Celebrating Reston’s Lakes: A Look Beneath the Surface on Lakes Appreciation Month

Contributed by Reston Environmental Advisory Committee

Water quality sampling at Lake Audubon in 2023. Photo by Ben Rhoades.

Reston is home to four picturesque man-made lakes—Lake Anne, Lake Audubon, Lake Thoreau, and Lake Newport—constructed between the 1960s and 1990s as part of the community’s original master plan. Spanning more than 125 acres, these lakes manage stormwater across a 5,600-acre watershed while providing scenic beauty, recreational opportunities, and habitat for wildlife. But beneath their calm surfaces, Reston’s lakes are facing increasing ecological stress. As we mark Lakes Appreciation Month this July, we’re reminded that protecting these resources is not just a matter of maintenance—it’s a shared responsibility.

In recent years, public health advisories have been issued at Lake Audubon (2018, 2021), Lake Thoreau (2023), and Lake Anne (2024), warning residents to avoid contact with the water and to keep pets away due to harmful algal blooms. These blooms are fueled by excess nutrients—particularly nitrogen and phosphorus—entering the water from lawn fertilizers, pet waste, and eroded soil. Algal blooms accelerate the natural aging process of lakes, known as eutrophication, in which nutrient overload leads to chronic algae growth, murky water, foul odors, and, eventually, lower oxygen levels that can harm fish and other aquatic life. Together, these impacts diminish the health, appearance, and recreational value of the lakes. Warmer summers and intense rainfall further contribute to bloom conditions, especially for blue-green algae (cyanobacteria), which can produce harmful toxins.

As lakes become more eutrophic, they also become more costly to restore. The Reston Association (RA) has responded with a range of management strategies, including lake-wide algaecide treatments to reduce algae growth and dredging operations to remove nutrient-rich sediments. RA also conducts ongoing water quality monitoring, invasive plant control, shoreline stabilization, and public education to help the lakes age more gracefully. These efforts are detailed in the most recent Reston Association Reston Association State of the Environment Report (RASER).

While RA leads many of these initiatives, residents play a crucial role in prevention:

• Pick up after your pets to reduce nutrient and bacteria runoff.

• Fertilize lawns responsibly. Avoid applying fertilizer just before rain—it often washes away, weakening your grass and fueling algae blooms downstream. Ideally, fertilize two to three days before a light rain, or during a dry period with light watering to help nutrients soak into the soil.

• Plant native vegetation along shorelines and in home landscapes. Deep-rooted native plants reduce flooding, prevent erosion, and filter nutrient-rich runoff, all while supporting local biodiversity.

• Leave the leaves or mulch them in place to return nutrients to the soil naturally.

Small, thoughtful actions make a big difference. By working together, we can keep Reston’s lakes clean, healthy, and vibrant for generations to come.