Conservation of the Tortolita Alluvial Fan landscape has been promoted by Pima County and Town of Marana over the past two decades. An interdepartmental team was formed to evaluate flood and debris flow hazards and the potential to create an expanded Tortolita Fan Preserve. This report provides an overview of the alluvial fan characteristics and evaluates information on the significance of the biological and cultural resources to determine of the area meets the criteria to create a federal preserve.

The Augusta Resources Corporation proposes to construct the Rosemont Mine project in the northern Santa Rita Mountains. This report is a reconnaissance analysis of the conceptual flow and water balance in the area. The conceptual flow model for the area is based on topography, geology and precipitation and identifies the likely flow paths in the watershed and aquifer system. The water balance includes estimates of recharge to and groundwater flow from the area; there is no evapotranspiration discharge from the regional groundwater.

During the planning process for the SDCP, concerns were raised regarding loss of property tax revenue as well as adverse tax base impacts of Pima County purchasing parcels for open space. This report assesses impacts in two ways. First, the net assessed values of the open space parcels before purchase are compared to the sum of the net assessed values of all parcels in Pima County and in each applicable school district. Second, the property taxes assessed by Pima County and applicable school districts on each open space parcel before purchase is compared to the sum of the property taxes assessed on all parcels within Pima County and applicable school districts.

To facilitate development of the Environmental Impact Statement which must accompany the Section 10 multi-species conservation proposal, a series of issue papers have been written. This study presents a brief look at outdoor recreation issues and describes the impacts of five alternative permit strategies might have on the County's ability to maintain recreation opportunities.

Survey results for wetland plant communities of the Agua Caliente Park and nearby La Cebadilla property. The study also documented the presence or absence of Huachuca water umbel, a plant listed as endangered in Pima County. By studying the wetland plants of the La Cebadilla property, and through historic herbarium collections, the biologist found that several plants still present at La Cebadilla were known to be present at the Agua Caliente Ranch at the turn of the century.

This study from the citizens of the Arivaca community proposes to establish an Arivaca Resource Management Zone, where a atwo level management plan integrates the otherwise fragmented land use and water policies of the various regulatory agencies. The Arivaca watershed contains one of the last remaining cienegas and perennial streams in southern Arizona. These unusual water features exist because the area is still in a state of balance, where annual water consumption is less than the natural recharge replenishing the aquifer during years of average precipitation.

Elements of the comprehensive plan now include planning for water resources that must address the currently available surface water, groundwater, and effluent supplies and provide an analysis of how the future growth projected in the county plan will be adequately served by the legally and physically available water supply. This is the first study to be issued as part of the Water Resources Element and identifies a number of measures that can be taken to conserve water, including measures that can be taken by Pima County in the form of ordinance adoption.

In the early 1990s, a study of the Tanque Verde Creek by Dr. Julie Stromberg and others described the relationship between the depth to groundwater and the health of the mesquite woodland habitat in the area. This report revisits the Stromberg study to describe variations in groundwater levels since the report was completed early last decade. They identified around 3,000 acres of riparian vegetation in the Tanque Verde-Agua Caliente shallow groundwater zone.

Builds upon the "Biological Stress Assessment" through the identification of threats and stressors to watercourses within Pima County. It provides background on technical and water policy matters, describes potential and existing impacts to watercourses within Pima County, suggests options for reducing stressors, and outlines a number of issues for discussion withing each watershed planning unit.