Santa Cruz – Middle

To provide comments on this watershed for consideration in the Floodplain Management Plan, contact Greg Saxe
Planning Manager
(520) 724-4633.
The portion of the watershed identified as the Middle Santa Cruz River begins near the northern boundary of the San Xavier District of the Tohono O’odham Nation near Martinez Hill. The Middle Santa Cruz River is where the confluence of its largest tributaries, the Cañada del Oro Wash, Rillito Creek, and the Julian Wash, occur. Excluding these tributaries, the watershed is comprised of 150,746 acres mostly coming from the east slope of the Tucson Mountains and the west portion of Tucson. The portion of the Santa Cruz River through the metropolitan area is significantly confined by flood control infrastructure, but some of the infrastructure and a number of bridges crossing the river were constructed before current standards were adopted and may not be able to withstand the significant flows that may occur. There are unprotected portions of the Santa Cruz River that pose significant hazards to nearby properties. This watershed contains 7,808 acres of SFHA, 10,878 acres of locally identified floodplain and 24,981 acres of Pima County Regulated Riparian Habitat.

Flood Hazards

Maps

Click HERE to view the watershed map
Click HERE to view the outreach brochure

Floodplain Studies

Floodplain Study FP-002-2017 - Ruthrauff Basin Management Plan Technical Data Notebook, JE Fuller Hydrology & Geomorphology Inc., 11/2/2015.

Floodplain Study FP-035-1999 - Earp Wash, DJA Engineering Corp., 3/4/1999.

Floodplain Study FP-040-2000 - Mission Wash Study for FEMA, McGovern, MacVittie, Lodge & Associates, 7/24/2000.

Floodplain Study FP-090-2014 - Airport Wash (South) Basin Management Study, CMG Drainage Engineering and Kimley Horn, 10/17/2014.  This study includes several separate reports covering Hughes Wash, El Vado Wash, Santa Clara Wash and Valencia Wash.

Floodplain Study FP-093-2016 - Airport Wash Basin Management Study, CMG Drainage Engineering and Kimley Horn, 06/25/2016.

Erosion Studies

There are currently no erosion studies in this watershed.

Areas of Interest (Known Issues, Gaps, Problems and Needs)

Issues Provided by Public and Stakeholder Input

No issues have been identified to date.

Issues from the District Flood Response Manual

8.14.1 Data Gathering Needs
• No site specific issues identified.

8.14.2 Frequently Flooded Structures and Properties Subject to Damage
• The Casas Arroyo subdivision is located on the outside of a bend in the Santa Cruz River and may experience flooding and erosion problems. (T13S R12E Sec. 01)
• Tetakusim Road and Settler Avenue (T15S R13E Sec. 19)
• The homes in the vicinity of Oriole Circle and Mayes Place are some of the most frequently flooded structures in Pima County. Water in structures up to 18 inches deep due to Valencia Wash. (T15S R13E Sec. 09)
• Homes have been known to flood south of Irvington Rd. and east of San Joaquin Ave. (T15S R13E Sec. 04)
• Wyoming Wash in the vicinity of Irvington Rd. and La Cholla Blvd. flows approximately 300 feet wide (across Sindle Pl, to the north) T15S R13E Sec. 03)

8.14.3 Infrastructure
• The Ina Road bridge gets shut down when flow is approximately 4-5 feet, equivalent to roughly the 25 year event, approximately 20,000 cfs. This issue is in the Town of Marana. (T13S R12E Sec. 01)
• The storm grate on the west side of Westover Ave. between Drexel Rd. and Canada St. has been subject to getting plugged up and causing flooding on nearby properties. A 2006 fix should improve the grate, but it’s worth following up on. (T15S R13E Sec. 04)
• The channel of the Santa Cruz West Branch is largely earthen and is heavily eroded in certain areas, such as where Dakota Wash enters the West Branch east of Mission Rd. and south of Irvington Rd. (T15S R13E Sec. 03)
• The floodwall for Mission West II subdivision is on private, individual lots and may not be properly maintained. (T15S R13E Sec. 20)
• The earthen embankment near the NW corner of San Xavier Estates is overtopped during the base flood. (T15S R13E Sec. 20)
• Santa Cruz River: 6700 N Silverbell Road (214-03-0400) is subject to channel bank migration. Based on the Sunset Road Bridge Study it is suspected that the bulk of the vegetation will be removed at 21,800 cfs. That vegetation is at the toe of the cut-slope and at a gentle outside meander. The home at 6700 N Silverbell Road is less than 100 feet from what will be a 30 foot cut-slope. (T13S R12E Sec. 01)
• Santa Cruz River: 6730 N Silver Ridge Road (214-03-0430) is subject to channel bank migration. Based on the Sunset Road Bridge Study it is suspected that the bulk of the vegetation will be removed at 21,800 cfs. That vegetation is at the toe of the cut-slope and at a gentle outside meander. The home at 6730 N Silver Ridge Road is less than 150 feet from what will be a 30 foot cut-slope. (T13S R12E Sec. 01)

8.14.4 Safety Concerns
• No site specific issues identified.

 

Recommendation of Actions and Floodplain Management Strategy

This section to be completed based on feedback received through the planning process.