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Cienega Creek Projects

Cienega Creek, located 20 miles southeast of Tucson, contains remnants of a historically extensive cienega system, defined by springs and marsh areas. Designated as an “Outstanding Water” by the State of Arizona, Cienega Creek contains critical habitat for many wildlife and plant species, including threatened and endangered species.
Since 1989, PAG has conducted monthly and quarterly hydrologic monitoring and research in Cienega Creek and Davidson Canyon in coordination with the Pima County Regional Flood Control District and Pima County Natural Resources Parks and Recreation.
PAG’s hydrologic monitoring includes:
  • Calculating the quantity of streamflow
  • Sampling the water quality to serve baseline data, should the creek become impacted by mining or development
  • Conducting repeat photography
  • Assessing the depths to groundwater at wells located throughout the preserve
  • Measuring and mapping the lengths of the intermittent, ephemeral and flowing segments of the creek
  • Monitoring erosion
  • Evaluating the impact of drought

Drought impacts can be seen in the variation of flow extent measured during PAG’s wet/dry monitoring.

PAG publishes reports detailing the results of hydrologic studies.
  • Click here to view the Cienega Creek Hydrologic Research and Findings for summaries of the latest findings and links to highlighted reports.

Take a 3D look at Marsh Station, to get a feeling for Cienega Creek’s lush perennial flow.

Mining Issues
Cienega Creek and Davidson Canyon are downstream from various mining interests, including the potential Rosemont Copper Mine in the Santa Rita Mountains and other limestone and gravel mineral leases along the creek.

Cienega Creek Watershed Map
The map below shows a birds-eye view from above Cienega Creek looking across the greater Santa Cruz Watershed. The location of the proposed Rosemont Valley open pit copper mine is shown where it could be located within the Cienega watershed, if approved by state and federal agencies. The map also includes symbology for locations of Arizona Outstanding Waters, perennial flows, the Tucson Active Management Area, etc.


Water Level and Water Consumption Studies in the Cienega Watershed

In 2012, PAG completed a report on groundwater use near shallow groundwater areas in eastern Pima County. The report includes totals of the number of exempt and non-exempt wells, drilling histories and water production estimates.  We found that a one mile buffer around the Cienega-Davidson shallow groundwater system contains 29 non-exempt wells and 355 exempt (private low-water use) wells.  PAG defined this system to contain upper and lower Cienega Creek, Davidson Canyon, Barrel Canyon, Gardner Canyon, and Agua Verde-Posta Quemada.  Each area has unique well histories and groundwater level trends. Overall, the total number of exempt wells drilled in the buffered areas has steadily increased since 1990.  PAG, in coordination with Pima County, has monitored groundwater and surface water in the Cienega Creek Natural Preserve (lower Cienega Creek) since 1989, thereby providing over three decades of water resource information.  As a result, the quantity and quality of water resource data for lower Cienega Creek is dramatically better than that available for many other parts of the Cienega Valley. Riparian habitat and well owners, alike, rely on shallow groundwater resources.

Pima County conducted a 2013 analysis of long term water level trends by Pima County using PAG data among additional sources.  This report shows a decline of most water-related parameters monitored in the Preserve.   From 1993-2011, precipitation showed a declining trend in the winter, but no trend in the summer.  During the same period, streamflow declined by approximately 50% with the most significant decline during June, which is a critical period for aquatic plants and animals each year.  The extent of surface flow declined from a high of 9.5 miles (1984-1996), to a low of 1.24 miles in June of 2012.  These trends cause researchers in the region to be concerned about the prospects for long term health of the aquatic and riparian system of Cienega Creek. 

Collaborative presentation from the Science in the Sonoita Plains Symposium in June 2013 regarding both of the above topics.


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