“SWMMing” Through Stormwater Management Challenges
Projects in watershed modeling, flow analysis, real-time control, inventory-keeping, and permit management
By David Engle
Urban stormwater ruins picnics and ballgames, raises floods, snarls traffic, threatens safety, wreaks destruction, costs cities millions in damage and disruption—and those are among the relatively short-lived effects. Stormwater runoff is also the leading source of water-quality problems nationwide, carrying sediment and other pollutants to lakes, streams, coastal estuaries, and even drinking supplies; one fairly recent persuasive report on this came from the United States National Research Council in 2008.
Austin: Flash-Flood Alley
“We do have a serious problem with flash flooding in urban areas,” says Susan Janek of the Austin, TX, Watershed Protection Department. “And we will do anything we can do that will give a warning or a forecast to the public and our first responders and give them additional time.”
Starting nearly a decade ago, the city began looking for stormwater modeling software that could be used for flood predictions. “We did an evaluation of our system in 2007, by a consultant who came in and evaluated our particular [team’s function], which is flood warning,” recalls Janek. “He had several suggestions for us to use in terms of predictive mapping and modeling and many different ways to go down that path.” One was the US Army Corps of Engineer’s suite of products—“which is excellent,” she says, “for regulatory floodplain maps.”
What-If? Decisions for L.A. and LA
Clark Barlow, a hydrologist and consulting engineer for software developer Aquaveo since 2005, assists stormwater managers in using that firm’s WMS (Water Modeling System) product at sites around the country.
At the time of this writing, Barlow was just wrapping up a project for Los Angeles (L.A.) County, CA, in which WMS was used to calculate stormwater runoff in two large, heavily developed drainage basins, the Dominguez Channel and Compton Creek watersheds, totaling about 115 square miles.
Redrawing Flood Plains
Los Angeles’ MODRAT watershed software also found its way into a proprietary version called xpwspg (for “Water Surface Pressure Gradient”). The XP prefix here signifies its developer XP Solutions (formerly XP Software). The company’s recent name change reflects an expansion of services in support of urban drainage and stormwater modeling.
Besides xpwspg, the firm’s software includes the flagship product xpswmm for hydrology and hydraulic modeling,
Anchorage: Designing Culverts, Thwarting Surcharge
Frank DesRoches is a licensed engineer for CRW Engineering in Anchorage, AK, and one of the firm’s leads for drainage work. CRW has been in business for about 30 years in Anchorage and in that time has done hundreds of projects involving stormwater drainage, he says.
|Photo: City of Austin
Lamar at 12th Street, September 2010
|Photo: Vieux and Associates
Screenshots of Vflo desktop software
In his design shop at CRW, DesRoches uses a number of software platforms, including Bentley CivilStorm, ESRI, and other GIS-enhanced products, as well as several nonproprietary modeling and design tools.
Edmonton, in Real-Time Control
More than a dozen years ago the city of Edmonton, AB, Canada, purchased software that combines hydraulic modeling with assessment and, ultimately, even enables integrated real-time control (RTC) of stormwater and sewerage. It also coordinates hundreds of digitized sensors as control components. Steven Chan of Edmonton’s Drainage Services office provides an overview.
Edmonton provides sewer services through three different systems: one for sanitary waste, a second for surface runoff, and a third combined sewer. All main trunks and some lateral sewers are included in the model. The sanitary and combined sewers end up at the same location, the Gold Bar Wastewater Treatment Plant (GBWWTP).
MS4 Permit Compliance
Do you need order, ease, and logic to help you meet the EPA’s rules for a stormwater management plan (SWMP) under the National Pollutant Discharge Elimination System (NPDES)?
A quick Web search will turn up wares of several vendors offering help. The following list is not exhaustive:
ASIST is a suite of interrelated desktop applications offering flexible tools for managing a municipal asset program, such as tracking citizen calls, work requests, traffic signs, signals, hydrants, backflow devices, and water lines to manage an NPDES program.
MS4 Permit Manager is a comprehensive SWMP database to assist NPDES Phase I and II MS4s in meeting centralized records and annual reporting requirements. Reports can be saved and opened directly into a standard word processing program for customization.
Two Web-based systems, PermiTrack and Stormpromax, help manage NPDES MS4 or construction permits and their requirements.
Maintenance in Margate
A final software category help cities to identify, track, and manage inspections of entire inventories of stormwater-related (and other) municipal assets.
One example is Atlas360, from Logic Concepts in Greenville, SC. Introduced only in 2010, Atlas aims at making it easy, as the company’s Bob Magee explains, to catalog “all inlets, outlets, catch basins, pipes, ditches,” and so on, along with “recording of their condition, for maintenance-tracking and other purposes, on GPS maps.”
Writer David Engle specializes in construction-related topics.
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