Poudre Headwaters Project

PHP (“the Project”) is a collaborative effort between multiple State and Federal agencies along with some non-governmental organizations, such as the Rocky Mountain Flycasters Trout Unlimited Chapter (RMFTU), Colorado Trout Unlimited (CTU), and Trout Unlimited (TU) at the national level, to restore greenback cutthroat trout to a large portion of the upper Cache la Poudre River watershed.

Greenback cutthroat trout (Oncorhynchus clarkii stomias) are not only Colorado’s state fish, but they are also a critical part of Colorado’s natural heritage as the only salmonid native to the South Platte River Basin. They are now confined to less than one percent of their historic range and are federally listed as “threatened” under the Endangered Species Act.

Several factors contributed to the decline of greenback cutthroat trout within their native range. Most prominent of these was the introduction of non-native salmonids (such as brook trout, rainbow trout, other subspecies of cutthroat trout, and brown trout) within waters that once only held greenbacks, along with habitat destruction and water quality degradation from extractive industries such as logging and mining.

37 river miles and 106 lake acres (Long Draw Reservoir).

Generally, the timeline is fluid and depends on several variables, but the goal is to complete much of the Project within the next few years and there is a hard deadline of 2047 to complete the entirety of the Project.

There is a sum of money held in trust for the Project ($1.25 million dollars which is expected to cover around fifty percent of the expected total cost) that emanated from a settlement related to litigation over re-permitting the operation of Long Draw Reservoir. However, much of the Project is also funded by donors through CTU and RMFTU.

The Project involves collaboration with multiple State and Federal agencies including Colorado Parks and Wildlife, the U.S. Forest Service, the National Parks Service, the U.S. Fish and Wildlife Service and the Bureau of Land Management.

The Project will require five total barriers. There will be two permanent barriers - one man-made barrier on the Grand Ditch (to keep greenbacks from migrating across the Continental Divide to where they are not native) and one mostly natural barrier at the falls (known by whitewater recreationists as “starter fluid”) on the upper Cache la Poudre itself (to prevent non-native salmonids from re-invading the Project area). Additionally, there will be three temporary barriers (all of which will be removed during the final stage of the Project to reconnect habitat) - one on Hague Creek above its confluence with the Cache la Poudre; one on the Cache la Poudre itself above the confluence with Hague Creek; and one on Corral Creek above its confluence with the Cache la Poudre River.

Rotenone is an Environmental Protection Agency restricted use ‘fish toxicant” derived from organic sources that disrupts the respiration of fish. Applicators must be licensed, follow instructions on the product label, and are legally obligated to adhere to the Standard Operating Procedure Manual. The application of rotenone is intended to kill all fish within a treated area prior to restocking.

Non-native salmonids, like brook trout, have been shown to outcompete and prey on greenback cutthroat trout (to the point of elimination if unchecked), especially in the first couple of years of a cutthroat’s life. Mechanical removal methods (such as electrofishing and netting) are ineffective and inefficient for removing non-native salmonids on the scale required by the Project. Further, mechanical removal of non-native salmonids would be impractical given the rugged, remote terrain of the Project area. Rotenone treatment is the only completely effective and economical way to be sure non-native salmonids have been removed from Project waters before the reintroduction of greenback cutthroat trout.

No. While rotenone may temporarily impact some aquatic insect populations, steps are taken in terms of timing of treatment to avoid a significant impact and historical use of rotenone has not led to long-term population declines in insects (populations typically recover by the year after treatment). Any potential impacts to amphibian populations are also mitigated via the timing of rotenone applications; for example, because rotenone only affects gill-breathing animals, agencies are treating waters after amphibians are known to metamorphose (change from their gilled, larval stage to lung-breathing adults). At the concentrations that are applied, birds and mammals, including humans, will not be negatively impacted by treatment. Rotenone also does not move up the food chain when animals eat dead fish. To prevent impact to waters outside of a project area, rotenone is detoxified via an application (usually below a barrier) of potassium permanganate, which oxidizes any remaining rotenone. Moreover, any residual rotenone within an application area naturally breaks down in the environment through exposure to sunlight and oxygen.

Yes, absolutely. The goal of the Project is not to eliminate angling opportunities for all other salmonids other than greenback cutthroat trout, but rather, to create a refuge for the State’s fish within the Project area and enhance the diversity of fishing opportunities in the wider region. Brown trout, rainbow trout, brook trout, other subspecies of cutthroat trout, and even grayling (Joe Wright Reservoir) will still be in ample supply for angling opportunities across the region outside of the Project area. These opportunities will continue to include a diversity of angling experiences available throughout Rocky Mountain National Park, surrounding lakes, and in the Poudre River itself below the Project area (along with many of the river’s tributaries). With the establishment of a fishable greenback cutthroat trout population in the upper Poudre River watershed, the region will become a diverse and truly one-of-a-kind angling destination. 

Stocking of greenback cutthroat trout will occur first in areas above temporary barriers once they have been treated with rotenone and it has been confirmed that those sections are free of non-native salmonids. Once the entire Project area has been treated and confirmed to be clear of non-native salmonids, then restocking will be completed for the remaining Project area.

Yes. Project plans anticipate allowing for regulated catch-and-release fishing following the establishment of greenback trout within the Project area.

One of the goals of the Project is to restore a quality native greenback trout fishery to Long Draw Reservoir and provide a one-of-a-kind opportunity for Colorado’s angling public to catch and release the State fish. The Reservoir would also be a source of greenback offspring for reintroduction efforts throughout the South Platte River Basin.