Tortolita Fan

To provide comments on this watershed for consideration in the Floodplain Management Plan, contact Greg Saxe
Planning Manager
(520) 724-4633.
The Tortolita Fan watershed includes the Cottonwood, Prospect, Cañada Agua and Hardy washes that drain the southwestern slopes of the Tortolita Mountains.  Originating from the Tortolita Mountains and continuing on the relatively gentle slopes of alluvial fans, these washes terminate in the geologic floodplain of the Santa Cruz River. Flood risk in this alluvial fan includes poorly defined washes with the potential for significant changes in flow direction due to flows breaking out of existing channels and continuing downhill via unpredictable new paths. Floods develop quickly and may carry a significant amount of sediment and debris, which may cause damage and further divert flows in unpredictable ways. Sheetflow flooding is the dominant type of flooding that affects residents of this area. While sheetflow flooding is generally fairly shallow, it is also very widespread and makes accessing properties difficult. This is especially true due to the prevalence of unmaintained dirt roads. In sheetflow floodplains, it is important to protect your home from flooding and obtain flood insurance, but it is not appropriate to prevent your property from flooding as this makes flooding worse for neighbors. This watershed is comprised of 38,838 acres and contains 10,130 acres of SFHA, 7,544 acres of locally identified floodplain and 6,824 acres of Pima County Regulated Riparian Habitat.
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Regional Flood Control District

201 N. Stone Avenue, 9th Fl.
Tucson, AZ 85701

Phone: (520) 724-4600
Fax: (520) 724-4621

Customer Service Hours:
8:00AM - 4:00PM

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