Water Closet for 11-15-13 Beaver Building Time Again
Middleton is again in the midst of a building boom. Roads from roads are being added. Houses arise along them. These activities are obvious in our daily rounds. Plans for more are “on the drawing boards” as old timers still sometimes say. Wooden boards are gone; plans are now done on computer screens by engineers in front with mysterious things behind called software programs. One of Middleton’s new developments includes a significant bridge across Boston Brook off Essex Street. Two massive 40-foot wide box culverts, arched at the top, are in place. A busy road climbing to undeveloped uplands crosses the brook over them. Just up and down stream from the bridge, dams are being raised by other contractors who work in family units. Their projects aren’t obvious unless you notice the changes in water levels in wetlands and floodplains of our brooks and river, higher waters that are due to impoundments above beaver dams, not rain. It hasn’t really rained to speak of here for a long time. We’ve had only seven inches in the last three months; the 30 year average for the period is about 14. The beavers are making new dams and patching up old ones in preparation for winter’s thick ice. When you are down Market Basket way, on route 114, turn instead into Logbridge Road and continue by the Vo-Tech school toward Danvers Fish and Game Club. You’ll soon come upon the Stream Team’s park where from 1672 to 1972 Logbridge connected the east side of the Ipswich River to the west. In colonial times it was a cart path from Salem to Andover. Stop and sit at one of the picnic tables and look down on a less than two month old dam crossing between the ruins of the old bridge’s stone abutments. Stream Teamers have been visiting weekly and marveling at the well made structure which is slightly bowed up river for strength. Larger branches have been carefully laid side by side on the down river side with smaller branches and bushes tucked into spaces between them. Mud carried by paws has been plastered against them on the upriver side. The water level is now three feet higher on one side than on the other. In September when started it looked like a scraggly raft of loose branches. These were knitted together and somehow tied to the bottom. Our visits miss the actual work. Some of us vow to get up earlier or go later at dawn and dusk, but somehow never do. Later visits with lights would probably disrupt the night shifts. Now as winter approaches there is fine new dam bank to bank. It is only three feet high and 50 feet long yet it backs the water up 2500 feet to another dam built across the river by a different family. The Logbridge dam is the easiest one to visit by car. The rest, and there are many in Middleton, require hikes in to the construction sites. They are well worth the effort. Older dams are being added to and again made semi-watertight. Additional new dams are being built. Drive up North Liberty to Prichards Pond, a third-mile long swelling in Boston Brook due to an early 20th century manmade dam, 160 long and 7 feet high. During the great Mothers Day Flood of 2006, a 30 by 2 foot section near the south end of the concrete dam was torn asunder and pushed down stream.
The beavers had a couple lodges on the dam’s pond. That fall they built a 30 plus foot arc of sticks and mud above the breach that raised the water up to where it was before the flood. During springs and summers beavers don’t worry much about their dams. There is no need when there is no thick ice limiting access water for swimming underneath. A month ago Prichard’s Pond was two feet lower than it is today. Now you’ll find its surface up where it ought to be thanks to a new section of dam beavers again built as high as the main manmade parts at its ends. We needn’t visit to confirm this. Prichard Pond’s beavers do this every fall and have since 2006. Even if the floating ice extends down three feet there will still be liquid water underneath to move around in. The most impressive beaver works visited this fall are those below Stearns Pond in Harold Parker State Park, North Andover. Stearns Pond is the result of a Civilian Conservation Corps dam built in the 1930s. Its overflow is to a stream that runs a mile southeast to Emerson Bog in Middleton. In the last 14 years beavers have built four dams across the stream. The impoundments there have drowned over a hundred acres of red maple swamp. One great dam near where Middleton, North Reading, and North Andover join has gone from one foot high, 30-foot long, in 14 years, to a 300-foot long structure six times as high. The impoundment backs water up for half-a-mile. Most of the red maples drowned have long fallen. In their place is a shallow lake where wildlife thrive. One winter while hiking on its ice, we came upon a flock of bluebirds flitting among doomed swamp dogwood bushes. On that same very cold jaunt we admired the teeth marks of moose vertically scarring the gray bark of dying red maples. The waist high scars were apparently made by moose wading on the bottom before the ice. All these many impoundments around the county, work of the last 20 years, are places of great diversity. As with the Logbridge dam we who like beaver dams and the habitats they produce plan to return at day’s first and last lights when the birds are most active and the dam builders out and about. One old Stream Teamer, since his first sighting of beaver signs here in 1995, has kept a map of their dams and lodges in Middleton. At last count there are marks for over 40 known dams. If you’d like a copy let the Stream Team know. It isn’t GPS accurate or always up to date. Middleton has almost 10,000 acres, many acres still well away from our network of asphalt paths. Better still, obtain one of our stream maps and look for signs on your own, or even better explore without maps and see what you can find. You’ll be rewarded at these sites with more than just dams, lodges and dead red maples. The death of trees has let light in upon the retained waters. Above and below beaver dams lush herbaceous plants and bushes bloom in their seasons. The best part of these wildlife gardens is that they are different every year. There are two extensive building industries in town, one dry the other wet. The wet is carried on without money or permits. The upland industry results in large houses and chemically doused lawns without grazing animals or playing children. The more modest abodes of sticks and mud are surrounded by useful water gardens. The grazers and players there are rarely seen by us. Same town, separate worlds.