Using GIS for Effective Stormwater Runoff Management

Recently, California experienced a series of storms that have brought large amounts of rain to urban areas. While this news is welcome in a state with recent years-long droughts, excess rainfall can overwhelm municipal wastewater treatment facilities and sewer systems. Effective stormwater runoff management is critical in avoiding dangerous flooding and spills of untreated water.

Reliable stormwater management practices are essential for many reasons. An effective stormwater management plan can prevent flooding and excess sewage draining directly into local water bodies during rainstorms that can swamp existing systems.

Thankfully, modern GIS data and monitoring technology can help utility operations managers effectively manage wastewater treatment facilities, catch basins, and drainage systems.

This technology also enables municipalities to plan communities and manage existing city infrastructure to avoid series flooding and runoff.

How GIS and Data is used to Manage Stormwater Runoff

Reliable GIS mapping and monitoring tools help collect data in real-time on such existing systems to monitor catch basins and existing stormwater flows, direction, and quantity.

This information helps cities and operations managers to take action before and during emergency flooding occurs and to avoid dangerous spills and polluted runoff.

Digitized maps of an existing facility’s infrastructure and stormwater drainage system enable field crews to quickly locate and inspect the condition and status of pipelines and catch basins. Armed with this data, they can conduct routine maintenance and take action during rainstorm periods.

Local governments and utilities can analyze data gathered via GIS technology and immediately identify problem areas. Using historical and current data, cities can develop capital improvement projects to improve wastewater treatment facilities and drainage systems.

The City of Mission Viejo uses Nobel Systems’ GeoViewer, a real-time and GIS-based utility management application, to monitor the city’s storm system layers. Joe Ames, the city’s assistant city engineer, says his department uses GeoViewer to view tributaries and catch basins. The city can see storm drain water flows throughout its entire system.

“The map we have allows us to see what areas we maintain and don’t; visually seeing if an area is maintained; then decide to refer issues,” Ames said.

Collecting Historical and New Data to Plan

Many municipalities in the United States have adopted stormwater management ordinances to monitor stormwater runoff, prevent spills, and contamination of natural and manmade water bodies.

Before a wastewater treatment facility or water utility can use a GIS system to gather data and monitor assets, they must have digitized maps of facility infrastructure.

Also, digitized models of the surrounding landscape and watershed are necessary to analyze where stormwater runoff is at a higher risk of overflow.

Developed land that contains roads, parking lots, and other impervious surfaces reduces the infiltration of water below ground and reduces groundwater storage and flow.

Because developed land cannot naturally absorb rainfall or water from snowmelt, the risk of stormwater runoff contributes to urban flooding, stream bank erosion and sedimentation, and polluted water bodies.

Collecting historical data from the surrounding landscape is the first step to effectively managing stormwater runoff.

This data can be used in master planning a community to decide where large scale projects such as schools, parking lots, and retail buildings are placed.

Spatial data on a city’s existing infrastructure and stormwater drainage system can help cities plan capital improvement projects to fix and maintain drainage systems. The data can also be used to design the restoration of natural habitats where it would benefit all.

In Summary

One of the many benefits of GIS for wastewater facilities and water utilities is to be able to manage existing assets effectively. Also, the technology helps municipalities plan for city-wide infrastructure that can handle future events such as stormwater overflow from rainstorms.

By implementing a sound digitized wastewater asset management plan, cities can help keep local water bodies safe and maintain high water quality for existing and future generations.