Dutch Hollow Brook Streambank Protection
Cayuga County Water Quality Management Agency
Basin Program Funds:
Dutch Hollow Brook has been identified as one of three major contributors of
significant amounts of sediment, nutrient, and pesticide loading into Owasco
Lake. Sediment deposits result in turbidity problems for the water supply and
excessive weed growth. In addition, sedimentation from bank erosion has clogged
the stream's channel resulting in winter ice jamming and flooding.
The Dutch Hollow Brook Streambank Protection project seeks to improve and protect
the quality of Owasco Lake, a major source of drinking water in Cayuga County,
by controlling nonpoint source pollution originating from Dutch Hollow Brook,
a tributary to the lake.
A 1974 study by the Soil Conservation Service shows that Dutch Hollow Brook's
131 miles contributes 64.6 tons of soil per bank mile per year. Bank heights
range from two feet to 300 feet high with a 5:1 feet slope, and is less than
3/4 miles from the mouth of Owasco Lake. Past studies have indicated that 60% of sediments entering the lake come from within the first mile of its
After a number of meetings with the property owner of the project site, the
site was surveyed and a design was drawn up that would best solve the erosion
problems. The following Best Management Practices (BMPs) were then implemented.
- 180 feet of rip rap was placed along the streambank and heavy debris was
removed at the base of the bank
- A small retention pond was dug at the base of the bank for sediment storage
- Underground drainage tiles were laid to divert groundwater
- The steep bank was terraced, seeded, and mulched in the fall of 1994 and
the summer of 1995
By removing the south gravel bar, heavy debris at the foot of the bank, and
dredging the channel to a depth of 14 feet. The stream channel capacity was
increased by 50%. The slope of the bank was reduced to 3:1 feet by forming two
terraces. Flood prevention benefits were observed during the spring of 1995
along with reduced soil erosion.
The quantity of soil saved has been approximately six tons per 180 feet. This
is due to the former steepness of the bank and the use of the retention pond.
With the reduction of soil loss, 198 pounds of potassium, 26.4 pounds of phosphorous
and 39.6 pounds of nitrogen were saved.
Future dredging of the pond will have to be done as needed and the bank will
be monitored for any future maintenance or reseeding needs.
Contact: Cayuga County Water Quality Management Agency, (315) 252-4171