when do i drain my pond
last spring i bought a house in upstate new york that has a concrete-bottomed, stream-fed, all-natural pond that is around 100 feet across. there is no pump, no fountain, just a valve that can drain the pond into the stream at the other end. it is gorgeous. there were tons of tadpoles and frogs in it last summer and it was a great swimming hole for us humans. the previous owners used to drain the pond every two years in the fall. the they would shovel out all of the silt and leaves and branches that fell into it and then close up the valve and let the stream re-fill it.
my question is whether or not i should drain and clean the pond in the spring instead. my thinking was that it will be nice and clean for this summer's swimming, but as soon as the weather warmed and before i could drain it, i started noticing the tadpoles and egg sacks right away. i don't want to kill all of the wildlife in the pond, so i was wondering if those little guys would survive if they went down the drain into the stream below my pond.
should i do the cleaning now or in the fall when everything is either dead or hibernating or moved on?