What is Colorado’s Obligation Under the Platte River Recovery Implementation Plan?
There are four endangered species in the Platte River in Nebraska, the interior least tern, whooping crane, piping plover and pallid sturgeon. To protect these species there needed to be flow protections implemented on the contributing drainage basins, i.e., the South Platte River in Colorado, the North Platte River in Wyoming, and the Platte River below the confluence in Nebraska through south-central Nebraska. The result was The Cooperative Agreement for Platte River Research and Other Efforts Relating to Endangered Species Habitats Along the Central Platte River, Nebraska, sometimes referred to as the Tri-State Agreement, see LWS 07/06/2022 blog.
Pallid Sturgeon
As a result of the Tri-State Agreement and through a number of subsequent actions, the Platte River Recovery Implementation Plan (“PRRIP”) was born.
The PRRIP has three main elements, to:
increase stream flows at critical times of low flow in the central Platte River through retiming and water conservation/supply projects;
enhance, restore and protect habitat lands for the target bird species; and
accommodate certain new water-related activities.
Whooping Cranes. Photo 4177210 © Norman Bateman | Dreamstime.com
To achieve the flow objectives, each state has the responsibility to maintain water use and associated river depletions consistent with the estimated use as of July 1, 1997. For Colorado, the project to meet compliance with the Tri-State Agreement flow targets is the Tamarack Project.
The Tamarack Project is located in northeastern Colorado near the town of Crook, between Sterling and Julesburg in Logan County. The Tamarack Project diverts water from the South Platte River through wells when the water right is in priority, i.e., at times when there is excess water in the river beyond the demands of senior water rights users. This water is then stored in off-stream ponds, located at varying distances from the South Platte River. The project effectively manages the timing and amount of recharge back to the river so target flows from Colorado to meet endangered species requirements in Nebraska are met.
Interior Least Tern. Photo 42652307 / Interior Least Tern © Howard Nevitt, Jr. | Dreamstime.com
This managed aquifer recharge is achieved through the pumping of alluvial groundwater into ponds that have are unlined so they will recharge the aquifer. The amount and timing of water delivery to a specific pond is controlled by when and how much water needs to be retimed to the South Platte River. Water that is stored, then recharges the alluvial aquifer at some distance from the river channel, and this water then slowly moves back towards the South Platte River where it provides retimed water supplies to the river to meet Colorado’s obligation to supplement flows during critical period when target flows need to be met in the Central Platte River Basin. By storing water at various locations from the South Platte River, the timing back to the South Platte River can be controlled to match to the target flow needs. The Tamarack project seeks to provide an average of 10,000 acre-feet per year to Platte River flows.
To implement the Tamarack project and to assure that Colorado meets the maintenance of the 1997 water use and depletions, the South Platte Water-Related Activities Program (“SPWRAP”) was established. This program allows for new development of water supplies in the South Platte River Basin by providing members of SPWRAP with compliance under the Endangered Species Act. Membership in SPWRAP allows the development of new water supply projects, with associated new river depletions as, through membership, the Tamarack project can continue to provide compliance with the necessary deliveries of water to Nebraska. Additional information on SPWRAP can be found at http://cospwrap.org/ .
Piping Plover
The PRRIP has now been in operation for approximately 15 years and is proving to be a successful program for retiming flows to help protect the endangered species. I would be remiss if I didn’t acknowledge the first Executive Director of the PPRIP, Mr. Jerry Kenny, who was a friend of mine, and was so tragically taken from us at much too early an age. Jerry served as the Executive Director of the PRRIP for over a decade and helped set the successful course for the PRRIP. He is greatly missed.
LWS is currently working on a collaborative municipal-agricultural joint use project, the Platte Valley Water Partnership (see LWS September 2020 blog series on an “Integrated and Sustainable Water Management Plan for a Growing City - A Case Study” Part 1, Part 2, Part 3). This project will protect the yield of the Tamarack project, as well as Colorado’s commitment under the South Platte River Compact. If you have any water rights or surface water hydrology issues, feel free to give us a call (303-350-4090) or an email.
Bruce Lytle, P.E. bruce@lytlewater.com
Chris Fehn, P.E., P.G. chris@lytlewater.com
Ben Bader ben@lytlewater.com
Anna Elgqvist, E.I. anna@lytlewater.com
