Nebraska officials are moving ahead on a roughly $628 million canal/reservoir project that will finally enable the state to fully claim its fair share of water flows from the South Platte River, as dictated by an agreement with Colorado approved more than a century ago.
The canal will transport water from the river, which originates in Colorado, to one or more reservoirs in the southwest corner of the state. The water then will be released as needed during irrigation season, says Jesse Bradley, interim director of the Nebraska Department of Natural Resources.
The end goal: Supplement the rapidly diminishing flow of water in the South Platte River, which eventually merges with the North Platte River and forms the Platte River, a vital source of water and economic vitality for approximately 75% of the state’s residents.
The project will enable Nebraska to finally utilize water rights it was granted back in 1923 under the terms of the South Platte River Compact. The agreement, which regulates the use of the river’s water by both Colorado and Nebraska, resolved a lawsuit over water usage brought by Nebraska’s Western Irrigation District more than a century ago.
The waterway, called the Perkins County Canal, is expected to deliver anywhere from 75,000 to 175,000 acre-feet of South Platte River water per year, Bradley says.
In 2022, the Nebraska state legislature approved funding for the project, which now is in the design phase. The NeDNR will manage the project in partnership with water-related stakeholders that operate irrigation districts and hydropower facilities. Preliminary plans call for construction to begin in 2028 and conclude in 2032.
“It’s a very significant project,” Bradley notes. “If it’s not the largest state investment in an infrastructure project, it’s right near the top.”
Complex solution
Following the provisions of the compact, the canal will start on the south bank of the South Platte River, just southwest of Ovid, a small town tucked in the corner of northeastern Colorado. Roughly 17 miles of the canal will lie in Colorado, then pass through 20 to 40 miles of southwestern Nebraska before ending in one or two reservoirs, Bradley explains.
While the final size of the reservoir(s) has yet to be determined, Bradley expects total capacity of 10,000 to 100,000 acre-feet of water.
“We’re also looking at using other facilities to store water in other parts of the Platte River basin,” he says.
The exact path of the canal still is under consideration. But it’s expected to be about 40 to 60 miles long. To create a canal corridor, Nebraska will have to buy approximately 1,000 acres of land in Colorado, which is allowed under the compact, and around another 4,000 to 6,000 acres in Nebraska. The majority of the Nebraska land will be used for the reservoir or reservoirs, he says.
As currently envisioned, one leg of the canal will branch off the South Platte River and carry water east by gravity into the west side of a reservoir. A second leg, which will connect to the east side of the reservoir, will travel east before heading north and connecting with the South Platte River along its southern bank.
Going with the flow
During nonirrigation season, which runs from Oct. 15 to April 1, the canal will be allowed to carry South Platte River water at a flow rate of 500 cubic feet per second plus any additional available flows. A gauge located in the river, near the canal entryway, will measure the flow.
Officials will control the amount of water that enters the canal via a concrete diversionary structure that will be built across the river, just past the canal entryway. The structure will include gates that can be closed to restrict water flow to the point that it pools up high enough behind the structure to empty into the canal, he explains.
The gates also can be opened to allow the river to bypass the canal and flow to downstream users. Furthermore, the canal entryway will include a gate to restrict flow into the canal as needed.
Water stored in the reservoir then would be released as needed during irrigation season, which runs from April 1 through Oct. 15.
“We also are allowed to capture surplus flows during irrigation season as long as other water rights are satisfied,” Bradley says.
Valuable resource
The primary use of the water will be for agricultural irrigation, but it’s also critical for many secondary users, Bradley points out.
“First we need to shore up those irrigation flows,” he says. “But integrated with that use are things like cooling water needed for the state’s largest electricity-generating plant, located near Sutherland (The Gerald Gentleman Station).”
“There also are a number of hydropower units the water passes through,” he continues. “And that water will also help stabilize water levels in Lake McConaughy, a reservoir whose releases are driven by how much water comes from the South Platte River.”
Furthermore, the South Platte River supplies about 30% to 40% of the water that forms the Platte River, with the remainder supplied by the North Platte River.
Sustained South Platte River flows also are critical to protecting a large and significant wildlife habitat for endangered species along the Platte River, not to mention that Omaha and Lincoln, the state’s largest cities, rely on the Platte River for drinking water, Bradley says.
“South Platte River water benefits and protects more than $1 billion in existing water-related infrastructure,” he says. “So losing that flow would be significant, especially when you consider that about 75% of the state’s population lives along the Platte River corridor.”
Long time coming
It’s in Nebraska’s best interests to build the canal sooner rather than later because under the provisions of the 1923 agreement with Colorado, it can only start claiming South Platte River water rights after it’s built.
“Without the canal, Nebraska can’t secure the water it has a right to use,” Bradley says.
Furthermore, the longer Nebraska waits, more land development will occur in Colorado’s Front Range region, east of the Rocky Mountains foothills. That, in turn, means more usage of South Platte River water by parties with so-called junior water rights, which are subservient to Nebraska’s rights — but only after the canal is built, he says.
Private organizations tried to build a canal more than a century ago, but ran out of money. In fact, portions of previous canal construction efforts dating back to 1891 remain visible along Interstate I-76 near Julesburg.
Without funding, the project lay dormant for decades. But significant reductions in South Platte River flows during the last 20 years or so, which are putting Nebraska’s water entitlement in jeopardy, spurred state officials to revive the project.
How much has the South Platte River’s flow diminished? During the 1970s to around the early 2000s, flows during the nonirrigation season averaged around 620 cfs. But in the last 200 years, those flows slumped to about 335 cfs — a drop of nearly 45%. And much of that loss is attributed to use by parties with junior water rights, Bradley says.
Other factors prompted action, too, including changes in climate and weather patterns and the aforementioned concerns about continued real estate development in Colorado that requires more and more South Platte River water. Colorado isn’t going to limit its water use unless the canal is built, Bradley says.
“We’ve been watching South Platte River water flows for years,” he explains. “We see flows are declining and we also see plans in Colorado that will require more development of flows that will continue that decline.
“The only way to stop that is to utilize the South Platte River Compact, which specifies that the canal would secure Nebraska’s entitlement to flows on the South Platte River.”
Multigenerational impact
Initially, resurrecting the project prompted threats of lawsuits, according to newspaper reports. But, in the end, the agreement embedded in the compact prevailed.
“We’ve worked with Colorado on other interstate compacts,” Bradley says. “Compacts are very important to each state — they allow states to protect interstate water flows.
“Colorado officials certainly recognize we have a clear right to move forward with this project and protect future flows of the South Platte River,” he continues. “Certainly there are Colorado landowners who have some concerns, but we continue to have dialogue with Colorado state officials and do this in a way that’s on the up-and-up — working with each other and being transparent about how we move forward.”
In the long run, the canal, which will be managed and operated by the NeDNR, will be essential to preserving and enhancing Nebraska’s economic development and building up its water resiliency, not to mention bolstering the health and welfare of its residents, Bradley says.
“Certainly all of those boxes will be ticked,” he says, noting that water canals have been instrumental to building regional economies statewide since the late 1880s. “Those investments have paid for themselves many times over and still provide great value today.
“This project will have a multigenerational impact,” Bradley adds. “Making this investment today will preserve these water flows for the future and will set Nebraska up with infrastructure that will keep our agricultural base moving forward.”
