A bioretention is flexible by design with a plethora of opportunities for the designer to get creative. The stormwater best management practices (BMP) can be achieved in several different ways and located in many different greenscape areas on a property. Therefore, there is a process of planning to consider in the bioretention plant selection and design.
The Metropolitan Sewer District and the Missouri Department of Conservation have performance criteria’s and many requirements. MSD has a list of performance criteria for storage volume, filter bed (soil bed) area, and runoff volume reduction. The Missouri Botanical Garden also has a guide and list for the MSD requirements for the construction, soil, sand and gravel specification, pipe specification, plant selection, maintenance and inspections of these vegetation cells. The requirements depend on the objective of the cell and the location.
The CAD design will need to be completed by a Landscape Architect and submitted to MSD for approval with a life time maintenance plan in place. The firm will meet the criteria and the requirements for MSD and BMP for proxy to building, geotechnical evaluation and pre-construction soil testing, construction sediment control, pre-treatment, on-line, offline and overflow assessment as well as other concerns and processes for the project. The firm will choice the BMP design for your site. Whether it be a Bioretention, dry swale, wetland, sand filter or wet pond.
Plant requirements are a very important part of the BMP. Missouri and S. Illinois require ecotype plants with a recommended minimum of sedges and forbes to provide the BMP. State natives and the plants characteristics need to be known for BMP design and maintenance of the areas. Plants are selected for the required and recommended list for the best plant for the place – weather formal, informal, dry soils, wet soils, full sun, shaded area and filtration usage, etc. These areas will need to have an aesthetic appeal with the taller tree and shrubs in the center and the lower forbes on the outside and edges of the beds.
Once the bioretention areas have been installed and established a professional landscape maintenance company should be hired to maintenance and inspect the areas throughout the year. Knowing what is a native plant verse a weed is very important for these areas. Bioretention areas can quickly get out of control with invasive weeds if left unattended or weeds are not pulled that are mistaken for native plants. Also, if the pollution filtering native is pulled by mistake the bioretention areas is not able to work as designed.
Designed and maintained correctly, these areas can offer year round interest and be very colorful. They become a wildlife refuge with seed and berries for food and shelter. Any effort to slow down the first flush of stormwater runoff in the St. Louis water ways is a positive move forward!
Our certified stormwater best management practices inspection and maintenance professional manages and submits all of the needed inspections and annual reports to the Metropolitan St. Louis Sewer District for you. We can keep these areas working properly and help you achieve a greener way of doing business.
We can help you properly install and maintain your bioretention systems. Give us a call at 314-770-2828 or use our simple contact form to discuss your sustainability needs.