ST. PAUL, Minn. -- In some Minnesota lakes, invasive species are limiting the growth of a popular fish, according to a new study of the effects on walleye.

University of Minnesota researchers say the culprits are zebra mussels and spiny waterflea. They found in lakes where these are present, they can reduce the growth size of walleye from 12% to 14%. The species take away zooplankton, a food source for the fish.

Jeff Forester, executive director of the group Minnesota Lakes and Rivers Advocates, said the findings should spur stronger action by the state to prevent the spread of these species.

"What we've been doing -- this kind of emphasis on education and personal responsibility -- that's not getting it done," he said. "I think it's slowed the spread, but it certainly hasn't stopped it."

Forester said he'd like to see the state adopt more stringent boat-inspection policies, such as making it a requirement for people getting an operator's license. The Department of Natural Resources said that, in coordination with local governments, it conducted more than 500,000 watercraft inspections last year, a record number.

Walleye is a favorite fish for anglers and many resorts rely on its popularity for business. Forester acknowledged that it's a difficult balance for the state because boats are helping to spread these species, but many lake communities are dependent on water recreation.

"How do we use the lakes in such a way that they're protected for the future," he said, "and we're protecting the resource, which is not the lake itself, but the quality of life and the economics."

One of the lakes in the study, Mille Lacs Lake, has seen many controversies surrounding walleye fishing in recent years. The DNR has enforced strong limits for anglers so the walleye population can rebound. Some of those restrictions have been slowly lifted as walleye makes a comeback in the popular lake.

The study is online at springer.com.

By Jennifer Oldham for Civil Eats.
Broadcast version by Eric Galatas for Colorado News Connection reporting for the Solutions Journalism Network-Public News Service Collaboration

On a dry, hot day in June, water manager Chris Ivers plunged his hand into San Luis Creek and extracted a tangled mat of weeds that had blocked icy snowmelt from reaching nearby farms. The free-flowing water is a welcome sight in southern Colorado, an agricultural region in the throes of a groundwater crisis.

Ivers, who helps farmers and ranchers in this arid valley use the scarce resource wisely, pointed out the full ditch and green shoots emerging nearby-a byproduct, in part, of a regional experiment in water conservation. "I'm encouraged," he said as crows squawked overhead and mustard grass waved in a slight breeze. "I really haven't been walking out here in a while."

Producers in this sprawling valley, cradled between the San Juan and Sangre de Cristo mountains, have just seven years to replenish overtapped groundwater to levels required by law or face state-mandated well shutdowns. Aquifer storage plunged in 2002 on the heels of a severe drought and hasn't markedly recovered, and much of the region is currently under a federal disaster declaration. Following the 2002 drought, farmers voluntarily created seven governing bodies, called water subdistricts, in the hopes of replenishing two aquifers that make growing food viable here in North America's largest high-altitude desert.

Fields in the San Luis Valley yield two billion pounds of potatoes a year, making the region the nation's second-biggest spud producer. But the valley's irrigation outlook is dire: Water withdrawn by wells exceeds the amount of snowmelt refilling aquifers, and there are more claims to water rights than there is water in streams. The expanse is among the most densely irrigated regions on Earth. To reach that seven-year target, farmers and residents will have to further curtail water use by retiring wells, fallowing fields, and switching to less water-intensive crops; otherwise, the state engineer may intervene and order well curtailments.

That puts Ivers, a program manager for two subdistricts with the Rio Grande Water Conservation District, at the center of difficult decisions about how to use, and conserve, the valley's shrinking water supplies. He is also implementing an innovative project designed to add water back into the aquifer. If successful, the experiment could provide a roadmap for hundreds of farming and ranching communities nationwide whose groundwater stores are dwindling at unprecedented rates.

An 'All Hands' Crisis

At Peachwood Farms, a flat, 1,897-acre expanse at the heart of the valley's groundwater conservation trial, Ivers stood amid fallowed fields bordered by circles of barley and areas being revegetated with native seeds. This patchwork of land marks the personal sacrifices that are keeping the region's agricultural industry-its largest employer-alive.

"If you ask somebody who works in water like me, this looks great," Ivers said, as pronghorn observed him from a distance and a golden eagle circled overhead. The goal, he added, is to significantly curtail water use on the property in order "to help make farming in the rest of this region more sustainable."

In 2022, the nonprofit Colorado Open Lands forged what's known as a groundwater conservation easement with Peachwood Farms' owner. The agreement retired pumping on seven of 12 crop circles over the next decade and halved water use from the remaining five, in exchange for an undisclosed cash payment to the farm and state and federal tax credits. The easement saved 560 million gallons a year and made the aquifer in this part of the valley whole. The unconventional deal ensured that the property's neighbors, like David Frees, will not face well shutdowns, and is an example of the kind of complex solutions needed to keep farms going in the current climate.

"The Peachwood easement allowed us to drop groundwater pumping [in the subdistrict] by 10 percent," Frees said in a recent interview. "Without it, we might have had to curtail everyone's water use by 10 percent."

Instead, the easement allowed the subdistrict's farmers to continue their operations much as they have in the past, said Frees, who runs 60 head of cattle and is president of one of the valley's seven water subdistricts. "As the aquifer fills up, we will have more stream flow extend to other parts of the valley."

Groundwater depletion is by no means unique to this corner of Colorado. Across the U.S., groundwater stores are in the red and dropping fast. Aquifers that farmers rely on for irrigation in California, Arizona, New Mexico, Nebraska, and elsewhere have fallen by dozens of feet since 2002, satellite imagery shows.

Amid this national crisis, the attempts by the farmers in the San Luis Valley to moderate their own use caught the eye of U.S. Senator Michael Bennet (D-Colorado). In 2023, Bennet introduced a bill in the Senate that would increase nationwide funding for groundwater conservation easements akin to the one on Peachwood Farms. Bennet is currently working with fellow senators to include either funding for such programs or a pilot groundwater easement project in the 2024 Farm Bill, said Rosy Brummette Weber, a policy advisor to Bennet.

The Peachwood Farms groundwater conservation agreement has also prompted water managers in overdrafted basins from California to Kansas to approach Colorado Open Lands for information on how to use similar arrangements to preserve water for their growers.

The stakes are high and mounting: The nation's aquifers are dwindling due to rising temperatures, drought, and overuse. Many are not replenishable. Disappearing groundwater threatens the livelihood of crucial agricultural regions like the San Luis Valley, which in turn diminishes the national food system, making the U.S. more reliant on imports. The breadth of the problem prompted President Biden's Council of Advisors on Science and Technology to issue a warning in December, calling the crisis "an all-hands-on-deck moment for groundwater sustainability."

The refusal of some growers nationwide to curb groundwater pumping became evident in May, when Idaho's water agency ordered limitations on the use of wells serving a half million acres of agricultural land, an action described as "the largest curtailment" in state history.

In southwestern Colorado's high desert, producers already till fewer acres, tax themselves to fund fallowing programs, and plant less water-intensive crops. Taxpayers are also footing the bill for a $30 million program approved by the state legislature, in which the Rio Grande Water Conservation District uses funding from the American Rescue Plan Act to pay farmers for retiring their wells.

Yet even after growers here cut pumping by a third, in 2022, water in one of two aquifers fell to its lowest level on record, after extreme heat led to diminished snowpack. Throughout the West, the snowpack of the mountains acts as water bank, with snowmelt filling creeks and streams throughout the summer that help irrigate fields and recharge the aquifer. (The San Luis Valley floor receives only seven inches of rain per year.)

To ensure its aquifers remain sustainable amid an uncertain climate future, the Rio Grande Water Conservation District must permanently withdraw up to 60,000 acres of land from irrigation, about 10 percent of the valley's arable land. After two decades of effort, the aquifers are only a third of the way charged, and frustration with the pace of recovery is high among water managers, producers, and residents.

"The aquifer has not recovered, and we have spent tens of millions of dollars on programs to reduce groundwater withdrawals," said Amber Pacheco, the Rio Grande Water Conservation District's deputy general manager, who oversees irrigators in six subdistricts. (A seventh is operated by the Trinchera Ground Water Management Subdistrict.) Some of the region's subdistricts still haven't seen any aquifer recovery and, she added, they "are in a fight against Mother Nature."

Easements Ain't Easy

Most of the water-saving programs in the valley so far have focused on short-term drying up of land. None have created perpetual groundwater savings or allowed people to keep farming by reducing irrigation over their entire property.

Enter groundwater conservation easements. These are legal tools that restrict pumping on a certain piece of property, and in the arid West and Midwest, they present innovative solutions to aquifer depletion.

Such agreements, like the one forged on Peachwood Farms, allow growers to reduce the number of acres they plant, and thus the amount of water they use, in perpetuity, in exchange for federal and state tax benefits. These agreements can overlap with other solutions. The Rio Grande Water Conservation District, for example, is using money from the USDA's Natural Resources Conservation Service to revegetate easement land with drought-resistant native and non-native plants.

Even so, this promising tool faces challenges to its potential. Chief among them are both a lack of funding for such deals and the fact that appraisers who value conservation easements are unsure how to put a value on groundwater.

"People call me and say they want to put in place a groundwater conservation easement and I say, 'That's great: We have no idea what we would pay you,'" said Sally Wier, groundwater conservation project manager at Colorado Open Lands, who lives and works with producers in the San Luis Valley. "I have people who are 70 years old, and they are trying to decide whether to fallow their land or stay optimistic and continue farming."

Appraisers are adept at valuing traditional conservation easements, in which farmers and ranchers receive tax breaks and grants in exchange for placing deed restrictions on their operations that bar most development. Such deals exploded in popularity over the last decade as agricultural producers sought to stave off big-box stores, self-storage complexes, and residential construction, all of which already consume millions of acres of fertile open space. But applying the same approach to water is tricky.

The Spread of Innovative Easements

In the San Luis Valley, Colorado Open Lands also pioneered a conservation easement program that ties surface water rights to the land. This legal assistance project paired farmers with law students to formalize verbal water-sharing agreements into bylaws. As a result, it preserved a network of centuries-old irrigation ditches known as acequias, whose operators hold the state's oldest water rights.

Similar efforts are underway elsewhere in the West. Just a six-hour drive to the south, near Clovis, New Mexico, lies another arid region desperate to replenish its drought-stricken aquifer.

Here, the Ogallala Land and Water Conservancy is pursuing short-term conservation easements on groundwater rights while it works to secure more funding for perpetual deals. It's a sprint to refill the massive Midwest aquifer, which spans eight states and declined about 17 feet, on average, from when irrigation began in the 1950s through 2017, a U.S. Geological Survey study found.

The diminished water supply requires sacrifices like those made on Peachwood Farms. Eight landowners have forged groundwater leases with the conservancy in which they've agreed to stop pumping from 51 wells, saving about 4 billion gallons a year. Their actions will help secure groundwater supply for Cannon Air Force Base, the city of Clovis, and Curry County-and will protect habitat for endangered species.

To figure out how to fairly compensate the landowners for their water, the conservancy installed a special flow meter on center-pivot sprinklers to calculate total gallons per minute of annual groundwater production, said Ladona Clayton, the Ogallala Conservancy's executive director.

The organization also reviewed crop budgets to analyze harvests over previous years and the herbicides used, as well as insurance, labor, and other production costs, she added. Using about $5 million in federal and state funds, it then annually paid the landowners for 100 percent of the appraised value of their groundwater, allowing them to keep 20 percent of their water. Agreements extend for three years while the nonprofit works to secure further funding for conservation easements.

"These producers who have lease agreements shut off wells in 2022, many that were dry on certain parts of their land," Clayton said. "Now those wells have water-it's music to my ears-they can haul water for their livestock."

Such deals are showing promise, and more will be needed. Extended drought throughout the West is unlikely to abate, nor is demand for water.

Meanwhile, farmers in the San Luis Valley who raise livestock near Peachwood Farms hold high hopes for the groundwater conservation easements. Such deals may eventually play a key part in the ongoing effort to restore the region's aquifer system.

"I'm the fifth generation to farm in the area, and I wouldn't mind doing more deals" like Peachwood, said Pete Stagner, who is vice president of the water subdistrict overseen by Frees and runs 200 head of cattle on a ranch adjacent to Peachwood. "I'm hoping that I can see in my lifetime that our aquifer can get back up to where it was in the 1950s."


Jennifer Oldham wrote this article for Civil Eats.


get more stories like this via email

Clean drinking water doesn't just come from replacing lead pipes. Solutions also rest on Minnesota's farm fields, and this time of year, some rural acreage has been planted with seeds designed to do winter magic before the next growing season.

Cover crops are typically planted going into in a farmer's offseason and are meant to improve soil health before a main crop, like corn, is prioritized the following spring and summer.

Peter LaFontaine, agricultural policy manager with Friends of the Mississippi River, said newer varieties of winter cover crops have come on the scene, potentially changing the dynamics when it comes to profits. On the sustainability side, protecting waterways is still a benefit.

"If you have crops that are providing some more of that natural cover during winter, you wind up with a more resilient system. These crops do a phenomenal job of addressing things like nitrogen loss," he said.

Traditional plants like cereal rye have been helpful with those water quality efforts. But products like winter camelina are getting more attention these days because they have a bigger potential as a dual benefit. They can be harvested for the sustainable jet fuel market. Overall, the cover crop movement still faces headwinds, with an adoption rate below 3% for Minnesota's farmland.

Agriculture experts say Minnesota's harsh winters can be disruptive to cover crops, and it can take time for a producer to fully realize the economic benefits of improved soil quality, such as less flooding in fields.

Anne Schwagerl, western Minnesota farmer and vice president of the Minnesota Farmers Union, has long planted these seeds and is now experimenting with the "cash cover crops." She predicts they'll help with the momentum issue.

"The old adage in farming is don't plant something you don't have a market for. Well, this is something we actually got a market for," she explained.

Schwagerl noted that the biofuels market has a strong appetite for winter camelina. There are federal conservation programs that provide incentives for using cover crops. It's unclear how much extra support will be provided as Congress debates the next Farm Bill.

Despite Minnesota's low adoption rate, more farms were trying cover crops in 2022 compared to 2017. That's according to the Census of Agriculture, released every five years.

Minnesota is credited for having strong wetland protections. But the research community warns the growing presence of factory farms in the Midwest makes it harder to shield these natural resources.

A new report from the Union of Concerned Scientists says 30 million acres of wetlands in the Upper Midwest are at risk of destruction by industrial agriculture and other heavy industries.

The authors said the U.S. Supreme Court's recent decision to strip some federal protections from wetlands accelerates the potential loss.

The Research Director for the Union's Food & Environment program Stacy Woods said because of the role wetlands play in flood mitigation, states in this region are likely to have a harder time limiting damage from a major rain event.

"We know that flooding is a significant issue," said Woods. "It's expensive, and it's getting worse as the climate warms."

While Minnesota's laws might help offset some of the federal impact, the report says neighboring states like South Dakota and Iowa are more vulnerable to wetland loss.

It says priorities of the incoming Trump administration could further complicate protections - but if lawmakers can agree, there could be opportunities in the Farm Bill debate to bolster existing conservation programs.

Wetlands can capture and slow flood waters that threaten homes, but Woods pointed out they do so much more.

"They're often called nature's kidneys, because they provide such a service in cleaning our waterways," said Woods. "But when we dump so much pesticide and fertilizer, and other pollutants onto our fields, that can run off into these wetlands and really impact the wetlands' ability to clean our water."

Meanwhile, researchers say one acre of wetlands provides $745 of flood mitigation benefits to residential homes.

Without wetlands, they say homeowners and taxpayers absorb those costs through the National Flood Insurance Program.




get more stories like this via email