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Santa Cruz River Management Plan

For more information contact:
Evan Canfield, P.E., CFM
(520) 724-4600

The purpose of the Santa Cruz River Management Plan is to develop a management strategy to balance flood risk management, drainage infrastructure protection, water resources, recreation, education opportunities, public safety and riparian habitat preservation for the Santa Cruz River from the Santa Cruz County Line to the Pinal County Line.

Efforts are divided up by reach as follows:

Santa Cruz County Line to the San Xavier District (Pima Mine Rd.) – This effort is directed to better understanding the complex flood flow, so that flood risk is better identified and as a basis for understanding future proposed actions in the River and the adjacent properties.

San Xavier District to Grant Rd. – This effort is directed at reducing flood risk while engaging in opportunities for improved habitat and recreation in this largely bank-protected reach.

Grant Rd. to Pinal County – The District is developing a multi-objective management plan.  To date the plan has developed a detailed assessment of existing conditions (flood risk, repeat maintenance).  With the assistance of representatives of the jurisdictions and other decision-making stakeholders, the District is developing a series of built, and dispersed alternatives for future improvements.

Project Documents and Events

October, 2020 Project Update
December, 2019 Project Update
Read the latest Living River Annual Report – Charting Santa Cruz River Conditions Northwest Tucson to Marana – 2019 Water Year.

Learn about Dragonflies on the Santa Cruz River at Dragonfly Day – October 3, 2020

Public Survey: Providing Information and Soliciting Input on Proposed River Improvements - Grant Rd. to Pinal County

Sonoran Institute has created an online survey to support the Pima County Flood Regional Control District as they consider future improvement projects that will balance flood risk management, recreation opportunities, public safety, and riparian habitat restoration. The projects incorporated preferences and priorities for the Santa Cruz River identified by the public in a previous survey, as well Pima County’s goals for floodplain management in the recently-adopted Floodplain Management Plan. Over the last year, the Flood Control District and stakeholders have identified a wide-ranging set of improvements that can be implemented along the river with future budget allocations.
  
Now we need your help!!

Please take this interactive survey to give us your thoughts on projects to improve the Santa Cruz River to better reflect the needs, desires, and values of the community.

Santa Cruz County Line to Pima Mine Rd.

The District has prepared a detailed flood map using a cutting-edge hydraulic model for floodplain mapping, allowing the District and stakeholders to better understand flood risk in this highly complex flood area.  This project began a new phase of updating the FEMA floodplain maps in September, 2020 for this reach of the Santa Cruz River.

Pima Mine Rd. to Grant Rd.

The District has removed sediment and improved conveyance from Silverlake Rd to Grant Rd.  The District has collaborated with the City of Tucson on the Santa Cruz Heritage Project. The District also cut notches in the grade control structures in the Heritage Reach in order to focus the flows where they can sustain improved habitat. 

Grant Rd. to Pinal County Line (Trico Rd.)

The purpose of this phase of the project is to develop a management strategy to balance flood risk management, drainage infrastructure protection, water recharge, recreation, education opportunities, and riparian habitat preservation for the Santa Cruz River from Grant Road to Trico Road.

CONTENTS

Effluent-Dependent Santa Cruz River

Background

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 effluent-dependent Santa Cruz most notably Pima County’s Regional Optimization Master Plan (ROMP) and the Loop Recreational Trail. Using the successful EPA-funded “Living River” series implemented by the Sonoran Institute as a model, Pima County and the Pima County Regional Flood Control District developed a monitoring strategy and similar reporting tool for the Santa Cruz River in Northwest Tucson and Marana with the assistance of a Technical Committee of experts and stakeholders.

The Regional Optimization Master Plan (ROMP) upgraded the two major regional wastewater treatment plants discharging to the effluent-dependent Santa Cruz River, which began discharging improved water quality to the effluent-dependent Santa Cruz River in 2013. Pima County has been evaluating the effect of effluent water quality upgrades as a result of ROMP on a wetland health.

Living River Reports

Other project publications can be found in the tabs below.  Resources and other reference materials can be found at the Lower Santa Cruz River Research Papers and Reports page.

A Living River - Charting Wetland Conditions of the Lower Santa Cruz River

Since the upgrades, A Living River annual reports have documented profound improvements in the wetland health along the effluent-dependent Santa Cruz including:

  • Improved river water quality, including lower ammonia and biochemical oxygen demand with higher dissolved oxygen, improving conditions for aquatic life.
  • Improved water clarity.
  • Broadened diversity of macroinvertebrates, including increased presence of species sensitive to water pollution.
  • Five fish species now thrive, whereas none lived in most river reaches before.
  • Citizens observed more than 221 bird species; Sandhill Cranes sighted recently.
  • Sustained recharge has risen to about 36,600 acre-feet per year, nearly double the pre-upgrade rate, despite an 8% reduction in volume of water released to the river. 
  • RWRD’s odor measuring technology shows little to no odors leaving the wastewater facilities’ property under normal operating conditions after WRF upgrades; prior to upgrades, odors were an ongoing complaint of nearby residents and river visitors.
  • Increased linear park public use, mainly by pedestrians and bicyclists.
  • More than four thousand people have attended public education and outreach activities featuring the Living River.

In short, Living River annual reports have documented public benefit of a substantial investment in improved infrastructure, turning the river corridor from a liability to community asset.

Watch a short video on the project.

Historical Conditions Report

The report on the Historical Conditions of the Effluent-Dependent Lower Santa Cruz River was completed in March 2013 to identify baseline and past history of the effluent-dependent reach.  The report covers stream discharge and loss, channel morphology, vegetation, macroinvertebrates and water quality.  It projects changes that the team thought might occur after treatment plant upgrades.

Conservation Effluent Pool (CEP)

A CEP was granted to the District which will help to preserve, protect and enhance riparian vegetation and aquatic habitat within the Santa Cruz River.

 

Project Updates

A summary of the project progress is now available. This project is in the Alternatives Development Stage.  A stakeholder meeting is scheduled for May 21, 2020. In December 2019, the project team held three open houses along the river to discuss public interest and priorities for the Management Plan.

Project Location

The approximate limits of the Santa Cruz River Management Plan (Grant to Trico) are shown on the project reach map.  The lateral extent along this alignment is limited to locations where RFCD has operational control (ownership or maintenance responsibilities).

Project Description

The lower portion of the Santa Cruz River in Pima County constitutes the County’s principal wetland habitat. Comprised of routine discharge from the Regional Wastewater Reclamation facilities thereby creating improved wetland ecosystems and floodplain aesthetics along the lower Santa Cruz River. This project, with the assistance of experts and stakeholders, will provide strategic planning and planning-level alternatives to help balance environmental, water resource, recreation, education, and flood hazard needs, desires, and concerns.

The Pima County Regional Flood Control District (District) is seeking professional consulting engineering (Consultant) services necessary for developing a Santa Cruz River Management Plan, which will identify flood hazard areas and drainage problems leading to cost-effective, multi-benefit solutions to alleviate or manage flooding in the study area.

Project Elements

Phase 1 – This phase, initiated in February 2018 and completed in October was devoted to existing conditions assessment. Three reports were prepared during this phase:

1.) Existing Conditions Report – This report documents drainage complaints, land ownership, maintenance responsibility, previous studies and projects that have been done in this part of the Santa Cruz River.
2.) Infrastructure Assessment and Maintenance Evaluation Report – This report evaluated the state of infrastructure in the Santa Cruz including the state of the soil cement bank protection and conveyance capacity of the River in a 100-yr flood.
3.) Technical Data Support Notebook for floodplain mapping – This report identified the flood risks along the corridor associated with the 1% annual chance (100-yr) flood and 0.2% chance (500-yr) flood.


The findings of these three reports were used to understand baseline conditions for three sub-reaches of the Santa Cruz River because of the distinctive condition of each sub-reach.

• Grant Rd to Ina Rd Sub-Reach
• Ina Rd to Avra Valley Rd Sub-Reach
• Avra Valley Rd to Trico Rd Sub-Reach

The District will collaborate heavily with the affected jurisdictions, and presented the results of Phase 1 to the Marana Town Council in a study session on September 24, 2019.

Two Stakeholder Engagement meetings were held during Phase I.
May 31, 2018
May 22, 2019


Phase 2 – Will develop recommended alternatives and an implementation plan. Phase 2 began in October, 2019, and is expected to be completed in Spring, 2021. The Timeline for Phase 2 can be found HERE

Public Involvement

The District will participate in community engagement throughout the project.  Initial insights will be from a community engagement effort of priorities, values and concerns being conducted by the Sonoran Institute, which has collected over 500 responses from an on-line survey. 

Public Meetings: Open houses for the public will occur in each of the subreaches at the following times during the project:
• At initiation of the project to inform the public and solicit input on problems and opportunities (December, 2019)
• To present and discuss possible alternatives (Spring, 2020)
• To present recommended alternatives (Spring, 2021)

Stakeholder Alternative Working Groups: Help develop an appropriate set of reach specific alternatives
Representation includes
• Community Groups
• Community Water Coalition of So. AZ
• Jurisdictions
• Landowners
• Public Safety
• Water Owners
Stakeholder Meetings: These will include representatives of all interested organizations to review the possible alternatives and implementation plan.