Abstract:
This paper describes a partnership of the Bureau of
Land Management (BLM), the Bureau of Reclamation
(Reclamation), the University of Arizona, and the
Arizona Department of Water Resources (DWR). The
partnership is assessing and restoring the San Simon
watershed, a sub-basin in the Upper Gila River
Watershed. EPA selected that watershed as one of 12
Clean Water Action Plan Showcase Watersheds.
The San Simon River incised early in the 20th century.
Primary land uses within the San Simon Watershed
include recreation, a designated OHV use area,
farming, and livestock grazing. BLM installed grade
control structures on the San Simon River and
tributaries, beginning in the 1930s. The purpose of the
grade control was to halt channel incision and
degradation of the watershed land resources. In all,
there are 19 major detention dams, several dikes, and
earth structures. They all require assessment to
determine effectiveness and condition for
repair/maintenance. The Safford Field Office proposes
to complete an assessment of the San Simon River
watershed as a prerequisite to a community-based
planning effort setting the future direction and
management of the watershed.
The assessment will answer three questions:
1. Are the existing grade control structures
effective?
a) Are the structures hydraulically and
geomorphically effective?
b) Is maintenance of the existing structures
cost-effective?
2. Would additional grade control structures
hasten the restoration of the river and tributary
channels, and aid in the recovery of the
watershed?
3. How does the Resources Inventory and
Assessment of the uplands and the San Simon
channel depend upon the grade control
structures?
Reports and other documents about Sonoran Desert ecology, management, and conservation. Curated by the not-for-profit Altar Valley Conservation Alliance (AVCA) located outside Tucson, AZ.