The South Platte Salinity Stakeholder Group, which represents municipal, industrial, agricultural, and environmental interests, has identified the need for a basin-wide assessment of current salinity conditions. This project aims to summarize the state of knowledge on surface and groundwater salinity in the SPRB. Specific objectives are to (1) assess existing information on the nature and extent of surface and groundwater salinity and its impacts on municipal water supply/treatment and irrigated agriculture in the SPRB; (2) identify key problems and issues caused by rising salinity that are currently affecting representative stakeholders; and (3) organize the collected information into an online portal widely accessible to stakeholders. This will enable planning for targeted applications of monitoring, treatment, and remediation technologies at identified salinity hot spots within the SPRB.

1. Farmer Engagement
   • Identify farmers and farmland available for long-term salinity characterization – target of 100 monitoring locations
2. Farm visits and windshield surveys
   • Interviews with producers
   • Field observations of soil conditions, pumping wells, and ditches
3. Spatial database and evaluation
   • Compile data collected during field reconnaissance in spatial database
   • Identify long-term monitoring sites

The goal of this project is to initiate a systematic investigation that will lead to a reliable definition of the problem of water and land salinization in Colorado’s South Platte River Basin (SPRB), forming a sound basis for a search for effective solutions.  This goal is to be accomplished through the following objectives:

1.  Assess existing information on the nature and extent of SPRB salinity and its impacts;

2.  Develop a rationale and plan for extensive data collection to enhance the characterization of salinity and its impacts and to support a search for effective solutions; and

3.  Initiate the gathering of the required additional data.

Outputs will include (1) established working relationships with stakeholders, experts, and agencies; (2) a written report summarizing available salinity information and laying out plans for a thorough data collection campaign; (3) a SPRB salinity data platform; and (4) an emerging monitoring network and some preliminary collected data.

Information gathered in this project will help water users and managers understand the state of salinity problems in the SPRB and the vulnerability of the agricultural economy to this growing water quality concern.  It also will form a springboard for discovery and implementation of effective solutions, leading to diminished land and water salinization and increased crop productivity.

To promote sustainable agricultural practices in Colorado’s South Platte River Basin (SPRB), it is imperative to understand the soil salinity status and its relationship with water resources salinity and other influencing factors. In this research project, we plan to use Landsat 5, 7 and 8 multispectral images to map estimated actual crop evapotranspiration, crop water stress, crop yield, and soil salinity levels (electric conductivity, dS/m) across the SPRB over a historic period of 20 years. The information gained from these maps will aid in the identification of agricultural lands with different levels of salinity impact. We will focus mainly on corn and alfalfa fields because of their large extent in the SPRB and because of their deep root systems and response to salinity. Data on factors potentially contributing to salinity (irrigation methods, agronomic practices, soil types, irrigation water salinity, and geology) will be garnered from existing publications and on-going surveys being carried out by related projects. The information obtained from maps and the datasets shared by these collaborators will be merged into a Geographic Information System (GIS) to explore potential cause and effect relationships. The elaboration of the different salinity maps and apparent rates of salinization will assist in identifying key locations within the SPRB for more detailed monitoring in future projects. Thus, the outcomes of this project will help define a long-term research effort and publications will be a channel to educate stakeholders on the status of agricultural land salinization, its likely causes, and prospects for mitigation.