South Platte Salinity
Stakeholder Group

A cooperative effort that integrates stakeholder concerns, needs, and priorities to understand the sources, loads, trends, and impacts of salinity in the South Platte River Basin.

Read their research

Sewage effluent from Denver metro wastewater treatment facility creating a foam on the South Platte River near a bridge. The South Platte Salinity Stakeholders work to understand these types of effects.

Group members

Formed in 2020 out of the recognition that salinity in the South Platte River Basin needs regional dialogue and coordination. The South Platte Salinity Stakeholder Group is a cooperative effort representing interests from the following groups:

Agriculture
Municipalities
Water suppliers
Water treatment
Researchers

Focusing on the South Platte River and its tributaries from Waterton Canyon to the Colorado/Nebraska state line, the group, facilitated by the Colorado Water Center, works to integrate stakeholder concerns, needs, and priorities to improve our understanding of the sources, loads, trends, and impacts of salinity in the South Platte River Basin.

Salinization in the basin

The South Platte River Basin (SPRB) is the most populous and agriculturally productive basin in Colorado. Approximately 80% of Colorado’s population resides in the SPRB and is expected to increase from 3.5 million in 2008 to 6 million people by 2050.

The Basin also has the greatest concentration of irrigated agricultural lands (~ 800,000 acres) that account for approximately 72% of Colorado’s agricultural output. Emerging evidence reveals that the SPRB, like many other intensively developed and irrigated regions worldwide, is experiencing salinization.

A recent study of South Platte River salinity revealed that annual average salinity in 2018 was 569 mg/L (Total Dissolved Solids, TDS) in the Denver Metro area (upstream part), increasing to about 700 mg/L from the Metro area to Kersey, CO, and continued to increase to 1,165 mg/L near Julesburg, CO (near the Colorado-Nebraska State line).

A river and canal with water diversion infrastructure

Need for understanding

The U.S. Environmental Protection Agency has a secondary drinking water standard of 500 mg/L for TDS, which is also the salinity level at which salt sensitive crops like beans, carrots, and onions may experience yield reductions. Many other crops may experience yield reductions in the 1,000 to 2,000 mg/L TDS range (e.g., corn and alfalfa).

In addition, treating municipal water with high salinity concentrations can be costly due to the technology and brine disposal required. The consensus among stakeholders and experts is that salinity sources, loads, trends, and potential impacts need to be better understood and addressed in the municipal, agricultural, water-supply, and environmental context of the SPRB.

Read about the ongoing research

Meet the Stakeholders