The Issues
Reduced flood threat & protection to public & private property
“Megunticook River dams are not designed for heavy rainfall events and more such events are coming.”
—Courtney Cease
Does Montgomery Dam removal decrease flood risk?
Yes
The Montgomery Dam, like the other six dams on the Megunticook River, creates a choke point along the river increasing upstream flooding during high flows and inundating areas along the river that might otherwise store floodwaters.
Will Megunticook lake levels be affected by the Montgomery Dam removal?
No
Removing Montgomery Dam will not affect Megunticook Lake levels because East and West Dams will remain intact and are not being considered for removal.
The influence of the Montgomery Dam on flood levels extends from the dam upstream to just below the Brewster Building. It includes the Town’s Public Service Building and 15 private properties along the Montgomery Dam impoundment, which have flooded during past heavy rainfall events.
The Interfluve Megunticook River Feasibility Study has concluded that dam removal would lower water levels in the river creating a more resilient buffer to future flow conditions. Dam removal would help accommodate the nuisance flooding and moderate flooding expected to become more frequent in the coming years due to climate change.
Removal of Montgomery will add flexibility to the town’s management of Megunticook Lake levels because the impoundment of floodwaters behind Montgomery Dam will be reduced and the buildings along Main Street will be less threatened by heavy rainfall events.
What areas of downtown Camden are in Montgomery Dam’s flood zone?
(Click on image to expand.)
What is a high hazard dam? and does Camden have any?
Yes
Camden owns three high hazard dams on the Megunticook River. “High hazard” dams are characterized as risking catastrophic loss to life or property in the event of failure. East and West Dams at Megunticook Lake are high hazard dams badly in need of expensive repairs to ensure the safety of individuals and property owners. Seabright Dam at Shirttail Point has been better maintained. Funding opportunities for making necessary upgrades to the three upstream high hazard dams are only available if fish passage is enabled.
Is Rainfall Increasing in Camden?
Yes
Long term precipitation records in the Camden-Rockport area from the early 1900s to 2015 indicate the annual average precipitation has increased by 16 inches— almost a 40% increase and more annual rainfall is projected for the future (see Interfluve; Gartley & Dorsky, 2021 ).
An increase in heavy storms, which produce 2 to 4 inches of precipitation (often within a few hours), are becoming more frequent, increasing the probability of flooding (MRCAC, 2020). Climate change alters how a watershed handles precipitation. Precipitation falling for short periods of time creates flooding. More frequent and severe flooding destroys infrastructure and degrades water quality in ponds, lakes, streams, rivers, and coastal areas.
In sum, Megunticook River dams are not designed for the heavy rainfall events and more such events are coming.
When was the most recent downtown flood?
Photos of the Megunticook River Flooding Story Map show examples of flooding downtown during an October 2021 storm after the level of Megunticook Lake was dropped 23 inches below the spillway of the East Dam in preparation for the storm. The Town website has additional photos showcasing the effects of flooding on downtown buildings.