Hanover Pond, Meriden, CT Drawn Down For Hydroelectric Technology
As it was brought to the attention of many on our Fishing CT Facebook group, Hanover Pond in Meriden, CT was drawn down. Upon investigation, Doug Thurston responded with “I am on the phone with the head of the Quinnipiac Watershed Association. DEEP has been there all day. No fish have been stranded. Everything is fine. This has been in the works for a couple years now. They found some mussel beds that were transplanted but everything else seems to be ok.”
We had reports of fish being stranded so I reached out to my sources within the DEEP and this morning received the response that I was seeking from Peter Aarrestad, Connecticut DEEP Inland Fisheries Division Director.
Peter sent me the complete report from Steve Gephart, Inland Fisheries Division, supervisor of the Diadromous Fish Restoration, and Habitat Conservation and Enhancement programs.
New England Hydro Company has received all necessary permits to construct an Archimedes Screw Generator (a new type of hydroelectric technology) at the Hanover Pond Dam. Construction began yesterday. A cofferdam will be built near the construction area where the water will enter the facility and to do that, the pond was drawn down about 6 feet. This process was reviewed, approved, and coordinated within the Department (i.e., CT DEEP). Yesterday, staff from both the Inland Fisheries and Wildlife divisions were on hand to monitor the draw down and rescue stranded animals. Of particular concern were mussels since they cannot move quickly. The draw down began at 9:00 am and by 4:00 pm the pond was drawn down to the maximum extent. As the water level lowered, three regulating riffles were exposed within the pond. That means that those riffles were acting as a mini-dam and the water level upstream of those riffles would not go down any farther, regardless of what the water at the dam did. Therefore, ponded water remained in areas of the upstream portion of the pond. The dam will remain drawn down for at least two months and possibly more as the contractor works on the cofferdam. The entire project is expected to be completed by April 1. At the latest, the pond will be restored by that date.
The loss of fish was extremely small. Most fish were able to retreat off the mudflats and into the remaining channel as the water went down. A couple hundred sea lamprey ammocoetes (larvae) died in the hot sun after wiggling out of the mud before staff could reach them. But nearly a thousand were rescued and put back into the water. Two rock bass and less than a dozen bluegills were found dead. Many bluegills, one largemouth bass, one white sucker, and two carp were returned to the water. The remaining stream of water was full of carp and other species (hard to see in the muddy water). It is likely that numerous very small fish (juvenile minnows and sunfish) have or will die after being stranded in puddles or caught up in aquatic vegetation. These were mostly less than an inch long. Only about a dozen mussels were found and all of them were successfully re-located. Considering the large expanse of the pond behind the dam, we are pleased with the very low numbers of stranded and dead fish and do not feel that it will have a lasting impact on the pond. Many fish were probably flushed downstream through the open gate and this may be a more significant factor in reducing the fish population than stranding and dying. However, the Hanover Pond Dam has a fishway that will be operated again in the spring and many of the fish that flushed downstream may re-enter the pond via the fishway. -Steve Gephart
Peter added, “After reading Steve’s summary, some anglers may ask us why we returned sea-lamprey larva to the water. The answer is that unlike the landlocked populations in the Great Lakes that are causing significant damage to salmonids and other sportfish, the sea lampreys in CT are all natural anadromous populations that have been here for thousands of years. They are not harming fish populations in freshwater. I pointed this out because we are often asked about this.”
Now going by this report, I would say they seemed to have all of their ducks in a row this go around. When doing something of this nature you have to expect some losses but must try to keep them to a minimal. In my eyes, they took all of the necessary steps to assure the safety of the fishery. I can also attest that many fish have conjugated up stream, down stream and in the channel as I have already received reports from anglers. If you have any further questions feel free to email me at [email protected] and I will look into getting answers for valid questions that have not been answered with this report.