CRS Helps Grand Prairie Avoid Flood Damage
“We’ve always had flooding,” explains Stephanie Griffin, Floodplain Administrator for Grand Prairie, Texas, “but improvements over the last 20 to 30 years have helped tremendously in reducing flood losses in our city. And the Community Rating System was one of the major factors that encouraged this to happen.”
This community of about 183,000 people lies in the heavily urbanized metropolitan area between Dallas and Fort Worth. Johnson Creek, a tributary of the Trinity River, runs through the city’s 81 square-mile jurisdiction, creating a 13 mile stretch of floodprone area with a long history of flooding. Urbanization over the last several decades has brought localized street flooding into the mix, complicating the flood hazard. In all, about one-third of the community lies in the floodplain, including several hundred homes.
“We use a combination of floodplain management tools,” says Griffin. Open space work is dovetailed with stormwater management by keeping some city-owned property in recreational use, such as softball fields. “Because they have no buildings, these areas aren’t susceptible to damage from flooding and that minimizes community-wide damage,” she notes. What’s more, they serve as retention and detention basins during flooding, safely storing the water temporarily to alleviate overflows in other places.
Grand Prairie earns CRS credit points for the open spaces, the stormwater management, and the drainage system facilities.
Over time the city has made numerous improvements in the management of its system for conveying both floodwaters and stormwater and to its local regulations. Many of the city’s rules for the floodprone areas exceed the minimum requirements of the National Flood Insurance Program, qualifying for CRS credit.
According to Romin Khavari, P.E., CFM, City Engineer with over 31 years of experience with the City of Grand Prairie—and recipient of the 2012 CRS Award for Excellence—“the city continues to make improvements through current updating of the previous drainage master plans and identifying innovative approaches towards solving drainage challenges. Over a decade ago, Grand Prairie had 43 properties experiencing severe repetitive flood losses. As of April 2016, it is down to one!”
Grand Prairie has conducted hydrologic and hydraulic modelling for all of its watersheds. The model outputs show existing floodplain conditions as well as the projected conditions when the area is fully developed. Construction must be two feet above flood levels expected under existing conditions or one foot above those levels under future conditions, whichever is higher. The city-wide drainage master plans also include erosion zone setbacks.
Advanced Public Outreach
Grand Prairie is no stranger to active outreach programs. “But the CRS’s new Program for Public Information has caused us to step up our efforts in this area,” Griffin says.
The city formed a Program for Public Information Committee, engaging lenders, insurance agents, the public at large, school districts, and three city staff members. Under the Committee’s direction annual letters—in both English and Spanish—are sent to homeowners and renters in the floodplain, reminding them about flood insurance. A brochure on flood safety and flood insurance is also produced, and the city has a website presence for its floodplain management program. “I’d say that, because of the CRS and the PPI activity, we now have a vastly improved outreach program,” notes Griffin.
Along with other communities in the Dallas-Forth Worth area, Grand Prairie participates in a North Texas CRS Users Group that meets every other month to watch CRS webinars on various topics, discuss their common interests in floodplain management and the CRS program, and provide input and feedback on CRS-related activities.
Grand Prairie holds a Class 5 in the CRS, and is currently holding one of the best CRS ratings in Texas, earning a 25% reduction in flood insurance premiums for its residents. “Overall,” Griffin says, “the motivation provided by the CRS and its program activities have greatly reduced flooding in our community.”
“Through our proactive and innovative approaches to address drainage challenges, the current goal of the City of Grand Prairie is to enhance its efforts through the CRS and improve its CRS rating to a Class 4—all in service to our community and citizens” Khavari said.
Editor’s note: This is a just a glimpse of Grand Prairie’s floodplain management program. For more, see the city’s website.