Watershed Management Key to Success of Powder Creek Reservoir Project
Article by Richard Webster
From a vantage point on a slope overlooking Powder Creek Reservoir, nothing gives the appearance of anything different or unusual about the Dixon County reservoir. There are many similar reservoirs in eastern Nebraska designed for dual flood control and recreation functions. The typical problems facing reservoirs in an agricultural landscape such as eastern Nebraska were well documented as planning began for the Powder Creek Reservoir. The decision to confront these problems (water quality degradation from sediment, nutrients, and pesticides) through watershed management planning prior to construction is what distinguishes this reservoir from most others.
Structure 31-20A, better known as Powder Creek Reservoir, is located 4.5 miles south and 2.5 miles east of Newcastle, Nebraska. The 107-acre reservoir and surrounding park area are available for outdoor activities including fishing, hunting, and hiking. The dam across Powder Creek was completed in 2002, but water quality planning efforts began years earlier in 1998. Planning focused on three major components: (1) preliminary water quality planning; (2) development of in-lake pollution control measures; and (3) formation of a watershed management plan.
‘The Lewis & Clark Natural Resources District was one of the first Natural Resources Districts pushed to develop a watershed management plan as part of the approval process for funding through the Resources Development Fund,” said Tom Moser, Lewis and Clark Natural Resources District (NRD) Manager. “After a certain amount of grumbling we plunged into the community-based planning process with help from the Natural Resources Conservation Service and the Nemaha NRD.
“To our surprise, despite project opposition we had a good response from landowners and an even better response from agencies. The Game & Parks Commission and the Department of Environmental Quality provided quality support and funding to put together a plan and follow through on implementation. This was an area of hard sell on conservation, but a good coordinator and Conservation Reserve Program bonus incentives made it hard to say no.”
The development of a plan to soundly manage the watershed’s 7375 acres began in 2000. The plan was developed using the Department of Environmental Quality’s community-based planning approach (see related article). Issues and concerns identified by current and future watershed stakeholders representing urban, agriculture, and recreation interests drove watershed protection efforts. Public information meetings were held, and a local watershed advisory council was established. The council assisted in developing a plan to protect the reservoir. The plan, finalized in 2003, identified various methods to protect water quality including information and education programs, and the implementation of management practices on agricultural lands.
“Watershed management planning was an essential part of the overall planning for this project,” said Paul Brakhage, Environmental Assistance Coordinator with the Department of Environmental Quality’s Surface Water Unit. “Maintaining what has been achieved at the Powder Creek Reservoir not only depends on in-lake controls, but also sound management of the surrounding watershed.”
Land treatment measures that were adopted and/or constructed in the watershed include:
No-till farming – 2105 acres;
Cropland to grass conversion – 640 acres;
Wildlife habitat – 249 acres;
Filter strips and waterways – 79 acres;
Stream bank stabilization – 1 acre;
Dam rehabilitation projects – 6; and
New grade stabilization structures – 2.
Despite extensive preventive measures implemented in the Powder Creek watershed, runoff of sediment could never be completely controlled. To further address sediment entering the reservoir, protect water quality, and enhance wildlife habitat, in-lake measures were constructed. A two-celled sediment basin was constructed in the upper end of the reservoir. Islands, cove enhancements, scallops (open water areas), shoals, vegetative barriers, fish spawning beds, and selective deepening were employed to protect the lake water quality and enhance habitat.
“The results have been all positive,” Tom Moser said. “We were successful in establishing over 80 percent proper land treatment on 7600 acres and have lake water clarity that averaged five feet in 2004, which was twice our goal.”
Compared to pre-construction estimates of runoff in the Powder Creek watershed, sediment has been reduced by 79 percent, phosphorus by 72 percent, and nitrogen by 67 percent. While monitoring at the lake has focused on sediment and nutrients, the management practices implemented in the watershed also reduce the amounts of other pollutants, such as pesticides and bacteria.
“The water quality of Powder Creek Reservoir is reflective of improved watershed conditions,” said Paul Brakhage. “Phosphorus in the lake has remained low, algae production is minimal, and water clarity continues to be outstanding.”
Since aquatic species respond directly to water quality, the answer to one question may give the final word on how well watershed management has improved water quality: how is the fishing?
The proof of success came during a fishing trip with his sons, Tom Moser said. “We caught over forty 8 inch bluegill.”
A Look to the Future
It has long been recognized that prevention is less costly than remediation. The Powder Creek Reservoir project provides an example of how powerful prevention can be. The reservoir was projected to have a lifespan of 42 years if no sediment reduction measures were implemented in the reservoir’s watershed. With extensive land treatment and sediment reduction measures in place, sediment flow into the reservoir has been significantly reduced. At the current rate of sedimentation, the reservoir has a projected lifespan of over 200 years (beyond the year 2200). It is hard to imagine what northeast Nebraska will look like in 200 years, but the Powder Creek Reservoir may still exist as an unassuming monument to proactive watershed management.
Powder Creek Reservoir Facts
Location: Dixon County, 2.5 miles east and 4.5 miles south of Newcastle, Nebraska
Reservoir size: 107 acres
Watershed size: 7375 acres
Landowner participation rate: 67% (31 of 46)
Project cost: $1,078,990
Project sponsor: Lewis and Clark Natural Resources District
Project partners: USDA Natural Resources Conservation Service, Nebraska Department of Natural Resources, Nebraska Game and Parks Commission, Nebraska Environmental Trust, U.S. Environmental Protection Agency, Nebraska Department of Environmental Quality, Olsson Associates, watershed stakeholders
The Community Based Planning Process
The Department of Environmental Quality and the USDA Natural Resources Conservation Service developed the Community Based Planning Process as a locally driven approach to solving water quality problems. The process utilizes technical experts and watershed residents to develop local solutions to local problems in both urban and rural settings.
By involving local citizens in the development of goals, objectives, applicable management efforts, and the specific cost-share/incentive programs, the potential for success is much greater. The Community Based Planning Process is accomplished through a series of public meetings and interactive sessions between a Technical Advisory Committee and Watershed Advisory Council established for the project area.
For more information about Community Based Planning, contact: Paul Brakhage email@example.com, (402) 471-4224) or Elbert Traylor
firstname.lastname@example.org , (402) 471-2585).
Nebraska Department of Environmental Quality
1200 "N" Street, Suite 400
P.O. Box 98922
Lincoln, Nebraska 68509