The Mill Valley StreamKeepers publishes a newsletter to disseminate information about the StreamKeepers’ current projects, to announce planned events and activities, and to provide a forum for members or concerned citizens to express their thoughts and feelings about Mill Valley and its waterways.

To see past and recent issues the newsletter of the Mill Valley StreamKeepers, click on any of the links below:



Below are reprints of selected articles from past issues of our newsletter.
If you would like to suggest topics for articles, please contact us.

by Andy Peri

We at the Mill Valley StreamKeepers are committed to engaging members of Mill Valley’s community in activities that help protect Mill Valley’s spectacular natural beauty. We recognize the fundamental connection that exists throughout the watershed from the top of the ridges, down the canyons and hillslopes, through the stream channels and to the Bay.

Watersheds, or drainage basins as they are sometimes called, are the area that extends from the top of the ridges to the flat flood-plain regions near the Bay margins. They are unique geographic features because both sediment and water move exclusively within them. Any influence on either the sediment or the drainage system of watersheds results in down-stream effects; some adverse, some beneficial.

Human activities that are conducted in a wise manner can produce positive effects or at least minimize adverse effects on stream inhabitants and water quality in the lower watershed. However, activities that are done in ignorance or disregard of the watershed ecology can have very significant detrimental effects on water quality and stream habitat.
Disturbing large areas of soil during the rainy season, for example, can lead to fine sediment entering the stream, smothering the eggs of Steelhead which are listed as threatened under the Federal Endangered Species Act.

Mill Valley’s Arroyo Corte Madera creek, along with other Marin County streams, regularly experiences illegal dumping of paint, wet cement, herbicides, motor oil and other everyday toxic chemicals into storm drains (street gutters, etc.) which have devastating effects on aquatic life. Many people mistakenly believe that the water entering storm drain systems is treated. It is not. Storm drain water flows directly into creeks or the Bay.

The Mill Valley StreamKeepers would like to minimize activities in the watershed that have adverse effects on the streams and the water quality while working to restore previously degraded areas of the watershed. Our aim is to support members of the community in becoming active stewards of the watershed lands through volunteer opportunities, educational stream walks, our monthly meetings and public events. We are working with the City of Mill Valley, the County of Marin, and community watershed groups that share our enthusiasm for the well being of both the streams of Mill Valley’s watershed.

Mill Valley StreamKeeper Andy Peri worked with the North Bay Riparian Station, which supports watershed restoration and education in the North Bay. He has coordinated stream surveys with Mill Valley Watershed Project volunteers, and led Mill Valley residents on periodic Creek Walks in town.

by Lynn Jensen

We moved to Walnut Avenue in Mill Valley in 1972. We had been looking for a home on a level lot and we found just what we were looking for. In addition, it had a bonus of having Warner Creek running through our front yard and a bridge leading to our house.

As time went on, we developed an interest in our creek and found that it becomes a babbling brook in the summer and a raging torrent in the winter. During the rainy season, the creek sometimes floods the street for nearly half a block, filling the intersection of Walnut and Locust Avenues so deep that automobiles cannot get through. At the same time, flooding also occurs where the creek is too narrow to handle the flow and where there is a sharp curve in the creek. The velocity and power of the water can become great enough at times to move objects of considerable size.

Once a large concrete block was found in the creek after the water level subsided. Needless to say, we don’t cross our bridge during high water! In contrast, in late summer and fall our creek is only a few inches deep and dries up completely in our driest years.

For years after we moved, during the summer and early fall, hundreds of tiny frogs came out in the evening and congregated in the creek. Despite their size, they produced a chorus of loud croaks that could be heard a block away. Our neighborhood became used to their songs and enjoyed them.

We have noticed at times a film on the water, possibly from automobile oil that has killed the insects. We have seen the creek thickened with sediment. The frogs and tadpoles seem to have disappeared; we haven’t seen or heard them since noticing these disturbances to our creek.

We are pleased to see a growing awareness in our community of the conditions of our creeks. The StreamKeepers and other concerned organizations can make a real difference in the health of our watershed by educating our citizens about ways we all influence our creeks.
Mill Valley StreamKeeper Lynn Jensen was very concerned about the toxins and runoff that flow into creeks from our storm drains and destroy the habitat of frogs and other aquatic life. He shared the concerns of his local homeowner’s association, the Tamalpais Park Neighborhood Association, at StreamKeepers meetings.