Tremé Recreation Community Center Project
Many Hands Make Light Work – Green Infrastructure Retrofit for NOLA Non-Profit
Since 2008, the Water Environment Federation (WEF) has organized an annual Community Service Project to help improve the water quality and environment of the city hosting WEFTEC. The project offers attendees and local design professionals an opportunity to give back to the host city while further developing their own expertise. In 2016, Construction EcoServices participated in it’s first event with WEF by helping construct a bioswale next to New Orleans City Hall. The project was a huge success and the bioswale is thriving in the urban environment. The native plants and trees look better than ever thanks to the volunteers from the New Orleans Water Collaborative that help with on-going maintenance. When WEF hosted their annual conference in New Orleans this year, Construction EcoServices was eager to be a part of their 11th annual event.
This year’s project brought a huge number of volunteers to the historic Tremé neighborhood. Danielle Duhe, from Dana Brown & Associates, used sustainable stormwater design practices to transform an existing 1,300 square foot planter box. The design intent of the project was to create a stormwater planter that would manage rooftop runoff while simultaneously educating the community and beautifying the iconic Tremé neighborhood. The existing drainage at the site daylights the downspouts above the raised planter, allowing water to sheet flow across grass and into City’s drainage via a catch basin in the street. In accordance with New Orleans’ Comprehensive Zoning Ordinance, the design team offered a solution to address detention and water quality. The solution consisted of removing the existing soil of the planter box, replacing it with bioretention media and installing a modular sub-surface storage underdrain. The bioretention media provides plants with nutrients to establish a healthy community, but also allows water to infiltrate into the underdrain below. The higher infiltration rate and larger void space allows stormwater to be managed within planter, rather than the existing clay soil that increase surface runoff volume. Overall, the design adds more than 1,000 cubic feet of storage and increases the amount of stormwater pollutants captured, while also serving as a public display to educate the surrounding community.
To prepare for the project, the New Orleans Sewerage & Water Board spent two days excavating and hauling off the existing soil, leaving an empty planter box. Originally, the design intent was to facilitate infiltration into the native soils. So, it was a surprise that after excavation was completed the construction team discovered a solid concrete. That didn’t prevent the project from continuing, instead the design layout was altered to accommodate the water that would have infiltrated into the soils below. The R-Tanks that were located in the center of the stormwater planter, were shifted to the planter box wall to help convey water into the existing weep holes. Since infiltration wasn’t an option, there needed to be a path for the water to leave the planter during heavy storms. One thing that all older cities have in common is that you never know what lies beneath the earth, until you dig it up.
On September 29th, over 200 volunteers arrived to begin work. The first step was to assemble 51 R-Tanks, while the remaining volunteers installed informational signage. The volunteers placed R-Tanks along the outer wall, then connected them to weep holes with drainage pipe. A layer of geotextile fabric was placed on the tops and sides of the R-Tanks, which prevents bioretention soil from migrating out of the planter box. Volunteers then installed two maintenance/inspection ports on the ends of the stormwater planter. After the sub-surface underdrain was backfilled with bioretention media by the volunteers, over 2,500 CF of the remaining media was added with the help of Twin Shores Landscape & Construction. Many hands make light work, but sometimes it’s nice to let the equipment do the heavy lifting. After the soil was raked and leveled, native plants and mulch were added. In order to prevent the downspouts from eroding away the bioretention soil, a layer of geotextile fabric and rip-rap were placed beneath each one.
Within one afternoon, a newly created stormwater planter took shape thanks to all the hard work of WEF, Dana Brown & Associates, Construction EcoServices, Twin Shores Landscape & Construction and the wonderful volunteers. These types of projects demonstrate how simple urban retrofits can be accomplished through collaboration and hard work. The result proves that Green Infrastructure can further improve our aging urban stormwater infrastructure through small additions. A lot of attention is given to large-scale projects that are going on around the nation, but local communities can make a significant impact on our environment.