A number of significant positive and negative economic impacts could result from Pima County's SDCP and related programs, according to an analysis of existing research on large-scale conservation planning undertaken to provide a framework for community decision-making. This report offers no final verdict on the net economic impact of Pima County's current, ambitious initiatives in habitat conservation and growth management. However, it does provide a framework for future assessment and decision-making.

In February of 1998, the Pima County Board of Supervisors launched what has evolved into the Sonoran Desert Conservation Plan (SDCP) -- a comprehensive effort to protect the Sonoran Desert, guide growth and rationalize land development in the metropolitan Tucson region. Proponents of this planning process maintained that the project would reconcile conflicts between human activities and conservation, providing benefits for both wildlife and economic development. Critics, however, have increasingly alleged that implementing such an initiative will adversely affect land and housing markets, increase taxes and create problems of housing affordability. Over time a pressing need has consequently grown for objective information about the possible fiscal and economic impacts of the conservation programs being assembled by Pima County. This report addresses that need. It is a tool in the form of an impartial framework for assessment that government officials, environmentalists, business people and the general public can use for debate and decision-making.

A series of 51 individual “stakeholder” interviews and two focus groups conducted with members of the Pima County business community in fall, 2001, documented significantly divided opinion about the likely economic impacts of the county’s Sonoran Desert Conservation Plan (SDCP). The results of the stakeholder inquiries were striking. Only one major finding reflected consensus, while several others revealed sharp differences of opinion in the business community about the potential economic impacts of the SDCP and associated initiatives.

This report provides a simplified method to be used for evaluating the skin friction and tip resistance of axially loaded drilled shafts. A summary of literature and current practice was completed and then a comprehensive set of field and laboratory tests was performed. Several soil samples were collected from different sites from Arizona and surrounding states. Large scale direct shear apparatus was developed and used to determine the friction between soil and concrete. Finite element analyses were conducted on several prototype cases to determine effect of soil parameters such as dilation on the skin friction values. A step-by-step simplified approach was introduced to determine the skin and tip resistance of drilled shaft foundations in gravelly soils. An example application was presented to guide users in utilizing the simplified approach.