The Carlisle Mosquito Online

Friday, July 14, 2006


How long will the patched dam hold?

The recent destructive flooding of the Cranberry Bog has galvanized officialdom in both Carlisle and Chelmsford. The sudden rush of water occurred when an ancient water control structure in a ponding area in the Chelmsford portion of the Cranberry Bog reservation was unable to withstand the pressure of record rainfall and unpredictable beaver activity. At the end of June, water topped and broke through the area around the structure, quickly raising the water level in the bog's downstream holding pond, until it in turn topped a bog dike and inundated a substantial section of farmer Mark Duffy's flowering cranberry plants. Duffy rushed to the breakthrough site with loads of sand and gravel and closed the openings. However, he describes his work as "a decidedly temporary fix that could not withstand a repeat buildup of water behind it."

An X marks the approximate location of the faulty dam (or weir), located in Chelmsford, upstream from the Carlisle Cranberry Bog.

(Map prepared by Hal Shneider)

The 300-acre Cranberry Bog reservation straddles the Carlisle/Chelmsford town line, with 151 acres comprising the agricultural area, dikes and portions of the holding ponds in Carlisle and 159 acres of upland, wetlands and ponding areas in Chelmsford. The ultimate source of this wetland system is Heart Pond on the northern side of Route 27 in Chelmsford.

Immediately after the problem was discovered, local officials informed their Chelmsford counterparts of the emergency situation facing the two towns, and on July 6, Carlisle Selectmen John Williams and Alan Carpenito and Chelmsford Selectman Philip Eliopolis, accompanied by Duffy and Conservation Administrator Sylvia Willard, inspected the dam (or more properly the weir) to determine exactly what had happened, what needed to be done and why a more permanent repair was deemed critical.

Need for repairs seen in 2002

Carlisle Conservation Commission (ConsCom) records indicate that Willard first notified Chelmsford's Community Development Director Andrew Sheehan that there was a potential problem at the weir site in April of 2002, and by November of 2003 Duffy had proposed a procedure whereby Chelmsford would supply a new flume/culvert; their Department of Public Works would clear the access route, and Duffy would provide the equipment and manpower needed to do the work. The Carlisle ConsCom believed they had an agreement on that overall plan until November of 2004 when Sheehan informed them that his town's Town Counsel and Town Manager were concerned about allowing someone who was not their employee to install the flume.

There the matter rested until the summer of 2005 when, at the request of ConsCom, the Carlisle Board of Selectmen wrote to the their counterparts indicating their growing unease about the condition of the flume. Sheehan replied that his engineer felt the problem was more complicated than Duffy thought, and that they were not prepared to draw down the pond in question to allow the repairs to take place. Duffy was still convinced that the crucial fix could be accomplished in two or three days and that it would not require drawing down the pond. He declared himself ready to work with anyone interested in solving the problem. On April 29 of this year Willard walked the weir site with Chelmsford Conservation Commissioner Ruth Luna, who promised to bring the problem up again at her board's next meeting. However, the threat of a breakthrough became a reality.

ConsCom chairman Roy Watson said he was hoping to see the Chelmsford Conservation Commission "move as quickly as possible to issue an emergency order, so that any work that needs to be done can be done lawfully." He added that for the long run he would like to see "this unfortunate incident" present an opportunity for the two towns to come together to work out an understanding on this and other complex matters such as water rights, "so that we avoid any future emergencies or conflicts."

Chelmsford officials

offer varied comments

A phone interview with Chelmsford Conservation Commission Chairman David McLacklan suggested that agreement is possible, but not inevitable. Noting that he and Luna had walked the dam site on Saturday morning he said he felt the matter could not wait until their scheduled July 19 meeting. He stressed that the property involved is located in Chelmsford, and said it is their responsibility to address the problem. He then outlined a three-step solution:

• Act immediately to assure that the temporary fix is made permanent.

• Undertake a timely project to replace the flume/culvert.

• Initiate a long-term project to assess the overall condition of the 200- yard weir and strengthen it as required.

He concluded by saying that he foresaw the Chelmsford Department of Public Works doing the work, "although we are aware that Duffy has a commercial interest in all this."

When we later spoke with Director Sheehan, it appeared that he was less concerned about the present condition of the weir, though he went on to emphasize that , "Our town engineer will keep an eye on it, and if he feels it is unsound, we will get a limited fix." He emphasized the town's intent to hire an eco-technical engineer with dam expertise to evaluate the situation and make recommendations for a major, long-term solution. "If it is possible, we want to make this a one-time project," he concluded.

The subject of the breakthrough was raised near the conclusion of a Monday night "working session" of the Chelmsford Board of Selectmen. Describing his visit to the site, Selectman Eliopolis noted the environmental impact the draining of the pond had had on the upstream wetland and its fauna and flora, and the serious effect on the bog farmer's operation.

Chelmsford Town Manager Bernard Lynch assured the selectmen that his office was "watching the situation," and believed that handling it might be "an involved process." He said his town engineer would evaluate the fix; the Conservation Commission would assess the environmental situation, and then he would get together with the Carlisle ConsCom "sometime in the next ten days."

There was a brief discussion of the funding involved and a basic acceptance of Chelmsford's financial responsibility, followed by a comment or two on the "financial benefits to the farmer." When Lynch noted that the farmer was willing to do work to expedite the process a board member asked, "What assurance do we have that the work will be done right," while another queried, "If we're responsible for paying for repair and then keeping it up, who is responsible for how much water is used?" Eliopolis responded, "Of course we care that whatever is done is done right, but there is an environmental issue here, and that issue is time-sensitive." Lynch then brought the discussion back to his original statement, saying, "We'll see what we can do to expedite it."

Suggestion made for long-term cooperation between towns

Carlisle Selectman John Williams was present at the Chelmsford session but, by agreement, as an auditor only. Previously he had told the Mosquito his hope was that Chelmsford would regard the situation as an emergency and act accordingly. Once the immediate issue was resolved, he would seek establishment of a two-town group to consider all the outstanding issues concerning water use and control. "This conservation land is a treasure in which both towns have a high stake," he said.

The long-term issues Williams referred to go back to the original purchase of the Bog parcel in 1986. The property , which was owned by the Lowell Cranberry Company was purchased by the two towns for open space, conservation and recreation. The water in the Cranberry Bog and two associated ponds in Carlisle comes from a system of streams, small ponds and wetlands that are located in the Chelmsford portion. The system originates in Chelmsford's Heart Pond and is guided by a series of weirs, berms, culverts and flumes. These ancient control structures allow Duffy to adjust water levels in the Bog to irrigate his sensitive plants through the growing season. But at two times of the year he needs to be able to flood the beds — in early fall, to protect them from frost, and in late fall, to float the berries for his "wet harvest."

At the time of the original purchase, Carlisle and Chelmsford applied for state Self Help Funding to cover some of the cost and form a three-party management board that would include the state. For complex political reasons at both state and local levels, Chelmsford received funding and Carlisle did not. Carlisle became proprietor of the Bog portion, inheriting its existing water rights at a cost of $1,816,540. Following two failed organic leasing arrangements, Duffy, who was already leasing the Great Brook Farm State Park dairy, applied for and was given a commercial lease by the town. It was re-written in 1995 as a 20-year lease agreement.

As for the present, Duffy finds himself unable to assess the damage done to this year's crop or the long-term impact on the complex water system that his operation depends on. However, he spent Tuesday morning at the Bog, explaining what is at stake to a delegation from Chelmsford that included McLachlan, Luna, Commissioner Caroline Hampton, Sheehan and Chelmsford's DPW Director Jim Pearson. "I am trying to remain optimistic," he said.

2006 The Carlisle Mosquito