Beginning in 2008, the National Pollutant discharge Elimination System permit required the identification, location and assessment of every stormwater structure that is owned, maintained or operated by the county. The majority of this work is limited to county-maintained roadways, but sometimes extends to drainage infrastructure owned or operated by homeowners’ associations and private entities. There are two major tasks involved in the project:
1. Global Positioning System (GPS) Field Data Collection
GPS crews locate and input data regarding all types of stormwater structures using the county’s Enterprise Collection System. Structure data is collected for drainage swales, ditches/channels, drop structures, storm drainage pipes, catch basins, weirs, control structures, ponds, and canals - including elevations and other dimensions.
2. Geographic Information System (GIS) Importation and Manipulation
Field data is imported into the county’s enterprise system, which includes a four-step quality control process, and is posted to a geographic database. An Infrastructure Inventory Location Map (PDF) shows that nearly 75 percent of known stormwater assets have been collected countywide.