The spread of invasive species creates serious environmental problems as well as economic hazards for residents and will hamper implementation of parts of the SDCP.

To facilitate development of the Environmental Impact Statement which must accompany the Section 10 multi-species conservation proposal, a series of issue papers is being published. This study discusses water resources in the context of the alternatives being considered to date.

Pima County assembled a comprehensive land cover map for the the SDCP and in the process of doing so, identified the strengths and weaknesses of prior mapping efforts. In order to combine the best aspects of past efforts, a common language had to be established among the classification systems.

An assessment of the problems that are presented by non-native and introduced species in maintaining native species and natural systems. Divided into two major sections, the study covers representative ecosystems in Pima County as well as representative species that have a negative impact on native species.

A companion to the study issued on July 5, 2000 entitled 'Cactus Ferruginous Pygmy-Owl Investigations in Pima County.' The major objective was to determine whether pygmy-owls chose nest sites or perch trees with characteristics that differ from other available sites within a nesting territory.

Brings together the findings of previous reports and suggests policies to address water quality issues in Pima County.

Compiles water quality data for the streams that have been identified as priorities and assesses land uses and potential pollution sources that might impact the water quality of the highest priority aquatic habitats.