Upper South Platte Watershed Characteristics and Features

Upper South Platte Watershed

The regional South Platte Watershed is broken down into three watershed districts; the Upper South Platte Watershed, MIddle South Platt Watershed, and Lower South Platte Watershed. 

The Upper South Platte Watershed is located southwest of Denver, Colorado. The watershed varies in elevation from approximately 6,000 feet to over 14,000 feet above sea level and contains five major municipal and several smaller reservoirs (Coalition for the Upper South Platte Watershed, 2020). 

At approximately 645,00 acres, the watershed covers approximately 525,000 acres of the Pike National Forest, 16,000 acres of City of Denver Water land, 4,000 acres of State of Colorado land, and 100,000 acres of private land. Serving 15 Colorado Counties, The Upper South Platte Watershed is critical to downstream water users as over 80% of the water supplies over 1.5 million people in the Denver metropolitan area. 

The South Platte River is one of Colorado’s finest trout streams. Home to numerous threatened and endangered species, the Upper South Platte River is renowned for its “gold medal waters”.

The river flows through several lakes and reservoirs providing miles of trout fishing opportunities before it reaches the city of Denver. Fly Fishing the South Platte River is considered the best Colorado has to offer by many anglers. Both rainbow trout and brown trout are found in the South Platte River are quite large, averaging over 16 inches but can get much larger. 

Upper South Platte Watershed Elevation

Upper South Platte Watershed Land Ownership

Upper South Platte Watershed Fishing

Big Thompson River

The Big Thompson River is located north of Denver, Colorado - outlined on the adjacent map The Big Thompson River flows for approximately 65-miles, beginning at the Rocky Mountain National Park at an elevation of 11,310 feet until it merges with the South Platte River at an approximate elevation of 4,670 feet (Caring For Our Watersheds, 2018). The Big Thompson River flows into Estes Park and is held in Lake Estes by Olympus Dam. Highlighted on the map in yellow is the path where the water travels once it's released from Lake Estes. The water enters into Big Thompson Canyon and flows through the city of Loveland, Colorado all the way to western Greely, where it converges with the South Platte River. 

The Big Thompson River is a critical resource for surrounding communities and the ecosystem. The Big Thompson River encompasses 900 square miles, contains 173 lakes, and supplies drinking water to 800,000 residents (Big Thompson Watershed Coalition, 2018). Furthermore, agricultural activities use close to 88 billion gallons of water per year supplied by the watershed. Stakeholders work to restore and protect the Big Thompson River due to its value ensuring a sustainable habitat, agriculture, and recreational activities. 

Poudre River

The blue line on the adjacent map outlines the Poudre River. The Poudre river extends for 140 miles, from the headwaters in the Rocky Mountain National Park to the confluence with the South Platte River east of Greely, Colorado.

The Hewlett Gulch and High Park wildfire created several environmental issues for the Poudre River Watershed (Kovecses, 2015). The primary environmental issues consisted of a significant increase in runoff, flooding, sediment erosion, and debris flows. Following the wildfire, each rainfall event carried sediment and ash into the Poudre River (Kovecses, 2015). The runoff stormwater was significant enough to cause road closures in the community. Stormwater runoff transports many contaminants into the river system and degrades the water quality. The Poudre River Watershed is the main source of drinking water for about 300,000 residents downstream. 

The Coalition for the Poudre River Watershed (CPRW) organized and completed multiple successful projects to date. The CPRW implemented more than 300 acres of restoration on both private and public lands (Coalition for the Poudre River Watershed, 2018). They restored a critical stream that was damaged as a result of the fire and flooding. Furthermore, the CPRW worked to mitigate the wildfire risk on approximately 300 acres of forest area that is important to protecting the community water supply. The CPRW developed, implemented, and completed the Upper Watershed Poudre Recovery and Resiliency Plan. Additionally, they are close to completing the Lower Watershed Poudre Flood Recovery and Resiliency Master Plan. The efforts of the CPRW were recognized and therefore awarded the 2014 and 2016 Larimer County Environmental Stewardship Award (Coalition for the Poudre River Watershed, 2018).