Little Otter Creek Watershed

Since the Addison County River Watch Collaborative began monitoring Little Otter Creek in 1997, it has recorded somewhat elevated E.coli, turbidity, and phosphorus levels. Classified as a cold-water Class-B stream, the lower reaches of Little Otter show characteristics more like a warm-water, marshy “slang”, as two branches of it are called by locals.

Little Otter Creek is listed by the State of Vermont as impaired for aesthetic reasons, aquatic life support, and contact recreation as a result of agricultural runoff and high E. coli counts from nine miles upstream to its mouth. It is also listed as impaired for aquatic life support from mile 16.4 to mile 15.4 as a result of agricultural runoff.

To explore interactive maps and gain an overview of the Little Otter Creek Watershed, click the image below:

 E. coli counts in Little Otter Creek consistently exceed the Vermont State Standard, increasing downstream to Middlebrook Road (LOC7.8), and then decreasing slightly to Route 7 in Ferrisburgh (LOC4.3). This pattern parallels both turbidity and phosphorus concentrations, and may reflect a need for improved farm management practices.

Phosphorus concentrations are high in Little Otter Creek as well as its tributary Mud Creek, reflecting erosion and agricultural runoff. Phosphorus transported by suspended sediments from erosion and runoff, and dissolved phosphorus from farms in need of improved management, increase downstream during periods of high flow.

For years 2010 and 2011, the Little Otter Creek watershed was the subject of focused monitoring, including a flow study to evaluate nutrient and sediment loading. Water quality data were used to calculate coarse estimates of phosphorus loading on a subwatershed basis as a means of prioritizing restoration and conservation efforts within the watershed.

Regional, state and federal partners (NRCS, Ducks Unlimited, Vermont Land Trust) are making use of these data with a focus on lands that drain to the creek north of Plank Road and east of Monkton Road. Conservation easements and Wetland Reserve Program projects are being implemented where landowners are willing. UVM Extension and Vermont Agency of Agriculture are also referencing ACRWC water quality data as they work with farmers in the watershed, including Large Farm and Medium Farm Operations, to implement improved agronomic practices such as livestock exclusion, cover cropping, increased buffers, and incorporation of manure.

Little Otter has, since prehistoric times, been a remarkably bountiful ecosystem. The mouth of this marshy stream was a favorite fishing and camping location for Native Americans. Local historians and authors Morris Glenn and Katherine Teetor wrote in their 2005 book, The Historic Thompson’s Point Fishing Ground, that even after local tribes moved to Canada during the Revolutionary War, they regularly returned to the mouth of Little Otter “In the summer to fish and gather rice and reeds well into the 20^th century.”