifer — or injecting it through a well. Obviously, there is not enough water in the system to recharge during the irrigation season. Recharge must happen during the winter — and that means diversion sites must be modified to handle ice. Pumps and bubblers must be installed to keep water from freezing. Recharge water must be diverted around hydroelectricity plants and other structures. Until now, only limited recharge has happened. The state had an annual goal of recharging 100,000 acre-feet; however, Water Resources has averaged 75,000 acre-feet per
year since 2009. Wesley Hipke, the department’s recharge project manager, said the state used to pay a flat rate of $3 per acre-foot to defray recharge costs to irrigation companies in the lower valley of the Eastern Snake Plain Aquifer. The program used a stateheld recharge right, which remains a priority throughout winter to maintain a base flow of 500 cubic feet per second below Milner Dam. “The payment is for wheeling the water since the water being recharged is part of the IWRB’s (Idaho Water Resource Board’s) natural flow water right,” Hipke said. In 2014, Water Resources and three irrigation water providers conducted the state’s first extensive winter aquifer recharge effort. Please see WATER, B3
Sunday, January 31, 2016 • B3
What Is a Water Right? MYCHEL MATTHEWS mmatthews@magicvalley.com
WIN FALLS • All water in Idaho T is owned by the public; holding a water right does not give the water user ownership of the water. A water right simply gives the user the right to divert water. All water rights in Idaho exist for beneficial uses. Whether the water is diverted from a river or creek, or pumped from an aquifer, the user must declare a beneficial use for it. Irrigation, commercial, municipal, industrial, livestock, hydropower, recreation, aquaculture, native fish and wildlife — and, of course, domestic use — are all considered beneficial uses. Domestic water rights include water for personal household use, including drinking, bathing, laundry, sprinkling a lawn or garden (up to one-half acre), washing a car, and small-scale livestock. Domestic water rights include up to 13,000 gallons per day. A water right might be lost if not used, thus the “use it or lose it” concept comes into play. There are, however, statutory conservation defenses against forfeiture, including making deposits — credits for unused water — in the state’s water bank.
Two Types
PHOTOS BY STEPHEN REISS, TIMES-NEWS
Water flowing through the main gates at Murtaugh Lake forms ice below the gates Jan. 5. Above the gates, a pump keeps the lake water circulating below a layer of ice so the water can seep into the aquifer.
Water
Water uses are broken into two types: consumptive and non-consumptive. Consumptive use is when water is consumed or lost during its use. The largest consumptive use of water is irrigation, through evapotranspiration. Water is spread over the ground; some evaporates, and some transpires during plant growth. Other consumptive uses include dairies and manufacturing. Non-consumptive use is when
water is diverted but not consumed during its use; the Idaho Department of Water Resources classifies hydropower production as the only non-consumptive use.
Senior vs. Junior
Each water right is assigned a number and a priority date that determines who gets water during a shortage. This constitutes the “first in time, first in right” rule. Senior (oldest) water rights are fully satisfied before junior (newer) water rights, until there is no water left. When there is not enough water to satisfy all the water rights, junior water-rights holders get little or no water.
Enlarged Water Rights Prior to 1963, diversions were allowed without filing for rights. After 1963, water rights became the law. During Idaho’s 1990s water adjudication, the state gave “enlarged” water rights to users who had not followed the 1963 rules, but gave them junior water rights with a 1994 priority date.
Can I Get a New Water Right? Because of perennial water shortages, a moratorium in 1963 was placed on new consumptive-use water diversions on the Eastern Snake Plain Aquifer. If you want to farm land that has no water rights attached, or want to build a new dairy, you have to purchase an existing water right and transfer the rights to your property, unless you have a mitigation plan. On the other hand, new domestic water rights require no filing or recording, but you will need a permit to drill a well.
Continued from B2
Twin Falls Canal Co., American Falls Reservoir District No. 2 and Southwest Irrigation District were paid to recharge through a new, tiered payment program. The tiered structure ranges from $3 per acre-foot for up to 25 days of recharge to $14 per acre-foot for more than 120 days of recharge. A recharge project of the magnitude needed now requires the state’s support, and Idaho’s governor, House speaker and key legislators are giving the issue high priority this session.
What Happens to Existing Water Rights? Farming has always been risky. Each year, growers on Idaho’s Eastern Snake Plain try to outguess the market, outguess the competition and outguess the weather. Some hedge their bets by purchasing farm ground with the oldest water rights. “We paid a premium for our land,” said Ken Kostka, who holds senior surface water rights, and senior groundwater rights that date back to 1948. Idaho law dictates senior water-right holders get every drop of their allotment before those with junior rights get any. This will not change with the settlement agreement. Most Surface Water Coalition members hold senior water rights from the early 1900s. Most groundwater users, represented by Idaho Ground Water Appropriators, hold junior water rights procured decades later. A&B Irrigation District is a member of the Surface Water Coalition, but its members hold both surface water rights and
Aquifer Continued from B1
of the funding the governor wants to use to extend primary care coverage to the uninsured. “It’s going away anyway; it’s time to move it (recharge) to a general fund account that is stable year in, year out,” Bedke said. It looks like that funding is on track, if the increases Gov. C.L. “Butch” Otter recommended last week pass. Otter’s original budget proposal included $2 million a year in ongoing funding for sustainability projects, $10 million in one-time
Typical Water Usage
Holders of water rights must declare beneficial uses for the water. Idaho Department of Water Resources uses these guidelines in appropriating water. Per water right: Cattle, other than dairy: 12 gallons per day per cow Dairy cattle: 35 gallons per day per cow Horses: 12 gallons per day per horse Mules: 12 gallons per day per mule Hogs: 4 gallons per day per hog Twin Falls Canal Co. General Manager Brian Olmstead — pictured showing a system map in the company’s Twin Falls office Nov. 30 — led the Surface Water Coalition’s negotiations in last year’s historic deal with groundwater users.
First in Time, First in Right
The system used by Idaho Department of Water Resources to allocate water is called the “Prior Appropriation Doctrine.” This is better known as the “first in time, first in right” rule, also used to enforce liens and mining rights. The doctrine is based on an age-old legal principle that predates the U.S. Constitution. The doctrine of Prior Appropriation was first used as early settlers and miners began to develop arid lands in the West. “The first person to take a quantity of water and put it to beneficial use has a higher priority of right than a subsequent user,” Water Resources explains in its publications. The “first in time, first in right” rule is written into the Idaho Constitution. senior groundwater rights. The irrigation district, which covers farm ground in Jerome and Minidoka counties, has filed its own settlement agreement with Water Resources due to its unique position. The hardest pill to swallow for senior water-right holders in the Idaho Ground Water Appropriators, Kostka said, is that the group’s agreement with the Surface Water Coalition “makes all IGWA’s groundwater users equal” no matter what priority
date is associated with their water rights. “It will lower the value of their land,” he said. Kostka knows what IGWA members will have to go through. He went through a similar situation during a drought in 2007. “There wasn’t enough water to irrigate everything,” he said. “I couldn’t make my payments if I had to idle 13 percent of my farm.”
m o n ey fo r t h e Aquifer Planning, Management and Implementation Fund, and $546,100 s p e c i f i c a l l y to implement and enforce the Eastern Otter Snake Plain Aquifer settlement agreement, including hiring four people and funding to install flow meters on about 4,000 wells. Last week, though, Otter proposed boosting the $2 million a year in ongoing funds to $5 million and upping the one-time allotment from $10 million to $16.5 million.
Please see WATER, B4
“I think the governor’s (recommendation) will be very good news for the Magic Valley,” Bell said. “This action will accelerate crucial water recharge efforts and enhance our aquifers so they become truly sustainable resources for Idaho citizens, municipalities, businesses and agriculture,” Sen. Steve Bair, R-Blackfoot, said in a news release. Bair chairs the Senate Resources and Environment Committee and helped to broker the water deal along with Bedke. The extra money isn’t just about the Magic Valley. The Eastern Snake is furthest along in terms of data and projects ready to go, and more will probably be spent there
Sheep: 2 gallons per day per sheep Chickens: 5-10 gallons per day per 100 chickens Turkeys: 10-18 gallons per day per 100 turkeys 1 Household: 0.04 cfs 2 Households: 0.06 cfs 3 Households: 0.08 cfs 10 Households: 0.15 cfs 20 Households: 0.20 cfs 50 Households: 0.33 cfs Hotel with private bath: 60 gallons per room per day Motel with bath: 40 gallons per day per bed space Hospital: 250-400 gallons per day per bed Swimming pool: 10 gallons per day per swimmer Restaurant with bar/lounge, toilets: 9-12 gallons per day per patron School with cafeteria, gym, showers: 25 gallons per day per student Church: 5 gallons per day per person Service station: 10 gallons per day per vehicle Store: 400 gallons per day per restroom Airport: 3-5 gallons per day per passenger Irrigation: A total diversion of 0.02 cfs per acre irrigated, unless the applicant can demonstrate that more is required. For irrigated tracts of 5 acres or less, no additional justification is required for up to 0.03 cfs per acre. For irrigation of public spaces, such as parks and school grounds, Water Resources will authorize diversion of 0.02 cfs per acre times 24 divided by the actual number of hours irrigation each day. For example, a park irrigated for eight hours overnight could divert up to 0.06 cfs per acre.
Source: Idaho Department of Water Resources
initially. But the aquifers elsewhere in Idaho are depleted too, and the state needs to collect data elsewhere and identify recharge projects, said Mathew Weaver, deputy director of the Idaho Department of Water Resources. Otter in his State of the State address urged water users throughout the state to use the Eastern Snake deal as a template for resolving their differences. And Bedke said that, as well as funding, the Legislature this year should pass a resolution recognizing the settlement and the need for similar settlements elsewhere in the state. Bell said taking aquifer money
from the general fund would make it easier for state water officials to plan because they will be able to rely on the money in future years. She credited Bedke and Bair with helping Otter to understand the magnitude of the aquifer’s problems and the need for funding. The alternative, Bell said, would be drying up acres of farmland. “I can’t even imagine what that would do to the whole irrigated structure of southern Idaho,” she said. JFAC is scheduled to take up the Water Resources budget the first week of February. After JFAC sets the department’s budget bill, it moves on to the full Legislature.
B4 • Sunday, January 31, 2016
PHOTOS BY JOY PRUITT, FOR THE TIMES-NEWS
Blocks of aging mozzarella cheese cool in a brine made from ‘cow water’ — water reclaimed from milk during cheese-making — at Jerome Cheese on Jan. 19.
Cheese Plant Reclaims Water from Milk, Eyes Aquifer Recharge MYCHEL MATTHEWS mmatthews@magicvalley.com
JEROME • Jerome Cheese Co. turns milk into cheese. A lot of cheese. But the cheese factory also makes water. Water that’s cleaner than drinking water. Water so clean it’s said to be “polished.” So much water the company hopes to eventually join Idaho’s efforts to recharge the aquifer. The cheese factory is a member of the Idaho Ground Water Appropriators and is subject to the Surface Water Coalition’s 2005 water delivery call. Groundwater is used for the factory’s drinking fountains, sinks and toilets, and for final rinses of equipment. The plant uses no municipal water but draws 400,000 gallons of water each day from its own wells. But the plant has a surprising source of water for its other needs. The company, one of five plants owned by Davisco Foods International, brings in 6.5 million pounds of milk and produces 600,000 pounds of cheese daily. Instead of purchasing municipal water or drawing massive amounts of water from the aquifer, the plant recycles 800,000 gallons of water
ABOVE: This reverse osmosis filtering system at Jerome Cheese separates solids from the water left by cheese making. The reclaimed water is then ‘polished’ by another system, leaving it cleaner than municipal drinking water. LEFT: Jerome Cheese manufactures cheese for 20 hours of each day and spends four hours cleaning the system — using reclaimed ‘cow water,’ a milk byproduct, instead of municipal water. a day pulled from milk during the cheese-making process. This so-called “cow water” is cleaned, polished and reused in the daily four-hour cleaning cycle of the cheese plant and its equipment. Reclaimed cow water is also turned into a brine and used in making mozzarella.
Eventually, when the plant expands, the company hopes to assist in North Side Canal Co.’s recharge efforts, Chief Operations Officer Bill Riebesell said. “We would love to be able to give our excess water to North Side,” Riebesell said during a tour of the plant.
Water
Idaho Irrigation Facts
Continued from B3
Although he farms more acres with groundwater than with surface water, he won’t have to give up any of his water because of A&B’s ongoing recharge efforts. Neither will members of Southwest Irrigation District, said Randy Brown, district manager. Southwest had a previous agreement with the Surface Water Coalition, and the district is working to renew it. “We’re negotiating it now,” Brown said.
The Other 3 Percent Ag producers are not the only water users, but they are, by far, the largest. Municipal and commercial water use makes up only 3 percent of the region’s groundwater pumping, said Rob Williams, lead attorney for the Coalition of Cities, 14 Magic Valley towns that are also negotiating their own deal with the Surface Water Coalition. “Municipal rights are unique, with nuances that need to be treated differently than others,” Williams said. “The cities
STEPHEN REISS, TIMES-NEWS
Shop welder Josh Crandall welds a pivot dive at Sliman & Butler Irrigation on Jan. 20 in Buhl. Farmers across southern Idaho are installing more efficient irrigation equipment to reduce consumption. don’t do a great percent of the pumping, but they need a stable and predictable water supply.” H e ’s w o r k i n g t o make sure their interest is protected. “We’re making progress,” he said. “It’s important for the whole. Cities and agriculture are interrelated. It’s a symbiotic
relationship.” Factories using the municipal water supply process agricultural products grown on farmland outside town. If one suffers, the other does too. Though they aren’t included in the 10-yearold water call, other cities on the Eastern Snake Plain Aquifer from Bliss to
Ashton have joined in the discussion, Williams said. That’s heartening to him; it shows they recognize the magnitude of Idaho’s water crisis. “Cities have to contribute to the overall solution,” he said. “It’s going to take a combination of measures to put more water back in the aquifer.”
93,000: Miles of streams and rivers in Idaho 8,941: Number of named streams and rivers in Idaho 1,478: Number of named springs in Idaho 779: Miles of the Snake River, the longest river in Idaho, from entry at Wyoming border to exit at Washington border 10-60: Averages for annual precipitation in various Idaho locations (in inches) 7.7: Most precipitation in a 24-hour period in Idaho, at Rattlesnake Creek in 1909 (in inches) 37 million: Annual stream inflow to the state (in acre-feet) 75 million: Annual stream outflow from the state (in acre-feet) 3.3 million: Number of irrigated acres in Idaho 3 million: Number of irrigated acres in the Snake River system, including surface water and groundwater irrigation 12.384 million: Reservoir storage capacity (in acre-feet) 2.016 million: Capacity in Dworshak, the state’s largest active storage reservoir (in acre-feet) 100 million: Capacity in the top 100 feet of Snake Plain Aquifer storage (in acre-feet) Source: Idaho Department of Water Resources For her weekly history column, reporter Mychel Matthews has researched the era when irrigation transformed southern Idaho desert into fertile farmland. “I think that people tend to forget that this is still a desert and feel entitled to water that isn’t naturally occurring here,” she says.