How Walmart Solves Stormwater Management Challenges

Even Walmart Supercenters face water management challenges.

A Storm Water Solutions case study details how a well-engineered stormwater management system allowed a Walmart Supercenter in Santa Fe, New Mexico, to maximize water storage and minimize the project footprint. This allowed for additional parking and reduced the overall cost.

Walmart hired SMC Consulting Engineers P.C. to engineer about 17 acres of watershed, including the building, parking areas, driveways and landscaping.

Building a Supercenter on the previously undeveloped site would increase the impervious area of the site and thus increase runoff volume and rate of flow.

The development didn’t have space for an above-ground stormwater management system so engineers had to develop an underground system.

Additionally, Santa Fe faces sever drought conditions so collecting the runoff water to use for irrigation purposes was a top priority. This would allow Walmart to reduce its potable water use and comply with water rationing restrictions.

After reviewing various underground storage systems, engineers chose a modular precast concrete DoubleTrap system, manufactured by StormTrap LLC. The company provided one DoubleTrap system for storm water detention and a second system for rainwater harvesting. Both were tested extensively before commissioning.

The rainwater harvesting system is composed of 50, 10-feet DoubleTrap pieces and holds more than 15,000 cubic feet of storm water runoff collected from the roof catchment area. The stored water is later used for irrigation.

In addition to maximizing storage and reducing cost, SMC Consulting Engineers found that both systems were easy to install and all walk-through access for future inspection and maintenance, the case study says.

Meanwhile, General Motors says its new stormwater capture project at the GM Detroit-Hamtramck Assembly will save the plant nearly $2 million annually.

It will also save water: the plant will reuse captured rainwater for manufacturing processes throughout the 4-million-square-foot facility.