Green Infrastructure

BREC’s Commitment to Resiliency and Sustainable Stormwater Management

The great flood of 2016 was a wake-up call for East Baton Rouge Parish and our region. A number of BREC parks took on and held stormwater through their open space, or green infrastructure – especially our larger community parks like Greenwood, Howell, Airline Highway, Burbank Soccer Complex, and Central Sports Park, to name a few. Howell Park’s 60-year-old recreation center received between 6 to 7 feet of water and was basically destroyed. In the aftermath, BREC recognized how much stormwater our parks held – nearly 10 billion gallons in the 2016 flood – that’s enough to fill Tiger Stadium 71 times. All of this floodwater would have otherwise gone into the homes and businesses in the surrounding areas, creating even greater devastation.

BREC is committed to providing essential outdoor spaces for our Parish residents to live, play and interact with neighbors. The 6,600 acres of parks that BREC manages contributes to the conservation, health and wellness, and social equity of our local community. As an agency, we are committed to ensuring that BREC properties offer the maximum benefits possible to residents not just recreationally, but from an ecosystem services standpoint. Our parks have the capacity to naturally soak up and hold stormwater runoff, reduce flooding, reduce urban city temperatures, sequester carbon to clean our air, and much more. We can increase the capacity of our parks to provide these benefits through sustainable resilience planning and design. Incorporating green infrastructure elements into our parks protects these existing natural lands while providing valuable ecosystem services to the public as land use changes throughout the Parish.

What is Green Infrastructure?

Green infrastructure is an interconnected network of open green spaces and parks that conserves natural ecosystem values and functions and sustains clean air and water. Green infrastructure also includes a nature-based approach to stormwater management that protects, restores, or mimics the natural water cycle. There are many green infrastructure types and strategies such as bioswales, native plantings, green roofs, permeable pavement, rain gardens, and rain barrels. However, they are all designed with the common purpose to slow down, store and/or filter stormwater.

Illustrated diagram labeled with elements of green infrastructure

The idea behind green infrastructure is to mimic the way that our natural ecosystems such as wetlands, forests, and prairies naturally manage rainwater. There are typically 6 ways that our natural ecosystems do this including:

Educational illustration demonstrating stormwater management methods - rainfall pathways
  • Infiltration - The process by which water soaks into the soil
  • Storage - The ways in which water is held or locked up in its present state for a period of time. This includes short-term storage in rivers, creeks, bayous, ponds, lakes, and wetlands; or long-term storage on deep groundwater reservoirs or aquifers.
  • Evapotranspiration - Water that is released as a gas or vapor either through evaporation or via plant leaves through a process called transpiration.
  • Interception - The process by which rainfall is caught and held by leaves, branches, or other plant matter.
  • Runoff - Stormwater that lands on already saturated soil or ground material that is impermeable, shedding the stormwater overland to the lowest location.
  • Uptake – The process by which plant roots transport water and nutrients from the soil up into the plant. The amount a plant uptakes varies depending on the depth of the roots and size of the plant (trees range from 10-150 gallons daily).
Educational illustration demonstrating how bioswales filter water before entering storm drains - bioswal impact on gray infrastructure

A city’s gray infrastructure, such as drainage ditches, curbs, gutters, storm drains, pipes, culverts, canals, and mechanical pumping stations, are designed to direct and remove stormwater runoff from paved surfaces as quickly as possible. Alternatively, built green infrastructure can reduce the impact on gray infrastructure by incorporating designs that intercept runoff before it reaches paved surfaces while also filtering pollutants and sediments from the water in the process. Reducing impacts to gray infrastructure not only reduces flooding potential, but also reduces maintenance costs and construction costs of new gray infrastructure. There are many more benefits to green infrastructure which are described below.

Why is Green Infrastructure Important?

Green infrastructure has many uses and benefits to the community. We highlight a few of them below. The types of green infrastructure elements and the benefits they provide, far exceed this list.

Flood Abatement/Stormwater Management
Erosion Control
Increase Biodiversity

Types of Green Infrastructure in the BREC system

Bioswales Educational illustration diagramming the impacts of a  bioswale A bioswale is a type of bioretention that receives stormwater from a small area like a road or parking lot. Once water enters the bioswale from surrounding impermeable surfaces, it is slowed down, and filtered by planted vegetation. Bioswales are typically linear and are used along roads, sidewalks, and within parking lots.
Photo of bioswale

Parking lot bioretention with surface ponding well in foreground, Kortright Centre, Vaughan, ON
Photo Credit: https://wiki.sustainabletechnologies.ca/wiki/Bioretention

Rain Gardens Photo of Urban Rain Garden

Extended tree pit planting in USA Photo credit: USEPA
Photo Credit:https://wiki.sustainabletechnologies.ca/wiki/Bioretention

Similar to bioswales, rain gardens are a type of bioretention that use native vegetation to slow and absorb water. They often do not contain any type of subdrain or soil amendments and strictly use native water-loving plants to contain and filter the stormwater. They normally contain an overflow drainage system and are not restricted by size or shape. Although rain gardens don’t need to have a large surface area they can often absorb runoff from buildings 5 to 10 times their footprint. Rain gardens may not look any different than a regular garden, except for the types of plants they contain and are usually more recessed into the ground to hold water.
Native Plantings

Five acres of native plant Grow Zones help manage stormwater at BREC’s Manchac Bayou Park

Photo of sign that reads Grow zone do not spray do not mow - large grasses and plants growing around sign Native plantings are a type of bioretention and erosion control that utilizes native plants in the landscape to slow and filter water and hold native soils in place. Similar to rain gardens, they do not require specific sub-grade or drainage parameters. Because only native plants are used, they are more sustainable than some other types of landscaping and require less fertilizer to survive due to their longer and thicker root networks.
Grow Zones are a type of native planting that mimics a native prairie and typically cover larger areas (1-10 acres). Grow zones are usually seeded as opposed to planted and have the added benefit of reducing mowing costs and emissions in BREC parks.
Permeable Pavement Education illustration of a segment of pavement showing convential pavement and permeable pavement side by side in rainy conditions Permeable pavements are similar to conventional pavement as they provide structural support for vehicle, bicycle, and pedestrian traffic but have the added benefit of allowing water to infiltrate through the pavement surface, and into an underlying aggregate reservoir. Permeable pavements can be made of open pore unit pavers with joints that allow water infiltration, or special mix designs of porous concrete or asphalt. They are designed to collect and store water that would normally be shed into a subsurface storm drainage system by an impermeable surface such as parking lot, road, or building. Permeable pavement reduces the load of stormwater in our conventional subsurface stormwater systems that outfall into our rivers and canals.
Permeable pavement can take on many different forms including: segmented image depicting 4 types of permeable pavement with labels - permeable asphalt, permeable concrete, permeable pavers, and platic or concrete grid system

Different kinds of permeable pavement
Photo Credit: United States Geological Survey

Green Roof

Succulent garden on top of the Baton Rouge Main Goodwood Library roof

Photo of green roof with plants growing up from gravel

Photo Credit: Tipton Associates

A green roof is a roof designed with a vegetative layer planted on top of a flat roof. The vegetation grows in a specially designed soil mix which sits on top of a drainage layer or membrane. Green roofs are designed to capture and soak up stormwater that would typically fall on a building, then travel through its gutter system which sheds the runoff from the roof rapidly. Instead, stormwater is captured for a short time, is filtered, and then either evaporates, or drains off the building after the rain event has passed at which time, the gray infrastructure can better handle the load. Diagram explaining green roof concept

Image Credit: National Park Service

Rain Barrels

Rain barrel collecting stormwater runoff from the pavilion at Bluebonnet Swamp Nature Center

Photo of rain barrel collecting water through pipe Rain barrels and cisterns are a form of rainwater harvesting that collects water from a surface, such as a roof, for re-use within a building, or for landscaping or gardening. By capturing stormwater in the barrel or cistern, it removes it from the surrounding impervious surfaces and gray infrastructure, ultimately reducing the impact to gray infrastructure. Rain barrels are typically 10-100 gallons and can be comprised of a single unit or be strung together to increase capacity. Within the BREC system, we use rain barrels at BREC’s Bluebonnet Swamp Nature Center to collect rainwater from the Swamp Pavilion and use it to pressure wash the pavilion deck and boardwalks.
Wetland/Ecosystem Restoration Photo realistic rendering of constructed wetland

Constructed Wetlands at Glenstone, Potomac, Maryland
Photo Credit: the American Society of Landscape Architects

Constructed wetlands are man-made wetlands designed to mimic the function of natural wetlands to capture stormwater, reduce nutrient loads, and create diverse wildlife habitats. According to the EPA, 1 acre of wetland can store 1 – 1.5 million gallons of floodwater. Sometimes this form of green infrastructure is used where historically wetlands occurred to re-establish the habitat or in locations where they would not occur naturally to aid in drainage or to help create a buffer or transition between ecosystems. Constructed wetlands can remain saturated year-round or may go through wet and dry cycles and a variety of native plants are chosen for specific performance measures. Constructed wetlands are planned in several future projects including BREC’s Greenwood Community Park Cypress Bayou Watershed Project, Howell Community Park, the new Airline Highway Community Park, and BREC’s City Park Lake, as part of the University Lakes Project. educational illustration of a constructed wetland diagramming how water flows through

To learn even more about what BREC is doing in the field of Green Infrastructure, visit the Green Infrastructure Planning page

What can you do?

We all have a role to play in creating a greener, more sustainable community in EBR Parish. Here are a few things that you can do to help:

  • Plant native plants in your backyard
  • Clean out your storm drain closest to your home
  • Educate yourself about stormwater management so you can recognize areas we can improve
  • Dispose of yard debris and waste properly so it does not clog storm drains
  • Support local organizations and businesses that promote the use of green infrastructure and sustainable building and design
  • Elect local officials that support the use of green infrastructure and resilience planning for EBR Parish
  • Volunteer with an organization like BREC to actively help plant, weed or maintain green infrastructure in the Parish
  • Educate others about stormwater management and the benefits of green infrastructure.
  • Opt to transition your yard from non-native turf grasses or concrete to native plants with deep roots. Bonus….you don’t have mow them!
References
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