Green Marinas Part I – Beyond Stormwater BMPs

Waterfront business owners should recognize one thing: polluting natural resources pollutes revenue streams. Marinas sit at the intersection of recreation, industry and shoreline ecology, which means that stormwater management isn’t just an environmental issue. It’s a daily operational task.

Yet proper stormwater management isn’t always top of mind, and hiring the right professionals to do the work can feel both a time and budgetary constraint. The truth of the matter is, when done well, stormwater systems can satisfy both form and function by protecting waters from harmful pollutants and increasing the marketable value of marinas.

Stormwater BMP Basics
Stormwater Best Management Practices (BMPs) are the guiding principles set forth by the American Society of Civil Engineers (ASCE) Manual 50: Planning and Design Guidelines for Small Craft Harbors. These best practices have been established to protect natural resources such as lakes, rivers and oceans from contamination. The BMPs target pollutants called total suspended solids (TSS), which are undissolved particles larger than 2 microns in size, such as sand, gravel, silt, salt, runoff or man-made pollutants (gas, oils, chemicals, etc.).

TSS in large quantities are known to pose a threat to the health of our aquatic ecosystems by decreasing water’s natural dissolved oxygen levels and

increasing water temperature. TSS can also escalate the turbidity of water, blocking sunlight and stunting photosynthesis, not to mention turning the look and feel of a once-pristine water body into something far less desirable.

Common sources of TSS pollution at marinas and waterfront properties are impervious hardscapes, such as parking lots, buildings, roofs, roads and sidewalks. Parking lots are some of the worst culprits as they are collectors of all sorts of contaminants from vehicles, such as salt, mud, gas and oils. All these pollutants are funneled into the nearest lake or river, if left unaddressed. Fortunately, marinas have a variety of opportunities to incorporate impactful management systems to intercept these pollutants before they reach the water.

Collection and Treatment Options
A few key elements of stormwater management include sediment basins, constructed wetlands, rain gardens and forebays. Options vary in shape and size and can be excellent aesthetic enhancements to a marina.

Sediment basins are designed to capture and temporarily store stormwater runoff, slowing water flow and allowing time for sediment to settle before discharge.

Constructed wetlands are composed of a combination of wetland vegetation, soils and microbial properties that filter sediments and pollution to help improve water quality on its way to receiving lakes and rivers.

Rain gardens are relatively shallow depressions in the ground planted with native vegetation to capture and filter stormwater runoff. Rain gardens excel at preventing erosion by establishing deep roots that hold soil in place and are a cost-effective means to introduce perennial plants and attract birds while reducing runoff.

Forebays are small, engineered basins for collecting stormwater and a means to trap and filter sediment, debris and runoff before it enters a larger body of water. Forebays function very much like rain gardens: living, growing, wetland-like features with native plants whose deep roots absorb water and sediments, essentially “cleaning” contaminants through a combination of microbial action in the soil, vegetative uptake, evaporation and transpiration.

Benchmark Design
Effective stormwater management goes beyond installing the features mentioned above by turning functional features into amenities that elevate the marina experience.

Engineers, designers and stormwater professionals are compelled to make traditional BMPs the baseline, not the benchmark. While most DNRs do not require utilizing a professional stormwater engineer or design team to do the work, it is the most holistic strategy to protect the environment, boost business and deliver the most functional and aesthetically appropriate solution possible.

Aesthetically appropriate solutions should consider the context of a location. For example, a stormwater management system developed for a marina on the Great Lakes should incorporate elements designed to look like the edge of a coastal wetland, utilizing plants that would be native to that environment.

Stormwater design at marinas along riverfronts, by contrast, should replicate the riverine environment, with sediment bays or constructed wetlands showcasing species such as cattails, rushes and emergent plants and grasses that are adaptable to wet soils and assist with erosion control. The goal is to make the functional side of stormwater management seamlessly integrate into the surrounding environment.

This holistic design approach can be referred to as “green engineering” and can be guided by the expertise of a professional landscape architect. Landscape architects and engineers team up to assess both the hardscape and the softscape of a site and consider how they work together to create one cohesive user experience. In the case of stormwater management, these professionals can be instrumental in helping to neutralize the impacts of the built environment by creating green spaces, wetlands, restoration areas, pollinator habitats, sediment bays, forebays or rain gardens to thoughtfully disguise the operational performance of the stormwater infrastructure. The result is something of functional beauty, which is much more pleasing to the eye than a large overland pipe funneling stormwater through the heart of a marina community.

While there may be a greater up-front investment to hire a professional, and the process might take a bit more time, the long-term cost benefits and relatively quick return on investment are worthwhile. More importantly, proper stormwater design can be highly nuanced as well as very site-specific. The goal is to do the work once, and do it correctly, without adversely impacting the surroundings or the aesthetic of the marina or waterfront property.

The Value of Sound Design
The true value of a properly designed and engineered stormwater system is public perception. When things look good, they feel good. People will want to be patrons; they’ll want to keep their boats at the marina and show off the property to friends. Creating a clean, polished marina atmosphere attracts new customers and retains existing ones. A thoughtfully designed stormwater management system is a big part of that.

Stormwater systems offer great opportunities to enhance the entire marina ecosystem, design more resilient public spaces and improve site aesthetics. When thoughtfully designed, these systems transform regulatory obligations into features that elevate the customer experience and support the long-term health of the waterfront. Most importantly, they reflect a marina’s commitment to environmental stewardship, illustrating to boaters, visitors and the broader community that caring for the waters is at the heart of responsible marina ownership. By embracing this mindset, marinas not only protect their natural resources but also ensure the enjoyment of recreational waters and revenue sources for generations to come.

Dan Williams, PLA, ASLA, AHLP is principal landscape architect at MSA. He can be reached at dwilliams@msa-ps.com. Marcus Rue, PE is engineering team leader at MSA. He can be reached at mrue@msa-ps.com.