Holiday week enjoyment of the Mad River in Waitsfield.

Sampling results from the third round of Friends of the Mad River’s 2019 Mad River Watch water quality monitoring show no sites with unfavorable E. coli levels as of Monday morning, July 8. Saturday afternoon thunderstorms broke up an otherwise hot and muggy July Fourth holiday week and washed most pollutants off the landscape, into the water and downstream prior to sampling on Monday morning.

Water temperatures on Monday ranged from 55F in the headwaters to 67F along the Moretown Main Stem, with a high of 73F at Blueberry Lake. Many community members and visitors took advantage of this cool water temperature and took a break from the holiday week’s heat in the Mad River. Swim holes across The Valley were dotted with swimmers, sunbathers and river enthusiasts of all ages.


At the time of sampling on Monday morning, the river's discharge (volume per second) was 195 cubic feet per second (cfs) at the U.S. Geological Service flow gage in Moretown, having dropped from a high of 562 cfs at 8 p.m. on Saturday evening after thunderstorms moved through the area. The flow condition of the Mad River at the time of sampling Monday morning was low and steady (LS). The mean flow for this date over the last 90 years is 127 cfs; the water was only slightly higher than usual at this time of year.

Remember that rains can cause E. coli levels to fluctuate, even on a daily basis, as water carrying pathogens moves down the watershed. Saturday’s rain most definitely washed pollutants into the water – Friends’ E. coli sampling results are only a snapshot in time intended to give you a sense of the conditions that lead to high pathogen levels in the water so you can be informed. You are your best protector – use common sense and don't swim for several days after a rain. It is estimated that at the level of 235 colonies E. coli per 100 mL water, approximately eight out of every 1,000 swimmers are likely to contract a waterborne illness related to fecal contamination.


As part of the Mad River Watch program, community volunteers collect samples of water on six occasions throughout the summer from about three dozen river and tributary sites. Then, the Friends’ lab and Vermont’s Agriculture and Environmental Laboratory analyze the samples’ bacteria and nutrient levels. Friends posts E. coli data in The Valley Reporter, on its Facebook page and websites, and on signs at 10 popular swim holes across The Valley so that people have information to make their own recreational health decisions. In addition to E. coli data, Friends posts total phosphorus and nitrogen data on its website at summer’s end when received back from the state lab. Over the decades, Friends has used Mad River Watch data to guide many successful cleanup efforts.

This week’s volunteers include Charlie Baldwin, Sally Boudreau, Annie and Jula Fender, Rick Hungerford, Ruth and Steve Lacey, Susanne and George Schaefer, Chris Shaw, Michael Ware, Paula Baldwin and Julie and Ingrid Westervelt.

For more information about E. coli and the Mad River Watch program visit Friends of the Mad River is a community-supported organization committed to healthy land, clean water and a vibrant community. Mad River Watch and other important programs depend on the generosity of community members; learn how to become a member and donate securely online on the Friends’ website.

Mad River Watch July 11, 2019