Pima County Department of Transportation

Geographic Information Services Division

2004 Public Works Small Project of the Year Award Winner

The Pima County DOT GIS Division won the 2004 Public Works Small Project of the Year from the American Public Works Association, Arizona Chapter, for it's Pima County Sewer Conveyance Model.

The Arizona Chapter of the APWA awards program recognizes public works projects of outstanding merit.

Project Abstract

Pima County is experiencing explosive growth. An additional 15,000 and 20,000 people make their homes here each year. As new houses are constructed, additional wastewater is added to the existing sanitary sewer system. To plan for future demand, Geographic Information Systems (GIS) technology is being used to estimate when existing pipelines will reach their designed capacity. Using population projections extending into the year 2030, a GIS model was developed where the capacity of individual sewer interceptor pipelines can be evaluated and determine the year when they will no longer be able to carry the sewage flow from various basins within the service area. At this point, new sewage treatment plants will be required, pipeline capacity increased to accept additional volume or sewage rerouted to different treatment areas. Planners will have advanced warning and can prepare alternatives without interruption of service to homes and businesses, allocating scarce funding to where it will be needed most.