Pond Boss Forums POND CONSTRUCTION Building a dam New Pond Construction in Watkins Glen, NY

Update Part 2
I have attached a picture showing the inlet (left), beach (center) and spillway (right). The drainage ditch runs from left to right just above the bottom of the picture.

Water comes into the pond from 2 drainage ditches. The total watershed is around 33 acres. I have rerouted about 28 acres of drainage to a ditch that runs along one side of the pond. From previous rain events, I know this ditch easily handles the 2 million gallons per day one might get. This ditch enters the pond area about 9” above the full pond level and drops to about 2’ below the dam. This enables me to tap into the ditch as it comes in and later use it as the outlet for the spillway. To do this in a more controlled manner I built a combination concrete weir and gate.
The #5rebar reinforced concrete structure has slots for a board weir and board gate. It should handle the large volumes from a 100yr event, ensuring that the majority of the water never enters the pond but stays in the ditch.

The main channel sides are beveled slightly which should help with ice expansion. Don’t know yet if it will survive winter but it shouldn’t have more than 5-6” of ice at any time. We were in a moderate drought and did not get any runoff since the first week of June so I didn’t get to try it out until just before the arctic blast came through last week and froze everything in place (went from 35 to -5 in 8 hours).

My pond is still 4-1/2’ below full but I suppose there is enough water frozen in place out there to fill it. There is a 12” conduit embedded into the concrete structure after the gate, taking the inlet water under a driveway. After the conduit, the water flows through 30’ of stone and 30’ of flooded sedge meadow widening as it goes before transversing stone and gravel covered geo-textile and dropping into the pond. The sedge meadow hopefully will catch coarser sediment and leaves from the hickory grove that lines the drainage ditch. The gate also limits the leaves coming in from the ditch and encourages them to go downstream. The gate will limit water coming in and reduce the likelihood of flooding and needing the emergency spillway.

I have included pictures of the dry weir & gate, it in operation, and after the sudden cool down. We only got to run this for a few hours before everything froze.