Originally posted by Meadowlark:
.....
The argument about removing bottom water seems valid, but a siphon system could do that also. In addition, I would much rather spend my money on the best aeration system I could get, rather than on a bottom drain.
........ Gather the facts and make an informed decision.
howdy cw and dittos to meadowlark. when renovating my pond i had the opportunity to consider (install) additional drain systems (other than the spillway) and opted to stay w/ just the spillway which has done a bang up job for close to 40 years. the downstream ranch pond (5 ac.) has only a spillway and is reportedly over 100 yr. old. the ranch family settled the area in 1850 and built the pond around turn of century.
this is not to say that internal drain systems whether bottom type or drop tube are not useful, wise to have, and provide good control of your water, just that in my case, the spillway works well enough for my needs, and i needed/wanted to save my money for other things such as aeration. if your objectives include periodic draining for weed control, fish management or whatever else, obviously you'll need that type of control.
meadowlark, since 1981 here in Nor Cal, we've had at least 5 years of "100-yr" precip events. this last wet season (>55-inches) was one of them. the main trick for successfull spillways is to determine your worst case scenario flows (best by watershed calcs w/ good slop factor) and build accordingly.
