Milton's Pine Tree Brook
The Brook carries 2/3rds of the run off from rain fall from the north side of the Blue Hills into the Milton neighborhood.
September 2025
Unquity Dam and Harland Street Flooding
Unquity Dam
Constructed in 1970, the dam is situated at the intersection of Unquity Road and Harland Street, often overlooked by passersby. However, this concrete structure serves a vital function during periods of substantial rainfall. The dam is essential for flood management, particularly when the Blue Hills Pine Tree Brook intersects with the overflow from Milton’s Conservation watershed during heavy precipitation events.
Pine Tree Brook
The brook begins as a modest stream at Hillside Pond and acquires strength during significant rainfall as it collects water from multiple streams descending from the Blue Hills before converging at the Unquity Dam.
Milton Conservation Watershed
The watershed borders Harland Street and during heavy rainfall, the watershed fills quickly, and overflow consistently leads to the flooding of Harland Street. Also, since the watershed backs up to the Wollaston Golf Course and surrounding homes this issue impacts both the Golf Course and the adjacent residences. Most of the homes in this area rely on septic systems. The accumulation of groundwater will ultimately pose significant challenges to the functionality of these systems.
Unquity Dam Today
Currently, the efficiency of the dam has been impaired due to a variety of issues. The entrance of the dam, which facilitates the flow of water from both the brook and the watershed into its basin, is significantly obstructed by overgrowth. This overgrowth encircles the entrance and extends around the vicinity, continuing down the berm for 100 feet or more.
The holding pond that directs water under Unquity Road is filled with dense plant growth. Also, a large amount of debris which includes broken cement and car parts including a bumper of an automobile.
Harland Street Flooding
Harland Street between Hillside Street and Unquity Road has existed for as long as town records were established and split the area watershed down the middle.
Over the years there has been an ongoing problem with Harland Street flooding requiring the street to be closed for safety reasons. Recently this complaint was directed at a beaver dam near the Unquity Dam for causing the backup of the conservation watershed resulting in the flooding on Harland Street.
Flood Control Question
Is the excessive flooding solely attributable to the beaver dam? While beavers do play a role in this issue, a more thorough examination of the area and the cause of flooding should include the significant overgrowth of vegetation especially at the entrance of the dam affecting the dam’s purpose and efficiency. [ Recently it is reported that 9 beavers were trapped and removed. ]
19-year Comparison
In May 2006, Dick Russell and I captured a video of the Unquity Dam amidst significant rainfall during the early weeks of the month. The Blue Hills Observatory recorded that a total of 10.10 inches of precipitation had accumulated by the end of the month. It was the 3rd largest amount of rainfall in a month on record at that time.
Our documentation serves as a comparative analysis of the surrounding area and the dam's performance.
The comparison of the area with the present reveals a significant contrast and a deterioration of the adjacent wetland surrounding the dam over a 19-year period. What’s is clear is that Harland Street will always flood during any significant rainfall.
SEE VIDEO BELOW
Conclusion
Irrespective of whether the beaver activity is the primary cause of the recent flooding incident on Harland Street, the excessive vegetation surrounding the dam also plays a significant role in the flooding condition.
At this time while the water level is low:
1. The beaver dam needs to be removed.
2. All vegetation in and around the dam’s entrance should be removed.
3. All debris and vegetation in the holding pond should be removed.
The Town of Milton and the DCR need to coordinate together since they share the responsibly and focus on and controlling the removal of vegetation growth.
Final word
In the published History of Milton from 1887, Albert Teele discusses the flooding of Pine Tree Brook and its adjacent regions. This area within the Town of Milton has a documented history of recurrent flooding. The pertinent inquiry is not only whether such flooding will occur again, but when will it flood again.