The Appomattox River Is Getting Muddier, And The Causes Are Not Clear

Annapolis MD

03 June, 2022

10:24 AM

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By Jeremy Cox, the Chesapeake Bay Journal May 31, 2022 As the James Riverkeeper, it's Jamie Brunkow's job to know what's going on in his 10,000-square-mile watershed. That includes the Appomattox River, a ribbon of water that flows into the James about 80 miles above its confluence with the Chesapeake Bay. But he admits that the latest update about its water quality from the U.S. Geologic Survey left him baffled and concerned. The agency reports annually on trends for nitrogen, phosphorus and sediment for nine major Chesapeake rivers. The USGS findings were unusually encouraging in 2021, showing improvement in the estuary's three largest rivers: the James, Potomac and Susquehanna. Declines were observed in several smaller tributaries, but the Appomattox was the only one backsliding on all three contaminants — as far back as 1985. "I really don't know [why]," Brunkow said "[The numbers] stand out on the chart, for sure. It's a concerning trend when we see improvements elsewhere, and it needs more exploration to find out what's going on there." Brunkhow isn't alone. No one seems to know what's behind the river's decline. But theories abound. "We haven't come up with the answer on the Appomattox," said Doug Moyer, a USGS hydrologist based in Richmond. "We have a lot of hypotheses. Is it the reservoir? Is it upstream? Is it something else that isn't factored in? The answer is probably all of the above. It's all interconnected." The only thing that's certain, Moyer added, is: "Change is afoot. Something is going on." The Appomattox may be best known as the backdrop for Confederate Gen. Robert E. Lee's surrender to Union forces, marking the end of the Civil War. The nearly 160-mile river anchors much of the southern boundary of the Chesapeake watershed, but it tends to be viewed as a backwater by Bay researchers and activists, Moyer said. "It's certainly the little brother to the big three — the Susquehanna, the Potomac and the James," he said. The science agrees. The Susquehanna, for example, is a much larger contributor of nutrients and sediment to the Bay, pumping about 150 million pounds of nitrogen into the estuary per year at the Conowingo Dam, according to the Chesapeake Bay Program, a multistate and federal partnership. The Appomattox, by contrast, only generates about 1.5 million pounds. The Appomattox's smaller drainage area plays a role. So does the milder weather in southern Virginia, which leads to longer growing seasons and greater nutrient uptake by plants, Moyer said. Around the Bay, restoration funding and public attention tend to gravitate toward the tributaries with the heftiest pollution loads. That makes sense when the goal is getting the biggest bang for the buck in cleaning up the Bay, Moyer said. But it can also create a class of have-nots, which tend to be smaller, mostly rural watersheds. Like the Appomattox. The USGS nutrient and sediment reporting system is one of the most closely watched indicators of the Bay watershed's health. The agency has collected data at each river's freshwater endpoint since at least 1985, but the data alone don't explain the causes of the trends. "It's at the end of the pipe," Moyer said. "We don't know where the material came in." But he has a strong suspicion. The USGS water-sampling station on the Appomattox lies a short distance downstream from Brasfield Dam. When completed in 1968, the wall of concrete flooded thousands of acres of farmland, transforming a 12-mile portion of the Appomattox from a narrow, free-flowing stream into a sluggish drinking water reservoir. For the first few decades of its life, the impoundment acted like a giant pollution sponge, Moyer said. The decelerated flows above the dam — in what is now called Lake Chesdin — allowed nutrients and sediment to drift to the bottom instead of continuing their journey downstream to the James and the Chesapeake as they once had. That led to clearer, cleaner water below the dam at the USGS station. But that is no longer the case. Moyer thinks it's because the lake is getting filled up with mud and is losing its capacity to trap pollutants. The monitoring station's 37-year record of sediment data depicts a river in decline, he said. From 1985 to 1993, with the reservoir apparently in good form, the annual sediment total declined 20%, hitting an all-time low of 32.6 million pounds. Since then, the water has become muddier with almost every passing year. By 2018, more than 43 million pounds of sediment were gushing down the river, nearly 3 million more pounds than in 1985. "All of a sudden, we're starting to see a greater release of sediment from the Appomattox," Moyer said. The situation mirrors the Susquehanna River, he added. There, an impoundment above the Conowingo Dam shielded the Bay from a full onslaught of sediment and nutrients for decades until it lost nearly all of its pollution-trapping ability. Lake Chesdin isn't quite there yet, said Robert Wilson, executive director of the Appomattox River Water Authority, which operates the reservoir. Since its creation more than 50 years ago, the lake has lost about 10% of its water-holding capacity from the sediment buildup on its bottom —not nearly fast enough to warrant concern, Wilson said. But the land that surrounds the Appomattox is changing. Forests are being cut down to make way for subdivisions. An analysis of the watershed conducted by Mississippi State University researcher Kristina Delia shows that from 1992 to 2016, the watershed lost nearly 200 square miles of forested land and gained about 70 square miles of housing developments. "It is clear that forested area went down in the 30-year study period, which would imply higher runoff of sediment into the river," Delia said. Alecia Daves-Johnson, a founder of the advocacy group Friends of the Appomattox River, said she can tell something is wrong with the river just by looking at it. "When we have rain events, the Appomattox just runs muddy and brown," she said. "And I think, 'Where is all this sediment coming from?'" The Chesapeake Bay Journal is a nonprofit news organization covering environmental issues in the Bay region. Sign up for a free subscription at BayJournal.com.