5 Feb, 2012 Author: Glorianna Davenport

(see more pictures below)

Survey base station in field of little blue-stem grass

Neighbors are asking: What is happening to Tidmarsh? What will the property become? Behind these questions lies a nagging anxiety: how will the change (negatively) impact me? We all understand that the promise of change can be unsettling, particularly when it is imminent, close by, and lacks predictability.

Unfortunately we do not have a pat answer. Tidmarsh Farms is a large property; it encompasses one-tenth of the watershed and 1/2 the length of Beaver Dam Brook. With some caveats, we are looking toward making a major portion of the property into a nature preserve that will provide people with access to a natural landscape for quiet enjoyment; diverse habitats for wildlife including plant, bird and fish populations; and a protective flood plain to moderate the unpredictable events that nature provides. As always the devil is in the detail.

To move on to detail, we plan to restore the waterway and flood plain. For almost 200 years, Beaver Dam Brook has been manipulated, first by entrepreneurs who needed water power to run a grist mill and cotton factory, both located where the brook exits the Tidmarsh Farms property on Route 3A; and later by others who believed they could reshape the waterway for the purpose of farming cranberries.

The original dam that was built to run the mills and the factory in the mid-1800's backed water up on the Tidmarsh flood plain, creating an oddly shaped pond, which you can see if you look at the old map on the wall of the Plymouth Library. When this land was converted for cranberry farming, the waterway was dramatically altered. Cranberries are grown, with the help of controlled water levels, sand and sunlight, as a mono-culture. The first step was to build the bogs: in the process water was held back in reservoirs, the bog surface was flattened, ditches were created to allow surface water to evenly reach the roots, and a significant quantity of sand was applied across the entire surface allowing the runners to easily root. As the best practice evolved, 1/2 inch of sand would be applied across the bog surface every three years, and recommended doses of fertilizer, herbicide and, pesticides were applied as required. Meanwhile, winter floods reduced winter kill, and, by mid century, harvest flooding created significant efficiencies.

All these manipulative practices created stress to the natural movement of water, sediment and micro-organisms. The restoration is focused on relieving this stress: reconstructing a meandering brook for the natural flow of water, where possible removing sand, filling man-made channels, planting some native species as appropriate and eradicating some invasive species. Once this work is completed, the waterway and flood plain will be left to evolve naturally.

Before we can design this restoration, we need to know more about the landscape. Rather like a human medical exam, we need to probe and sample the elements. How much sand sits on how much peat? How does the ground water flow? How deep is the channel, and how high is the bank? Much of this sampling and probing was done in January. Once the collected data has been analyzed and used to model the hydrology of the site, we will articulate and discuss design options with our partners and our neighbors as well as with the town and other regulatory agencies. If you are a neighbor and wish to meet with us directly, prior to our holding public forums, please email us at tidmarshfarms.com

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Collecting the data: Jan 19, Jan 24-27, 2012

Thanks to the whole team

Coming next: the Ground penetrating radar survey!