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GIS For Local Government Conference 2004 Presentation

Friday 28 October 2004: Session Tract 2

Denver Wastewater Uses DigitalGlobe Impervious Surface Map Products to Improve Efficiency for Storm Water Billing Purposes

Presentation Abstract

To help maximize the efficiency of its storm water billing operation, Denver’s Wastewater Management Division (WDM) initiated a pilot project in May 2003 to determine the effectiveness of using high-resolution multispectral (blue, green, red, near infrared) satellite imagery for mapping impervious surfaces in five Denver neighborhoods, including three residential, one commercial, and one industrial neighborhood. Denver’s WMD’s customer service group is responsible for billing all property owners in the City and County of Denver for sanitary sewer use and storm water drainage collection. Storm water runoff is a major contributor of pollution to reservoirs, lakes, streams and other surface waters. The storm water drainage bill is calculated by mapping the impervious areas – or surfaces that water does not penetrate, such as concrete and asphalt – contained within a parcel. Once the amount of impervious area contained within a parcel is determined, that property’s billing rate is calculated. While many cities that bill for storm water management do so by charging property owners based on average parcel size and landuse, Denver’s WMD bills property owners based on actual property size and total impervious surface area contained within the property. Essentially, property owners are billed according to their contribution to storm water runoff. WMD found that the QuickBird satellite imagery offers significant benefits in terms of cost and delivery time, allowing for quicker mapping, assessment, billing, and revenue generation at a lower cost to WMD.

Speaker Biographical Information

Jeff Liedtke, Director of Commercial Applications: DigitalGlobe

Jeff has been involved in the geo-technologies for over 15 years. With a background in remote sensing and digital photogrammetry, he has focused on extracting information from imagery to address real-world applications. Providing appropriate products and information to make well-informed land, resource and asset management decisions continues to be his quest.