Addison County River Watch Collaborative

New Haven River at confluence with Muddy Branch, an ACRWC sample station (NHR2)

New Haven River at confluence with Muddy Branch, an ACRWC sample station (NHR2). Photo by Matt Witten


The Addison County River Watch Collaborative (ACRWC) was formed in late 1997 to unite ongoing stream-monitoring efforts by citizens in the Addison County region. Citizen monitoring efforts for these streams have involved various water quality measurements, including bacteria, pH, total phosphorus (TP), total nitrogen (TN) and water temperature.

Member groups of the collaborative have monitored the following stream sections: the Middlebury River and the middle section of Otter Creek, begun in 1989 by Otter Creek River Watch (a project of Otter Creek Audubon Society) and Middlebury Union High School; Lewis Creek, begun in 1992 by the Lewis Creek Association; New Haven River, begun in 1993 by New Haven River Watch (a project of New Haven River Anglers Association); and Little Otter Creek, begun in 1997 by The Watershed Center with assistance from Addison County Regional Planning Commission and Otter Creek Natural Resources Conservation District. In the summer of 2003, the Addison County Regional Planning Commission (ACRPC), and the Weybridge Conservation Commission (WCC) in partnership with Natural Resources Conservation Service (NRCS) and Middlebury Union High School (MUHS) partnered to gather reliable base-line water quality monitoring data on the Lemon Fair River in the Otter Creek Basin.

Prior to the efforts of these River Watch groups, there was little long-term information available regarding the health of these rivers. The groups believe that keeping ongoing records of water quality measures is necessary to create a profile of the status of these rivers and to understand how future changes in agricultural, residential, industrial, or recreational uses may affect them.

Addison County River Watch Collaborative (ACRWC) is one of a number of citizen water monitoring groups in Vermont whose volunteer members work to ensure the ecological integrity and the recreational viability of their communities’ watersheds.

Goals of the ACRWC:

  1. To monitor and assess the condition and uses of our local rivers, creeks, and streams over time
  2. To raise public awareness of and commitment to the ecological, economic, and social values and functions of our local rivers, creeks, and streams.
  3. To support and praise actions by landowners that improve the health and quality of our local rivers, creeks, and streams.

In combining their efforts, the partner groups are creating an integrated watershed approach to natural resources. This makes sense ecologically and will also, ideally, encourage greater citizen responsibility for the integrity of these watersheds.

 The Study Area


Otter Creek at Vergennes Falls

Otter Creek at Vergennes Falls. Photo by Matt Witten

All the watersheds in this report are considered by the Vermont Agency of Natural Resources to be part of the Otter Creek Basin, known as Vermont’s Basin 3, and drain a large portion of the middle Champlain Valley in Vermont. Lewis Creek and Little Otter Creek drain directly into Lake Champlain in Ferrisburgh and, where they join the lake (at their mouths), they share a 400-acre wetland complex with deep emergent marshes, a lakeshore floodplain, and bottomland forests. The Middlebury, New Haven, and Lemon Fair Rivers are tributaries to Otter Creek, which then drains into Lake Champlain, also in the town of Ferrisburgh. (Dead Creek, another major tributary to Otter Creek, has not been studied by the collaborative.)

These watersheds include forested mountains, agricultural lowlands, urban/residential areas, and industrial areas. The study area also includes municipal and industrial sewage treatment facilities, as well as power generation dams on some of the rivers. The streams are valued and used by local citizens and tourists for boating, swimming, and fishing, and the waters and the trees along the banks provide important habitat for a wide range of flora and fauna.

According to the Otter Creek Basin: Water Quality Assessment Report, published by the Vermont Agency of Natural Resources in June, 1998, the greatest threat to the streams in Basin 3 is sedimentation. This process occurs when many soil particles enter the water column. The second greatest threat to these streams is stream bank erosion, resulting from various land use practices, including the removal of streamside vegetation. Pathogens, such as E. coli bacteria, threaten the third greatest number of stream miles in this basin, and nutrients, including phosphorus, are the fourth greatest cause of impact. Other causes of water quality impairment include turbidity (cloudiness of the water), organic enrichment, suspended solids, and metals, such as mercury.

Citizen monitoring efforts for these streams over many years have focused primarily on E. coli bacteria counts, total phosphorus levels, pH, and water temperature, with the addition of total nitrogen, dissolved phosphorus, turbidity and total suspended solids in recent years.

For more information on the Addison County River Watch Collaborative, please contact Matthew Witten.

  • Recent ACRWC publications are available here or on the Lewis Creek Association’s web site here.

Addison County Regional Planning Commission | 14 Seminary Street Middlebury, VT 05753 | 802.388.3141 |

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