Water Closet for January 13, 2017

[pullquote]”In constructing this system over almost two decades they have provided shallow, sunny open ponds for other animals, a pattern replicated countless times in the northeast now the beavers are back. “[/pullquote]The Cudhea-Prichard family of Middleton and beyond have for decades provided conservation land for plants, animals and for us to visit. Three generations of the family have given about 500 acres in Middleton to the town, the state and Greenbelt. On the last Friday of 2016 the Council of Aging/Conservation Commission hikers walked some of these conservation lands on an inch of glistening new snow under trees whose twigs, branches and trunks were decorated with coatings of sparkling ice. It had rained, cooled and snowed in the night. The results were played on by sunlight as the intrepid group hiked to the Cudheas’ Cottage on Prichards Pond and then on to a 165 foot long, six foot high, concrete dam that was built early last century by Charles Prichard. The dam across Boston Brook resulted in a one-third mile long “Pleasure Pond” for his family. During the great Mother’s Day Flood of 2006 a 30 x 2 x 2 feet section of the dam was torn from the top. The pond level fell 2 feet. That fall the beavers who occupied the pond built a new 36 foot long arc just above the breach which restored the water level to where it had been. Each fall since they have replaced their section when needed.

This, the fourth dam below three dams above that cross Cudhea Crick, was built this fall. The surface of the three acre impoundment above it is four feet higher than that of the brook below. – Pamela Hartman photo

The man-made beaver-patched structure was not the hikers’ goal. Three hundred feet downstream from Prichards Dam a tributary enters Boston Brook from the north. The Middleton Stream Team dubbed this four-fifths mile long brook Cudheas’ Crick. The rough narrow stream drops 40 feet from its headwater swamp en route to Boston Brook. The hikers turned north and trudged along the west ridge of the crick’s valley headed upstream for a system of four beaver dams that cross the crick in its upper 1000 feet. The use of the words valley and ridge bring to mind mountainous terrain. The ridges flanking this crick are only 30 to 60 feet above the brook’s floodplain, which is only a few hundred feet wide at its widest parts. No one except perhaps Stream Teamers would even call this wrinkle in the topography a “valley.” The terrain is typical of glacier- sculpted hills of ledge and sediment with drainages down between them. In the livestock grazing days the treeless ridge-valley topography in plain view was probably much more appreciated. Now the whole northern part of town embracing the crick’s watershed is shaded by patches of mature pines and many hardwoods, the latter mostly oaks. Before the beavers returned in the mid 1990s after a hiatus of three hundred years their present shallow impoundments called “beaver meadows” were red maple swamps. To those who see trees as only trees the wet lowlands were just woods. In the winter the lack of leaves give admirers a greater idea of what the rough pastures were like before the trees returned.

This beaver lodge in a 50 acre impoundment above four dams has housed 4 to 6 occupants each year. Generations of beavers have been building and maintaining a series of dams in Cudhea Crick since 2003. Before the beavers the impoundment was a shady red maple swamp. The year-round-water killed the maples; some of their still standing corpses are seen here. – Pamela Hartman photo

Because of the rough nature of the boulder strewn land the old hikers proceeded with care. Almost 400 hundred years ago the English came with hard-hoofed livestock who thrived in the savannah-like land near the coast that had been kept open perhaps for millennia by yearly Indian fires. Sharp hooves and close grazing endangered the thin eight to twelve inches of topsoil that had accumulated on the uplands for 10,000 years since the retreat of the glacier. The black organic soil is much thicker in the lowlands. In overgrazed places of upland the runoff from heavy rains picked up the hoof-stirred loam and carried it down slope where it settled in the wetlands. Many of the rougher higher areas in our towns have little topsoil hence ledges and the exposed boulders left by the glacier are readily seen. It was not like this when the Indians, not cursed by livestock, hunted in the savannah and engaged in agriculture in the river bottoms here. Often in the 17th century free ranging hogs and cattle caused serious problems for both colonists and the few surviving Indians. Many complaints at selectmen meetings had to do with the voracious grazers and soil breakers. The forest is back; the livestock are gone. In undeveloped areas new topsoil very slowly forms from rotting leaves, twigs, and fallen trees. Along streams such as sections of Cudhea’s Crick, fast flow has carried sediment on down to larger brooks and the slow flowing rivers. The floodplain along steeper, faster flowing sections has little muck and many exposed boulders where bushes and briars thrive among the trees. The walkers stayed on the rough slopes to the west as they slowly proceeded northward up the valley.

Three of a series of four dams across Cudhea Crick. Dams hold water in watersheds as well as providing rich wildlife habitat. – Donna Bambury photo

About a fifth of a mile from the headwater wetland they encountered the last to be built dam across a narrow place in the channel. The 25 foot wide structure was built this past fall. The head, vertical distance between the new pond’s surface above the dam and the brook’s surface below, is three feet; the 500 foot long impoundment formed above it covers about two acres. Around and over moss and lichen covered rocks the now tired hikers moved carefully on. After 250 more feet a familiar well-maintained dam 20 feet long crosses the crick. This dam’s head is one foot, its impoundment one-tenth an acre. Then 60 feet further on is yet another dam 40 feet long and three feet high. Its height had been increased in the fall when many beaver dams are raised a bit. The resulting pond above it covers three-fourths acre. And finally our main goal on such hikes up Cudhea Crick hove into view. It is an 80 foot long dam that we’ve admired since the beginning of the millennium. This was the first dam in this drainage to be built in modern times. Every few years the furry engineers and contractors add a few inches; it is now six or more feet deep. Along its muddy top and downstream slope is a thicket of pepper bushes and other water loving plants. The first logs and sticks used to make the dam have rotted and become part of an earthen structure 12 feet wide at its base. New branches are added as needed on the downstream side each year. More mud is plastered on the upstream gentle slope. Ten years ago after a substantial rain the old Closeteer found a two foot wide notch one foot deep, freshly cut in the dam’s top center. The beavers’ lodge 200 feet upstream in the dam’s 60 acre or so impoundment had been in danger of having its apartment floor flooded. The inhabitants went forth and notched the dam to lower the water to a depth a few inches below their floor. We wonder what language or signs are used to organize such actions.

Cudhea Crick dam. Beavers often make them higher in the fall. – Donna Bambury photo

This 1000 foot stretch of crick draining 250 or so acres of watershed has a series of dams holding water back so that the 50 pound rodent engineers and families can safely swim and float food branches and others for dam and lodge construction, place to place. In the winter due to higher water there is room beneath the ice to swim in. In constructing this system over almost two decades they have provided shallow, sunny open ponds for other animals, a pattern replicated countless times in the northeast now the beavers are back. At times during spring and fall visits, we’ll spook hundreds of migrating ducks resting and feeding. The list of animals including birds, mammals, amphibians, insects, and crustaceans profiting from beaver impoundments and their sunlight is impressive.

165 foot long Prichard Pond dam of concrete was build a century ago across Boston Brook. – Donna Bambury photo

These elaborate systems of transformation are found throughout New England now that beavers are protected. After a cold snap we’ll return and walk on the impoundments’ ice and marvel at the unseen life, active and sleeping, in the mud and rotting red maple logs below. Much is resting as are our minds in such places. Before visiting leave cell phones and pocket computers at home.


Precipitation Data* for Month of: Oct Nov Dec Jan
30 Year Normal (1981 – 2010) Inches 4.40 4.55 4.12 3.40
   2016 Central Watershed Actual 6.81 2.68 4.8** 1.0**as of Jan 3

Ipswich R. Flow Rate (S. Middleton USGS Gage) in Cubic Feet/ Second (CFS):
For Jan 5, 2017  Normal . . . 55 CFS     Current Rate . . .103 CFS
*Danvers Water Filtration Plant, Lake Street, Middleton is the source for actual precipitation data thru Nov.
** Middleton Stream Team is the source of actual precipitation data for Dec & Jan.
Normals data is from the National Climatic Data Center.
THE WATER CLOSET is provided by the Middleton Stream Team: www.middletonstreamteam.org or         <MSTMiddletonMA@gmail.com> or (978) 777-4584