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MDE, the Maryland Department of Agriculture (MDA), the Natural Resources Conservation Service (NRCS), and the Chesapeake Bay Foundation partnered with the owners of Hunting Lotte Farm in Frederick County to demonstrate that using best management practices (BMPs) on agricultural land can yield significant water quality improvements.
The conversion of natural land to agricultural or urban can have negative environmental consequences, including increased nutrient or sediment runoff that can damage local and downstream waters. However, the application of BMPs, such as erosion minimization techniques, nutrient management, or control of stormwater runoff, are aimed at mitigating such negative impacts. MDE works with a number of stakeholders and sister agencies to promote effective BMP applications in watersheds throughout the state. Recently implemented agricultural BMPs in a small tributary to Lake Linganore have already produced measurable in-stream habitat and water quality improvements.
Lake Linganore is a manmade impoundment located in Frederick County along Linganore Creek, a tributary of the Lower Monocacy River (Figure 1). Lake waters drain to the Monocacy River, then meander to the Potomac River, and finally reach the Chesapeake Bay. The majority of the land area within the Lake Linganore watershed consists of agricultural (approximately 40 percent) and urban (approximately 30 percent) land uses. Many of the tributary streams within this watershed have been negatively impacted by their close proximity to extensive agricultural applications and relatively new suburban development.
In the 1996 303(d) List of Impaired Waters, MDE identified Lake Linganore as impaired by nutrient and sediment nonpoint source runoff. In 2003, Total Maximum Daily Loads (TMDLs) of phosphorus and sediments were developed and subsequently approved by the U.S. Environmental Protection Agency (EPA) for the Lake Linganore watershed to address the 1996 nutrient and sediment impairments. A TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of that load among the various sources of that pollutant. The Lake Linganore TMDLs call for substantial phosphorus and sediment reductions needed to support the designated uses of the lake. MDE is currently working on additional nutrient and sediment TMDLs for the remainder of the Lower Monocacy River watershed.
In order to meet the target nutrient and sediment loads established within the TMDLs, the entire watershed has been targeted by the MDA for assistance to local farmers interested in implementing BMPs. One of the projects focused on a small, unnamed headwater tributary to Bens Branch located upstream of Lake Linganore. The tributary is surrounded by the Hunting Lotte Farm, a 450-acre crop and livestock farm with about 150 head of Black Angus cattle on about 80 acres of pasture. The crops include corn for silage, grain, wheat, soybeans, and mixed hay. In 2006, prior to BMP installation, the stream’s riparian zone was part of a cattle pasture that provided the livestock with unrestricted access to the stream (Figure 2).
As part of the restoration project, the farm owner invested nearly $100,000 in BMPs, of which about $79,000 came from grant assistance, to provide riparian buffer protection primarily via stream fencing and tree planting. Grant funds for the BMPs came from:
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Maryland Agricultural Cost Share (MACS): about $57,000,
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Conservation Reserve Enhancement Program (CREP): about $19,400,
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Chesapeake Bay Foundation (CBF): nearly $2,600.
The BMPs included more than 8,800 feet of fencing, three spring developments to replace in-stream cattle watering, improvements to three heavy use areas, two stream crossings, and plantings of over nine acres of cool season grasses.
To track anticipated improvements in water quality conditions and aquatic health for this and other BMP implementation projects, MDE’s Targeted Watershed Project uses 319(h) funds to pay for the technical work and analysis required to conduct the appropriate follow up monitoring. Three general types of information are being collected as part of this monitoring effort:
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quarterly in-stream water quality monitoring – to track changes in nutrient levels,
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annual quantitative stream channel surveys – to track substrate changes,
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periodic sampling of in-stream aquatic life (benthic macroinvertebrates) – to track changes in the local biological community.
While it is too early to quantify the effects of the project on nitrogen levels and the general health of the local aquatic community, initial monitoring results indicate that riparian vegetation has already began to revert back to its natural conditions (Figure 3). This vegetation provides extensive summer stream shading, which helps moderate in-stream water temperature, a key factor in the composition and productivity of a healthy stream system. Stream bank stability is much improved, and the percentage of a desirable in-stream gravel substrate has increased, while the sand/mud substrate has decreased. Phosphorus concentrations have also been declining, indicating a decrease in the amount of sediment entering the stream due to erosion from the surrounding agricultural fields (Figure 4). MDE is very pleased with these outcomes and plans to continue promoting similar measures in other watersheds throughout the State.
Questions relating to this initiative can be directed to:
Ken Shanks
Maryland Department of the Environment
Kenneth.Shanks@maryland.gov
410-537-4216
Dwight Dotterer, Ag. Assessment Planner
Maryland Department of Agriculture, Resource Conservation
Dwight.Dotterer@md.nacdnet.net
301-694-9290 ext. 130
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