Although the date of origin for the Colburn Street Dam is unknown, it is certainly over 100 years old. The dam is located within the Historic Mother Brook adjacent to the land now owned by the Town known as Condon Park. The first mill in Dedham was built on this site in the 1600's and over the centuries leading up to the early 1900's, the mill was used to mill corn and generate wool and finish cotton pieces. The Colburn Street Dam created the upstream impoundment now known as "Mill Pond". Over the past few decades, Mill Pond has been revitalized by local community groups and has become a favorite spot to visit along Mother Brook.
Over the past 100 plus years the Colburn Street Dam has been in existence, very little maintenance has been undertaken. The Town conducted a Phase 1 & Phase 2 Dam Assessment of the dam and determined that although the dam was not in danger of breaching that it did require some rehabilitation in order to extend its useful life.
METHOD OF REHABILITATION
The method of rehabilitation to occur, as recommended by the Town's consultant Dewberry, will consist of the following:
- Removal of sediment accumulated against the upstream face of the dam for the application of a 4" to 5" thick layer of shotcrete. This layer of shotcrete will provide structural reinforcement to that face and will be able to fill any voids in the face uncovered when the sediment is removed. It will also provide a water proofing layer on the face which will substantially reduce seepage through the dam structure.
- Grout pack and point the stones on the downstream face of the dam. This will eliminate the voids between the stones and reinforce their structural integrity.
- Replace the existing wooden stop log system with an aluminum stop log system that will provide improved operation and maintenance while eliminating the current leakage that occurs there.
- Placement of riprap at the downstream face of the dam and extending approximately 30 feet downstream. This will protect the downstream area behind the dam from scour during high flow situations. In addition, the riprap will extend far enough to dissipate the energy from all but the highest flows encountered at the dam.
At the Spring Town Meeting held in May of 2016, Town meeting voted to approve the bonding of $755,000 for the design and construction of the Colburn Street Dam. The design was awarded and completed by Dewberry at a cost of $99,980. The construction contract was awarded to T. Ford Company, Inc. with construction cost of $485,548.00. Resident Engineering will be conducted by Dewberry at a cost estimate of $135,000.00.
The project started on August 7, 2017 and is anticipated to be completed by the end of November 2017.