Photo courtesy of Chesapeake Bay Program

Stormwater Management

What is Stormwater?

Stormwater is rainwater that falls on impervious surfaces such as rooftops, driveways, roads, sidewalks, and even lawns, which then flows off the site. As stormwater flows to our local streams, directly as sheet flow across the surface of the land or into storm drains, it picks up pollutants such as oil and grease from our roadways and driveways, nutrients from our lawn fertilizers, discarded litter, and bacteria from pet waste and other animal excrement.

Learn more about stormwater, the different ways to manage it, and how our team collaborated with a local community to help solve their stormwater problems.

Why is it Important to Address Stormwater?

Once in the stream, the polluted stormwater adds to the fast-moving surges of water associated with storms. This process causes erosion and destroys habitat for fish and other wildlife. By capturing and infiltrating stormwater on your property, you can help decrease the harmful stormwater and sewage overflows that run into waterways, improving your city, watershed, and the Chesapeake Bay.

Common Residential Stormwater Practices

Stormwater practices on individual residential properties are instrumental in achieving water quality goals in communities. They are important to connect the public to their local streams and the Chesapeake Bay, demonstrating that anyone can make a difference.

There are many reasons for installing a stormwater practice on an individual residential lot, from volunteer to mandatory stormwater management.

One of the main reasons is to address a stormwater concern on the property. A property owner may observe water issues such as water pooling in certain areas, consistently soggy or muddy areas, difficulty growing vegetation in an area, and evidence of erosion due to stormwater flow. Choosing to install one or more stormwater practices can help to resolve these issues. There may be incentive programs in your area to help. Your local soil & water conservation district or local environmental services may be able to direct you to available resources.

In many instances, regulatory requirements for new construction require stormwater practices to treat stormwater following land development. There has recently been a shift towards treating stormwater locally, on individual properties, instead of consolidating stormwater into a massive stormwater management pond. Developers typically install these required stormwater practices during construction, and property owners inherit these practices with little to no instruction on how to care for them. The resources contained here can help!

A rain garden is a bowl-shaped garden designed to capture and infiltrate stormwater runoff. They are designed to receive water from natural rainfall, downspouts and/or rain barrel overflow and sheet flow from surrounding areas. Garden size should be approximately 10% of the roof area directed to the garden and filled with perennial native plants.

Learn more about how to maintain rain gardens by visiting the Stormwater Maintenance Resource Center.


Is a Rain Garden Right for Your Yard?

Photo credit: Alliance for the Chesapeake Bay

A bayscape, or conservation landscape, is a garden filled with deep-rooted native plants. They are used to replace turf or exposed soil on gradual slopes and help collect sheetflow. Bayscapes help stabilizes slopes, reduce erosion, absorbs stormwater runoff, and provides pollinator habitats.

Learn more about how to maintain conservation landscaping practices by visiting the Stormwater Maintenance Resource Center.

Photo credit: RiverSmart Homes

Rain barrels are containers used to collect a portion of the rainwater that flows from your rooftop and stores it for uses such as watering your lawn and garden. By capturing water from downspouts that would otherwise discharge onto a paved surface, rain barrels can reduce the amount of polluted stormwater runoff reaching local streams.

Learn more about how to maintain rain barrels by visiting the Stormwater Maintenance Resource Center.

A cistern (essentially a larger version of a rain barrel) is a sealed tank used to collect and temporarily store rainwater that flows from the rooftop. Collected water can be reused for non-potable purposes such as watering your flower garden, trees, or lawn.

Learn more about how to maintain cisterns by visiting the Stormwater Maintenance Resource Center.

Photo credit: Prince George’s County DoE

The canopy of a tree or group of trees is the area of leaves and branches that create shade under the tree(s). Like umbrellas, trees reduce the amount of sunlight and rain reaching the ground. Trees in urban environments are particularly important for intercepting rainfall before it becomes stormwater runoff. Tree leaves, branches, stems, and roots catch falling rain, filter out pollutants, and absorb stormwater.

Learn more about how to maintain shade trees by visiting the Stormwater Maintenance Resource Center.

Permeable pavers can be used to replace conventional asphalt; such as driveways, walkways, patios and parking areas. When rainwater falls on conventional pavement, it accumulates and causes localized flooding and erosion. Permeable pavers allow stormwater to slowly infiltrate the pavers, replenish groundwater and improve water quality through natural filtration processes.

Learn more about how to maintain permeable pavers by visiting the Stormwater Maintenance Resource Center.

Photo credit: Chesapeake Bay Program

A green roof is a vegetated roof system that stores rainwater in a lightweight, engineered soil.

Learn more about how to maintain green roofs by visiting the Stormwater Maintenance Resource Center.

Photo credit: Chesapeake Bay Program


Synonyms: Indigenous, Drought Tolerant, Endemic, Natives, Beneficial Plants

Native plants of the Chesapeake Bay region are plants that have been here long before European settlement. They have adapted to local soils, climates, micro-organisms, and insects. Since they have evolved in natural conditions many native plants do not need excess care like fertilizers, extra watering, or other chemical applications like many non-native species need. Other wildlife relies on native plants to survive and reproduce, so planting native species will benefit birds, butterflies, and many other species.

Native plants are often superior to exotic plants in terms of stormwater management because they usually have deeper and more extensive root systems that prevent erosion and provide extra filtration. Since natives also require little to no fertilizer or chemical applicants, both of which can harm stream ecosystems, they are also superior for improving water quality.

Minimizing maintenance by choosing native plants will also save you time and money by cutting costs related to mowing, fertilizing, and watering your lawn or non-native plants.

Native plants are an intricate part of conservation landscaping. Native plants are superior choices from an ecological point of view when landscaping.

Search for native plants suited to your yard in the Native Plant Center; a searchable database of the native plants that meet your conditions.


Synonyms: Invasive, Exotic, Nonnative, Non-Native

An invasive plant is an exotic (from another part of the country or the world) species that has the ability to thrive and spread aggressively outside its natural range. An invasive species that colonizes a new area may grow more rapidly than native plants since the insects, diseases, and foraging animals that naturally keep its growth in check are not present.

Many invasive species are introduced through residential landscaping without a full understanding of how the exotic species will interact with the environment. Although some exotic species are more aesthetically interesting than their native counterparts, if they become invasive they can become real problems for local habitats. Invasive species are problematic because they can out-compete natives and significantly reduce biodiversity in ecosystems.

Decreasing biodiversity has a chain reaction of negative effects on other plant species, insects, and animals that are critical for thriving ecosystems.

Learn more about invasive species in the Chesapeake Bay by visiting the Chesapeake Bay Program’s Invasive Species Website.


Test your native plant knowledge by taking our “Plant This, Pull That” quiz!

Our Projects

The Alliance is committed to helping communities reduce the pollution that enters local waterways by installing practices that use natural processes to improve water quality.

Our partnerships and projects focus on community-based efforts that engage local landowners to implement this green infrastructure, which beautify urban environments, create pockets of beneficial habitat, and make for a healthier Chesapeake Bay watershed.