Health Alert:   COVID-19 Transmission Level:   HIGH   More information
Get vaccinated.
Pima County Government Logo
  • Increase font size
  • Decrease font size
  • Print
  • RSS

Lower Santa Cruz River Living River Project


Regional Optimization Master Plan (ROMP) will upgrade the two major regional wastewater treatment plants discharging to the Lower Santa Cruz River (LSCR). Pima County received a grant from U.S. Environmental Protection Agency (EPA) to evaluate the effect of effluent water quality upgrades as a result of ROMP on a wetland in the LSCR. This website includes resources collected for the project.

Project Overview

The Lower Santa Cruz River in northeastern Pima County is Arizona’s longest effluent-dependent river and creates the County’s principal wetland habitat. Significant steps are underway to improve wetland ecosystems along the Lower Santa Cruz River (LSCR), most notably Pima County’s Regional Optimization Master Plan (ROMP). Using the successful EPA-funded “Living River”  series implemented by the Sonoran Institute as a model, Pima County has developed a monitoring strategy and similar reporting tool for the Lower Santa Cruz River with the assistance of a Technical Committee of experts and stakeholders. The project will provide numerous environmental outcomes including increased understanding of wetland conditions, and improved public understanding of the value of wetlands. 

The Sonoran Institute leads this project and provides reports and other information on their website, which we encourage you to visit for more information. The Living River search page will take you to directly to a search page containing reports, blog posts, and more related to the Living River work along the Santa Cruz River.

2019 Water Year Publication

A Living River: Where Community and Nature Meet, Charting Santa Cruz River Conditions from Northwest Tucson to Marana – 2019 Water Year

Press Release

Checking in the on the Health of the Santa Cruz River, NPR 12/18/2020

Project Publications

Other project publications can be found in the tabs below. Other resources can be found at Research Papers and Reports page

Technical Reports


Lower Santa Cruz River Riparian Vegetation 2015 Survey Report, Final
Technical Report, Santa Cruz Monitoring and Sediment Transport Study  (Final Draft)


Lower Santa Cruz River Macroinvertebrate Analysis and Stream Assessment, 2014 Survey Report, Final
Lower Santa Cruz River Riparian Vegetation 2014 Survey Report, Final


Lower Santa Cruz River Riparian Vegetation 2013 Survey Report, Final

Additional monitoring data may be available. Please visit the Sonoran Institute’s Santa Cruz River Living River website or contact Sandy Steichen, Principal Hydrologist, Pima County Regional Flood Control District, (520) 724-4600.