Pond Boss Forums INTRO Questions & Observations spillway.. fish exit?

A few species of fish, notably Grass Carp, are drawn to moving water. These types are prone to exit ponds when water is running over the spillway.

With almost all of the species we manage for - BG, LMB, CC - adults tend to hunker down and stay put during large water movement events. So what you are likely to lose over the spillway would be numbers of small fingerlings. But except for newly stocked ponds, you have hundreds or thousands of times more small fingerlings than what are lost - so the loss is usually insignificant.

Any spillway screening attempting to halt the loss of fish MUST ensure that the spillway is not blocked during an overflow event. The result of that could mean water flowing over the entirety of the dam, with a possible dam breach resulting. Much, much worse than any loss of fish, regardless of size or numbers (lose the dam, lose them all, I figure).

Here is the partial drain pipe strainer I installed when my pond and I were young and (perhaps) foolish. Note that the back side is free of screening, letting water run full flow into the drain in an end-around long before the level rises to my emergency overflow (at least a foot higher) or, Heaven forbid, the top of the dam (about 3 feet higher). If I didn't have experience with this design NOT getting blocked (I have a very trash-free pond - no branches or sticks, very few plants) in large rain events, I would yank it out in the interest of dam safety.


WRT tea-stained water, it is probably full of tannins from trees (evergreen needles???). I don't know too much about this except, IIRC, the PH tends to be more acidic. There are a fair number of tea-stained pond owners on the forum, so stand by for eyewitness accounts. Don't panic until then - I don't recall any major problems from this condition.

P.S. Keep an eye on heybud's contemporary thread on tea-stained water over here.