Cooperation Agreement No. CA 8000 -2 -9001
Work Order No. 8039 -2 -9001 / Within Saguaro National Park only Rincon Mountain District contains significant
riparian areas. The geologic framework of the Tanque Verde Ridge and Rincon Valley
exerts strong control on the hydrology of these riparian systems. Pantano fault
constitutes a line of hydrogeologic separation between the occurrence and utilization of
groundwater in the Rincon Valley and the main Tucson basin. No known, comparable
fault isolates the upper Tanque Verde Creek alluvium from downstream pumping effects.
However, east of the confluence with Agua Caliente Wash, the highly permeable alluvial
materials are much thinner, and serve to dampen such downstream effects. Therefore, the
ground water reservoirs supporting the riparian areas within Rincon Mountain District are
not directly connected to the Tucson basin aquifer.
In what is described herein as upper basin areas, high gradient tributary streams to
Tanque Verde Creek and Rincon Creek have discontinuous bodies of shallow alluvium
interspersed with bedrock channel. Alluvium has accumulated behind small faults or
resistant bedrock ledges and contains shallow ground water basins that support small
pockets of riparian or xeroriparian vegetation. The ground water in these small basins is
sustained by seeps or springs, and by runoff from precipitation and is not likely to be
connected to a regional ground water system.
In what we have characterized as middle basin areas, the stream gradients are less
than 25m/km. In these low gradient reaches, the alluvial floodplain sediments are
continuous, though not thick, as ledges of more resistant bedrock formations appear in
the stream channel. These low gradient reaches contain larger volumes of ground water
than the high gradient basins and support more robust riparian vegetation. The ground
water in the low gradient reaches is believed to be connected to the regional ground water
system. Such a low gradient reach exists in a tributary to Tanque Verde Creek about 1.4
km east of Wentworth Road and extends about 1.6 km into the Park. A similar low
gradient reach occurs along Rincon Creek in the Expansion Area, and at the mouths of
Chiminea and Madrona Creeks.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/615752 |
| Date | January 2001 |
| Creators | Baird, Kathryn J., Mac Nish, Robert, Guertin, D. Philip |
| Contributors | Department of Hydrology & Water Resources, The University of Arizona |
| Publisher | Department of Hydrology and Water Resources, University of Arizona (Tucson, AZ) |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Technical Report |
| Source | Provided by the Department of Hydrology and Water Resources. |
| Rights | Copyright © Arizona Board of Regents |
| Relation | Technical Reports on Hydrology and Water Resources, No. 01-010 |
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