A team of scientists at The Nature Conservancy is tracking water in some key places in Maryland using high-resolution mapping technology called LiDAR (for Light Detection And Ranging). Their goal is to maximize conservation investments designed to improve water quality in agricultural landscapes where excess nutrient and sediment delivery threaten aquatic diversity.
Their efforts are focused on the Pocomoke River watershed and Talbot County on the Eastern Shore, as well as Washington, Allegany, and Frederick counties in western Maryland.
“We want to reduce surface water runoff and improve nutrient retention without losing agricultural land,” said Kathleen Boomer, Conservancy watershed scientist. “The idea is to intercept water high in nutrients and sediments with restored wetlands or other conservation practices. We use the LIDAR data to help us identify areas where these practices will have the greatest, most cost-effective benefits to water quality.”
Tracking water may sound easy, but it isn’t. Water interacts with the ground in an intricate manner; slight changes in elevation can change how water acts. Researchers also have no direct information about how water moves below the land surface. In a method she pioneered, Boomer uses high-resolution topography maps derived from LiDAR to identify areas where restored wetlands can enhance natural filter processes that improve water quality. Using expert knowledge of how landscape and water interact, scientists can pinpoint where water might naturally drain, flood, and pool.
Wetlands naturally filter sediments, nitrogen, and phosphorous, which are essential to living organisms, but become a problem when in excess. Once they know where the water is and how it moves, conservationists can target land areas that transmit nutrient- and sediment-enriched waters to our river systems as priority locations for wetland restoration. The Nature Conservancy then works with local landowners in designing and implementing projects, offering financial and logistical support, and evaluating the effects of projects.
“The Nature Conservancy has a very strong history of working collaboratively with landowners and stakeholders to find solutions,” said Amy Jacobs, watershed restoration director for The Nature Conservancy in Maryland/DC. “We want to meet the needs of the agricultural community, and improve water quality, which supports humans and nature.”
In addition to providing water quality benefits, wetlands provide wildlife habitat, store floodwater and sequester atmospheric carbon. While LiDAR has been used before to map watersheds, using that information to target wetland conservation efforts is a novel Conservancy initiative.
An interdisciplinary, science-based approach to targeting conservation solutions helps The Nature Conservancy maximize the efficiency and effectiveness of conservation efforts. In some areas, such as flat land used primarily for timber and recreation along the Pocomoke River, that means breaching artificial levees to create floodplains for water during storms. When water overflows a stream bank into a flood plain, it settles there, filtering out nitrates, phosphorous, and sediment, and slowly flows back in the waterway, preventing exaggerated flooding downstream.
The Nature Conservancy in Pennsylvania is doing similar work on the Susquehanna watershed. The Nature Conservancy hopes this method helps inform conservation efforts elsewhere in the region and the country.
The Nature Conservancy is a leading conservation organization working around the world to protect ecologically important lands and waters for nature and people. The Conservancy and its more than 1 million members have protected nearly 120 million acres worldwide. Visit The Nature Conservancy on the Web at www.nature.org.
Lindsay Renick Mayer
301-897-8570, ext. 224