A major problem, as in many waterways in urban areas, is trash. The Restoration team is responsible for the innovative trash trap installed at Nash Run. This is one way the AWS Restoration team is actively cleaning the river.  Most notably, we sort and measure the trash collected in order to plan for advocacy goals. The data collected at AWS trash traps has helped pass the bag fee law in DC and Montgomery County, MD (and measured its efficacy), the plastic straw bans in DC, Montgomery and Prince George’s counties, and the Styrofoam bans in DC, Montgomery, Prince George’s counties and the State of Maryland. 

The Nash Run Trash Trap project was started as a response to this problem with the support and funding of the District Department of the Environment. The goal is to capture trash before it enters the main tidal Anacostia. The trash trap was installed around the mouth of Nash Run, which is the entrance to Kenilworth Marsh. Via this marsh, the water and trash flow into the tidal Anacostia, making it a good location to proactively catch the trash.

In February 2009, our first trash trap was installed. Although extremely effective, there was clogging in the trap and some trash still got through the barrier. Our observation and experience of the trap over the next two years gave us the knowledge to improve the effectiveness of the design. The new trap is gently angled at 5 degrees to the ground. The stream force is used to push up trash, leaves, and branches on the screen to suppress the clogging. This allows stream water to flow through the trap as smoothly as possible. The modified and improved design was installed in June 2011. Since then, we have added one more trash trap at River Terrace, south of Nash Run.

Results

The first design captured approximately 3,300 lbs of “pure trash,” meaning bottles and cans are emptied and organic matter such as leaves was removed, between February 2009 through June 2011. Trash was sorted into 47 categories for the first 2 years and the data on weight, number of pieces were collected.  Then, the sorted trash was bagged into three major categories to allow AWS staff to study the trash characteristics by volume. Findings during the first 2 year study showed about 45% of trash was bottles and cans and 22% of trash was styrofoam. The detailed report is availabe online (https://doee.dc.gov/publication/demonstration-trash-reduction-technologies).  

AWS has been persistently and patiently continuing to collect the data.  The most recent volume analysis shows that only 1% is Styrofoam thanks to the Styrofoam bans in DC, Prince George’s Montgomery Counties and Maryland.  About 42% of trash remains bottles and cans.

The experience of managing 2 types of trash trap brought us great insight.  Nash Run Trash Trap is a screen type trap that captures both floatable and non-floatable trash.  River Terrace Trash Trap is a boom type trash trap that collects basically ONLY floatable trash.  It is obvious that the boom type trap does not capture non-floatable trash pieces.  Thus, AWS used Nash Run Trash Trap data to figure out how much non-floatable trash is escaping from the boom type trap.  AWS found that approximately 70% pieces of trash are not floatable.  This means that while the boom type trap, River Terrace Trash Trap, is very important to beautify the Anacostia River, approximately 70% pieces of non-floatable trash just flow through underneath the trap.

We also found that the maintenance of the screen type trap, Nash Run Trash Trap, is laborious and it is not practical to install screen type traps across the watershed.  Therefore, AWS uses the data from the traps to advocate for a better future: No one discards trash in our watershed and the environment.

Get Involved

It takes the support of many volunteers to help AWS maintain the trash trap. Look at our calendar of events to see when the next clean up of the Nash Run Trash Trap is for an opportunity to help clean the river alongside our AWS staff!

What are vernal pools?

Vernal pools are a unique type of wetland. Though often small and seasonal, they play a vital role in the ecosystem. These temporary wetlands typically form in late winter through early spring from snowmelt and rain, and usually dry up by mid to late summer. They provide essential breeding habitats for a variety of creatures that cannot reproduce in other areas.

Why are vernal pools important?

These pools are where wood frogs, spring peepers, spotted salamanders and other amphibians come to breed. Vernal pools are fish-free, so amphibian eggs and insect larvae are safe from these predators. Some species, like fairy shrimp or marbled salamanders, are found only in vernal pools. Vernal pools also help ecosystems and communities stay resilient by filtering water and absorbing floods.

What are threats to vernal pools?

Threats to vernal pools include:

• Climate change
• Trash, stormwater runoff, dumping, and other pollution
• Development, road salting, and other forms of habitat destruction

Vernal pools are declining rapidly because they do not meet current Maryland Department of the Environment wetland requirements or qualify for federal protections under the Clean Water Act as currently interpreted. This allows businesses to build on these wetlands without making up for the damage.

What does AWS do?

AWS has taken species inventories and mapped more than 40 pools since 2010. At eight of them we found species that depend on these pools to breed, including marbled salamanders and wood frogs.

We work with trained citizen scientists and master naturalists to monitor specific vernal pools and gather data to identify conservation and restoration needs.

AWS regularly advocates for protection of these rare ecosystems, testifying in the House of Delegates, signing petitions and informing the public of their importance.

What can you do?

Maintain natural vegetation and avoid applying pesticides, herbicides, or fertilizers near pools.
Participate in local vernal pool monitoring, restoration projects or citizen science efforts.
Stay on marked trails, respect vernal pool habitats, and educate others about their importance.
Educate yourself!

Earth Day Cleanup is on Saturday, April 25th!

About Earth Day

Started by DC native Howard Gasaway of Seafarers Yacht Club in 1985, the annual Anacostia River Earth Day Cleanup is AWS’s largest annual volunteer event and one of the largest single-day volunteer events in the DMV. This year, thousands of volunteers from around the watershed picked up trash, served our community, and enjoyed the Anacostia River. Read our 2025 Earth Day Cleanup After Action Report to see the amazing work accomplished by our volunteers, site leaders, sponsors, and government partners. 

We welcome all community members to be a part of one of the largest single-day volunteer events in the DMV. Please reach out to [email protected] with any questions.

Advocating for a Bottle Bill

Our Earth Day Cleanup is a part of our advocacy efforts towards a Bottle Bill in both Maryland and D.C. Bottle Bills incentivize aluminum, glass, and plastic recycling through a deposit and return system. Individuals receive a 10-15 cent return on the items they recycle. Currently less than 25% of bottles and cans actually end up being recycled, and end up in landfills, on the ground, or in our waterways. Our cleanup helps us collect data on how many bottles we are finding in the watershed to support advocating for a Bottle Bill. You can find more information on the Maryland Bottle Bill here, and the D.C. Bottle Bill here. 

City Nature Challenge – Pick Up the Trash to Uncover the Treasure!

The City Nature Challenge is an international community science event in which people can document all types of wildlife in their communities. This year, the CNC spans four days, from April 24 – April 27, and coincides with our Earth Day Cleanup. We are encouraging participants of the Cleanup on April 25th to, in addition to picking up trash, taking pictures of wildlife and plants to upload onto the INaturalist application. Participants have until May 10, 2026 to upload their photos. Pick up the trash to uncover the treasure!

In the spirit of sustainability, we collaborated with a local artist to design this year’s t-shirt to offer for sale through our Bonfire page rather than distribute them widely at cleanup sites. We reflected upon the impact of textile waste and recognized that we were part of the problem! Every year, about 92 million tons of garments end up in landfills, with the average US consumer discarding nearly 82 pounds of clothes. We are an organization that prides ourselves on solving problems and it is in that vein that we set out to reduce any potential waste from our largest cleanup event of the year! Of course, if you want to purchase a commemorative t-shirt to help us raise much needed funds, we would appreciate the support, but there is no obligation on your part to do so. To learn more about the impact of textile waste, check out the following resources:

10 Concerning Fast Fashion Waste Statistics

The true cost of colour: The impact of textile dyes on water systems

Many Thanks to Our 2026 Earth Day Cleanup Sponsors

2025 Earth Day Cleanup After Action Report

Freshwater Mussels – A Storymap

For an in-depth look at freshwater mussels and how these fascinating creatures make a lasting impact on the environment, see this Storymap. 

Why are mussels important?

Mussels are filter feeders. An adult freshwater mussel can filter 10-20 gallons of water per day. They are very efficient at filtering pollution and disease-causing bacteria like E. coli from the Anacostia River. By removing soil and other tiny particles from the water column, mussels help improve water clarity and create good conditions for underwater plants to grow. These plants provide habitat for a variety of other species. Even empty mussel shells become a tiny home for other bottom dwelling creatures like crayfish, snails, insects and small fish. The shells also provide plants and algae with something to grow on. By restoring mussel populations, we are helping improve water quality and enhance the underwater ecosystems of the Anacostia River.  Plus, mussels are bioindicators: if there is too much pollution, we will know because the mussels don’t survive.

Scientists have found about 300 species of freshwater mussels in the United States, with the highest diversity in the Southeast. Sixteen species have been found in Maryland, including at least eight in the Anacostia River (in both Maryland and the District), according to an assessment we conducted with the Maryland Department of Natural Resources.

How are freshwater mussels threatened?

Freshwater mussels are one of the groups of animals in greatest danger in North America. Seventy percent of species are listed as vulnerable, threatened or endangered. Sadly, scientists now consider 37 species extinct. Severe habitat destruction, water pollution, climate change, damming, invasive species and overuse of water for agriculture and other uses are responsible for the dramatic decline. Mussels live part of their lives attached to fish, and many of their host fish species are declining, too. 

AWS Accomplishments in Mussel Restoration

Since 2019, we have stocked over 38,000 freshwater mussels of five native species into the Anacostia River:

• Eastern lampmussel (Lampsilis radiata)
• Eastern elliptio (Elliptio complanata)
• Eastern floater (Pyganodon cataracta)
• Eastern pondmussel (Sagittunio nasutus)
• Alewife floater (Utterbackiana implicata)

Eastern pondmussels and Alewife floaters are considered species of greatest conservation need in both Maryland and the District. These 38,000 mussels will filter the equivalent of 427 Olympic-sized swimming pools each year. Our goal is to add more of these mussels to the river and improve their habitat so that more mussels will filter more water, improving the water clarity and helping the river’s ecosystems.

Freshwater Sponges

Freshwater sponges are one of the newest areas of research at AWS. For years, we saw sponges growing on mussel baskets, cages and shells, but didn’t know what they were.

While out on a mussel survey in the upper Northwest Branch, the restoration team saw a beautiful green creature growing on a rock. This creature just so happened to be a freshwater sponge. The team began seeing so many of them, so we decided to get a permit to collect samples. We sent them to a sponge expert in Michigan who uses a scanning electron microscope and DNA sequencing to identify them. So far, four different species have been identified from our Anacostia watershed (and a tidal Potomac River sample):

• Trochospongilla leidii
• Trochospongilla horrida  
• Ephydatia fluviatilis
• Eunapius fragilis

What are freshwater sponges?

Freshwater sponges are primitive aquatic animals that live attached to rocks, logs, concrete, metal or other surfaces. They live in lakes, rivers, streams, and wetlands. Like their marine cousins, freshwater sponges lack true tissues and organs. Their bodies are full of pores and channels through which water circulates. Like mussels, they are filter feeders, removing bacteria, algae, and organic particles from the water.  They can be identified by the shapes of microscopic parts called spicules, which form the sponge’s skeleton. The best spicules for identifying a sponge are found coating buds called gemmules. Gemmules are tough “survival capsules” that help sponges get through harsh environmental conditions. New sponges grow from gemmules when conditions improve. 

Why are freshwater sponges important?

As filter feeders, sponges help improve water quality. They are food for fish and other organisms, and provide habitats for other small river creatures. They can act as bioindicators, offering a glimpse into the health of an ecosystem. However, so little is known about them that the research we are doing is fairly novel. One of our goals is to help assess whether sponges could be used as bioindicators in macroinvertebrate sampling as sponges are relatively easy to identify by higher taxa (order/family) but not by species, which is normally the ID level required for this kind of sampling.

Stay up-to-date on #MusselPower!

We’ve done a series of blog posts about how our mussel program is going!  View all the blog posts about the project.

How can you help?

Our mussel restoration program can always use your financial support (donate here). You also can join our special team of mussel volunteers.

Our mussel work doesn’t normally require large groups of people, so we keep a list of interested volunteers and invite them to mussel monitoring and basket maintenance days. Volunteering may involve walking in boots or waders in mud and water, lifting weight (20-30 lbs) and other minor physical activities outdoors in hot or cold temperatures. 

Interested in involving your students in mussel restoration?  Visit our Mussel Power program page to learn more.

A natural filter for the Anacostia River

Why are wetlands important?

Wetlands behave like the kidneys of a river system by filtering, recycling and purifying the water of sediment, trash, nutrients and pollutants. Wetlands also provide a variety of other key ecosystem services such as restoring underground water supplies, flood control, shoreline stabilization, recreational opportunities, and high quality fish and wildlife habitat. Native wetland plants provide food and habitat to many songbirds, waterfowl, mammals, fish and other wildlife.

How are wetlands threatened?

Destruction, land use change, and development

Since the late 1800’s, much of the Anacostia River’s wetlands have been filled, dredged, paved or altered in other ways. The watershed has lost about 6,500 acres of wetland, according to the U.S. Environmental Protection Agency. These changes, and poor soil erosion control practices during construction, have increased the amount of sediment and pollution in the river. 

Invasive Species

From snakehead fish to yellow irises, aquatic species introduced from outside our region keep establishing in the watershed, causing a wide range of ecological impacts to wetlands and aquatic habitats. A non-migratory subspecies of Canada geese introduced in the mid-20th century devastated the river’s tidal marsh vegetation, particularly wild rice (Zizania aquatica), jeopardizing the marsh ecosystem. Government agencies have been controlling the goose population since 2016, and marshlands and wild rice are recovering.

An invasive insect called the emerald ash borer has destroyed much of the river’s ash tree populations, deeply changing the ecology of the forests along the main stem of the river. Without these trees along the banks, the river is susceptible to the colonization of invasive plant species, changes in water flows in these forested wetlands, increased stormwater runoff and more pollutants and sediment flowing into the river.

Invasive plants are among one of the most prevalent threats to our native ecosystems. These non-native species spread quickly and outcompete native plants for sunlight, nutrients, and space. As they take over, they reduce biodiversity, making it harder for native wildlife to find the food and habitat they depend on. With species like Porcelain Berry, Japanese Honeysuckle, Oriental Bittersweet and Kudzu to name a few, the watershed is overrun by these species. Many of these invasive vines will also cover and grow on top of native trees, killing them. This is why one of the main parts of our reforestation efforts is to also remove the vines that grow near and on the trees! 

Sea level rise and climate change

The Mid-Atlantic region is rapidly experiencing the effects of climate change and particularly sea level rise. Projections through the end of the century vary with emissions and climate scenarios, but for Washington, D.C., forecasts are for seas to rise about a foot by 2050 and between 2 and 3.4 feet by 2100. This will dramatically change the acreage and distribution of underwater plants and tidal marshes in the Anacostia River. Wetlands move inland as water levels rise, but in an urban area like the District, there is not much room to move, so they are in danger of being lost permanently.  

AWS Accomplishments in Wetland Restoration Efforts

In the last 15 years, AWS has done restoration work in more than 35 acres of mostly tidal wetlands in the Anacostia River. This includes control of invasive Phragmites reeds and revegetation with native wetland plants. The restoration team has mapped 26 acres of wild rice at Kingman Lake in 2025, which is a major improvement compared to the 20 acres mapped in 2020. 
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To combat the Canada goose problem, AWS had to fence off every single wetland planting area in the tidal Anacostia. With the help of the National Park Service, populations have been brought under control. We have been able to remove the fencing, which had become problematic trash traps. 

To combat the emerald ash borer devastation, AWS has planted more than 1,600 native trees from 16 species on 19 acres along the banks on the Maryland side of the Anacostia River. 

How can I help?

AWS wetland tree planting events usually take place during spring and fall each year, though special planting events may occur during other seasons. Volunteers can help us harvest wild rice seeds in the summer and sow them in the fall in mudballs. 

If you want to volunteer as an individual or in a group, visit our events calendar to see when our next scheduled event will take place.

According to the Anacostia Watershed Restoration Plan, the Anacostia River has lost 70% of its forest cover and 6,500 acres of wetlands since the 17th century. Presently, more than 70% of the watershed has been developed and impervious surfaces cover more than 25% of the watershed.

Since our founding in 1989, the Anacostia Watershed Society has been committed to increasing the Anacostia watershed’s forests, meadows, and wetlands by planting native species in degraded riparian corridors. Trees and plants help to reduce soil erosion, provide food and shelter for a variety of birds and animals, capture carbon emissions in the environment, and filter pollution caused by stormwater runoff. Improving habitat along the river advances our vision of a restored and climate resilient Anacostia and engages students and volunteers in hands-on efforts to restore the river, helping to increase environmental awareness and build support among community members for the Anacostia’s long-term protection.

Centuries ago, the Anacostia River was a broad, meandering waterway with more than 2,500 acres of wetlands. However, decades of deforestation, urbanization, and wetland loss have significantly degraded the river’s habitat and biodiversity. 

Brief History of Habitat and Biodiversity Loss

Habitat loss in the Anacostia River happened mainly because of rapid urbanization and human activity over the past century.

As urban areas expanded, forests and wetlands along the river were cleared to make space for roads, housing, and industry. Wetlands, which are critical habitats for fish, birds, and other wildlife, were especially affected because they were often drained or filled in.

Pollution also played a major role. Stormwater runoff from streets, construction sites, and factories carried sediment, trash, and chemicals into the river. This degraded water quality, making it harder for many species to survive. Excess sediment buried underwater habitats, while pollutants harmed aquatic life. The river was also altered physically through dredging and reinforcement to support navigation and flood control. These changes disrupted natural ecosystems and reduced biodiversity.

This was a major contributor to the loss of biodiversity. The populations of mussels, shad, and many other important natives declined rapidly. 

In short, habitat loss in the Anacostia River was caused by a combination of urban development, pollution, and modification of the river’s natural landscape. 

We are working to restore these important ecosystems back to health! Many of our programs work specifically to combat the damages that were done to our environment such as wetland tree plantings, vernal pool conservation, mussel propagation and climate change resilience projects are just a few of many. 

Learn more by visiting our Field Conservation and Restoration program pages:

• Freshwater Mussels and Sponges
• Vernal Pools
• Habitat Restoration
• Wetland Restoration
• River Smart Communities
• Pollution Reduction
• Earth Day Cleanup

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