Green Infrastructure For Texas
Green Infrastructure For Texas

Mid-Scale Green Infrastructure

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Mid-Scale Stormwater Practices aim to treat a larger amount of an areas stormwater runoff (think neighborhood size) through a variety of practices that can incorporate both Green and Grey Infrastructure.

First, runoff can be diverted through pipes or concrete channels – Grey, open vegetated swales – Green, or overland flow into basins which can be dry basins, wet basins, retrofitted basins (to include floating wetlands) or stormwater wetlands. Each practice has different potential benefits and cost but all of them provide some increased level of stormwater control and treatment.

Which you choose depends on the location and type of soil you have and your desired benefits.

 

Stormwater Wetlands


Mason Park on Brays Bayou – Houston, TX
  • A constructed wetland with the expressed purpose of stormwater treatment. Such wetlands use hydrophytic plants (aka hydrophytes) and a complex of soil surface biofilm (algae and microbes) to reduce flooding and improve water quality in a specific watershed.
  • These systems are designed to treat at least a 90th percentile storm. Which on the upper Texas Gulf Coast is equal to 2-3 inch rain event.
  • Stormwater wetlands are not natural occurring wetlands and are generally not part of any required mitigation for loss of natural wetlands.

 

Benefits & Services

Flood Control the stormwater wetlands slow the flow of the water and hold the water for 72 hours as it slowly releases it back into the channel through the outflow structure. This slowing the water down allows for infiltration and evaporation of water so less water is released downstream.

Outflow structure at
Exploration Green, Phase 3A

Water Quality Improvements the plants also take up excess nutrients from the water and use them; while the biofilm break down harmful bacteria and oils at the soil surface.

 

Water sampling setup at Exploration Green

 

Wildlife Habitat Benefits
Stormwater wetlands create new habitat for migrating water fowl, resident bird populations, fish, insects and other wildlife. The flowers also provide food for pollinator species. While a healthy wetland system can even control nuisance population such as mosquitos using natural predators.

 

 

Education Benefits

Stormwater wetland creation in neighborhoods and park settings allow for community and school group field trips to learn about these systems and how they work. They also provide service learning projects through volunteer opportunities.

A group of students and community stakeholders learning about the engineering of the outfall structure from Dr. Jaber

 

Improved Recreation and Health Benefits

Bird watchers at a wetland
Recreation includes bird watching, nature photography and other eco-tourism activities in these community areas.
Studies show being out in nature can improve our overall health by reducing stress. Many of these stormwater wetland sites also include walking trails.

 

Existing Basin Design Elements

New Basin Design Elements
 

»  Hydrology
»  Site Selection
»  Size of Wetland
»  Appropriate Features
»  Outlet Structure
»  Vegetation Selection

 

 

 
»  Hydrology
»  Site Selection
»  Size of Wetland
»  Appropriate Features
»  Outlet Structure
»  Vegetation Selection

Maintenance

Nurseries and Plant List

Cost/Value Estimates

 

Floating Wetland (Retrofitted Wet Basin)

Photo courtesy of Pete Romfh taken at Pearland Nature Center
Another midscale practice is conservation design community development. We will briefly discuss some of the goals and benefits of this practice. However, we currently do not know of any neighborhoods in Texas that are using this method to show case here.