Submitted by Diana Holmes, Pima County Certified Master Naturalist, Cohort 2: Nov 2018
Curious to learn more about the ambitious vision by a collaboration of partners to restore flow to the Santa Cruz River and its tributaries in Tucson, I recently participated in a river walk sponsored by the Watershed Management Group (WMG) River Run Network. We met at Paseo De Las Iglesias Park (Silverlake Road and Cottonwood Lane) and walked in the river bed south to Julian Wash and back. The walk was led by Joaquin Murrieta, WMG’s cultural historian/ecologist.
As a kid in the 1950’s, I can remember the river before it was transformed into a soil-cemented barren channel which typically only flows during storm events. People have thrived along this river bank for thousands of years, and the area is known as the oldest continuously cultivated agricultural area in the U.S. The word Tucson comes from the O’odham word S-cuk Son, literally meaning “at the base of the black mountain.” In 1691, Father Eusebio Francisco Kino made the first of about 40 expeditions into Arizona following along the Santa Cruz River, and Juan Bautista de Anza traveled near the west bank of the river on his 1775-1776 trek to establish San Francisco.
Riparian Ecosystems: In the western United States, riparian ecosystems occur on less than two percent of the total land area. In the arid southwest, riparian ecosystems are now designated as critically endangered. Originally comprising only one percent of the landscape historically, over 95 percent of that riparian habitat has been lost in Arizona.
The Paseo de las Iglesias Environment Restoration Feasibility Study: The study by the US Army Corps of Engineers and Pima County, completed in 2005, evaluated ecosystem restoration, flood control improvements, and river park development along a seven-mile reach of the Santa Cruz River upstream from Congress Street. Planning objectives included increasing riparian wildlife habitat acreage and diversity, providing erosion protection where necessary, and providing passive recreation opportunities. The project was completed in mid-2015 and included gabion bank protection, rip rap and terracing. The river park features five miles of pathways and interpretive signage throughout the site.
This summer, WMG staff crafted their 50-year internal strategic plan for the River Run Network. They state: “The typical three-year strategic plan won’t cut it; so we’re defining goals, strategies and metrics for 5, 10, 25, and 50-year timelines. Intermediary goals and measurable metrics will ensure we reach our long-term goal of restoring Tucson’s heritage of flowing rivers.”
Walking in the riverbed among healthy thickets of young mesquite, native grasses, arrow weed and wolfberry, and with a red tail hawk soaring over head, I was encouraged that a flowing Santa Cruz River would one day be a reality.
US Corps of Engineers Environmental Impact Statement; Pima County Restoration Feasibility Study re Paseo de las Iglesias Park, July 2005
USDA Forest Service, Threats to Western US Riparian Ecosystems, Gen. Tech. Report, 2012
Watershed Management Group Action Bulletin, Nov 2018