Shoreline property upgrade saved by Lightweight stormwater solution case study
Renovating a residential property may be commonplace, however upgrades adjacent to the sensitive Bayou Texar estuary in Pensacola, FL, is a bit more difficult. The estuary is an ecologically sensitive area protected by the Florida Department of Environmental Protection. The consulting engineer and contractor had a problem; with limited space, how do they keep stormwater on site with the addition of a new pool and covered garage. Traditional stone retention systems, pipe, and arched chambers could not be used. The solution turned out to be a lightweight, modular and stackable stormwater detention system.
The pool and covered garage are considered impermeable surfaces requiring the consulting engineer, James Baynes, Jr., of Land Consulting and Improvements, to come up with an innovative solution. The contractor would have no way to haul large amounts of stone to the back of the house where the stormwater retention needed to take place. The house backs the Bayou Texar and the upgrades made to the home made it impossible to get machinery around to the back. Hauling stone by hand would be too expensive and time consuming and hauling stone by boat would also be cost prohibitive. Corrugated plastic pipe and arched chamber systems also require a percentage of stone to help with storage capacity and structural support, so while investigated, they were eliminated as solutions.
That’s when contractor Brian Batte of Gulf Breeze Plumbing started shopping around. Batte wanted a lightweight system that could be carried manually around the house to the back. Batte also needed a highly efficient system since the excavation for the system had to be done by hand. Batte, with the help of Baynes, located Rainstore3 stormwater detention system manufactured by Invisible Structures, Inc. Rainstore3 weighs only 15 pounds per unit and each unit can store nearly 25 gallons of water. Each unit can be stacked, like Legos®, and each stack can be set adjacent to one another for a modular system. Baynes and Batte had each found their respective solutions; Baynes for the efficiency and function; Batte for the weight and installation convenience.
Land Consulting and Improvement and Baynes make it a practice to go above the local regulations for stormwater containment – meaning he designs his drainage plans to account for the total stormwater runoff, not just the new additions or upgrades. To protect the estuary from runoff, Baynes sized his foundation drains, strip drains, and Rainstore3 detention chambers for all the impermeable surface on site: The house, the new pool, the new garage, and the paved areas. The sizing led to 495 units of Rainstore3. At 94% effieciency, 495 units will hold 46.53 cubic meters (1643 cubic feet) of stormwater. Baynes’ plan ended up with 8 individual Rainstore3 chambers, varying from two stacks to 18 stacks, connected by drains and pipe, at different points on site. Each stack was 9 units high, .9 meters (2.95 ft) at 1 meter long by 1 meter wide (40 inches x 40 inches). The individual chambers are configured adjacent to the house, spa, pool, terrace, fireplace, fountain, shoreline retaining wall, and garage at different angles and sizes.
“Easy and user-friendly,” is how Baynes describes his experience with Rainstore3. “Overall… Positive.”
As of the publication of this article, Rainstore3 has been shipped, is on site, and is waiting for installation when the weather permits.