to be honest i have never seen something like what you are talking about as far as buying it.
Koiphen.com post something in the "construction forum" there. there is 3 to 4 active daily dealers there. they make a lot of custom fabricated stuff for folks and there ponds and lakes. "Birdman" and "Kent Wallace" and "ZP construction LLC" (user names at koiphen) do a lot of custom plastic welding jobs on stuff. and should be able to come up with something in short order for you.
if you want something locally. "DUH" i want to say look up "plastic welding" in the old paper phone book (not the internet phone books) but the old paper phone book. and there should be a couple local fabrication places. you can call and get a quote.
as far as DIY. style. get a 55 gallon drum. i want to say 30 gallon drum. might be large enough but forget the diameter of them. you can normally get them free off of craigslist.com or pay a few bucks for them. or call local "car washes" or food plants near you.
or get a ""HEAVY DUTY"" trash can. not a cheap thin plastic trash can. but heavy duty one. cheap ones get brittle and crack within a year if standing out in the sun.
anyhoots. cut the bottom out. i didn't say cut in half or cut bottom off. but cut the bottom out. and leave approx 1" or so lip around the inside. this provides strength and keeps 55 gallon drums and 30 gallon drums from warping over time.
then spend an hour or 2. either drilling a bunch of 1/2" or little larger holes. to create basicly a grate around the sides, or if you have saws. cut "slits" into the sides. drill or cut a couple holes in the top. just so water does not collect on the top of it.
to keep it from floating away or blowing away. get say 4 long bolts and put on through each side right near the bottom. then take a 4 bags of concrete (leave the concrete in the bags) and just set the bags of concrete down over the bolts sticking out. the concrete will harden over time. either by rain. or if they are underwater. it doesn't matter. the paper on the bags with also go away eventually. or say after a year. go back with a utility knife and cut any paper bag left away.
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as far what i did. i ended up using i want to say 20 bags of 80lbs of concrete. around my 24" overflow pipe. and created 2 feet wide area around around it. then i had some old 1/4" thick metal grating i concreted around the sides. then placed a flat grate over the actual hole so no one or animal could fall down into it.
reason why i went with a bigger area. is due to this 1 acre lake. there was so much debris. (moss, cat tails, willows, trees, etc...) that i needed to be sure. nothing could completely plug up. and have approx 1.5 feet above overflow pipe top. so if bottom holes did plug up. by the time it got to that high. there should be enough pressure to force moss and leaves through holes enough to let water to seep through and down the overflow pipe. ((flash flood times, like right now during this time of year and knowing this lake was also a major reason for going with a bigger area and grating around it))
do you need to do above. i doubt it. but. *shrugs* something to think about.
