Pond Boss Forums Thread Like Summary - Ravine Dam Lake Construction Central Illinois

Hello everyone, I'm brand new to the forum, so any and all advice is perfect. I bought some property (central Illinois) and it has 1 large ravine and a smaller ravine that met at the low end where I'm going to build a dam. I've already had it logged out, all left over trees, brush and everything else has been cleaned up and either burned or completely removed. I plan on doing the damn build myself,I have great soil plenty of clay very close to the dam. I've talked to the Army Corp and the state everything is fine as long as I don't exceed a 25ft. tall dam. I plan to go as high as 25ft, with my fretboard at 22ft. The point of where the dam is being constructed width is a pinch point so from side to side is around 100ft long(dam length). Do I need to run the core deep into both sides(they are all clay) and go as high as my water level(22ft.) Or can I core into both sides let's say 4ft. and build up from that point to kinda lock it into the sides as well? I plan on a 2:1 slope on both sides of the dam. Next question, seeming it's clay everywhere do I need to strip out all(or as much as I can) of the topsoil in the pond area from dam to the shallow end? If not does it all need to be compacted or can I just leave it all along and let it fill?

Please save yourself a lot of cost and a whole lot of 'WishIWuddas..' and get a consultation and a site visit by a reputable pond builder. Not a dirt mover, a pond builder. A 25 foot dam has unique challenges in its design and construction and I would never ever want you to have this be your first experience with building a pond with a dam. You didn't mention how comfortable you are in building ponds or dams.

This forum is riddled with folks who paid dirt movers who have found just about every way possible to be sure that the pond looked good long enough for them to cash the check and leave the site only to have the pond be a 'leaker' forever afterwards. Fixing it later is WAY more expensive then doing it right the first time. So many people were assured that there was plenty of 'good clay' on site only to find that there are a lot of kinds of clay and it is the way the clay is applied that matters the most. Even one small vein of stone or gravel is all it takes. You need a lot of planning, prep work, test holes, watershed calculations, plans for overflow, siphons, etc etc.

There are too many people aching about how things ended up after hours of work and lots of money and I hate to see you end up in their ranks and with a much larger scale project that didn't turn out as you had envisioned.

But, the good news is welcome to a great forum filled with helpful resources and good people. One of the IL pondmeisters can share with you their experience and also can recommend reputable and SUCCESSFUL pond builders in your area.

Sage words of wisdom from a guy in the same area as you that wishes he'd found this site BEFORE he built his pond....

1 - DO go to the NRCS office and get their recommendations. And specific to the whistle/culvert size, I recommend something between 150% and 200% bigger than what they say. I used their recommended '100 year rain' sizing and almost lost my pond 5-6 times in a 4 year period before I paid to have the culvert dug BACK out and replaced with one 50% bigger.

2 - PUT IN A BOTTOM DRAIN/SIPHON - ideally with a valve and/or a hookup that could be used - this is my #1 regret. It's a bit pricey to put in but it's IMPOSSIBLE to add later without some serious work/draining your pond/etc. A bottom drain gives you a way to adjust your water level easily, getting rid of the water that's essentially no use to your fish anyway. And having a way to quickly draw down your pond is something I've wished I could do dozens of times since I built the pond. It also might decrease your insurance rates if you have a house or buildings close to the pond as your local fire dept could use it as a water source - depending on how you build it.

3 - READ READ READ. There's a ton of knowledge here. I bet I picked up 15-20 REALLY good tips in my first few weeks on here that I'd have paid good money to have prior to building my pond. Stocking advice, structure construction, etc all is a TON easier to plan for now vs after the pond is full.

4 - if your pond area is anything like mine you probably have ag runoff coming in. If that's the case plan for a riparian area/grassy entry/spot to catch runoff/sediment pond/etc. I sort of lucked into this one, I didn't really plan for that but 2 of the 3 spots I get significant runoff into I was lucky enough to have very shallow, so now I have vegetation there strategically placed to capture as much of the silt (and corresponding phosphorus) as I can. You'll thank your lucky stars on this one when you have less algae than anyone else.

Learn from our mistakes - I've made a ton. And as far as getting a pond builder's help depending on where you are in Central IL I might be able to steer you to some local words of wisdom.

I would remove as much topsoil as possible. Topsoil has many uses and can even be sold to recoup some of the building cost. As dale mentioned one does not know what type of soil is actually under the topsoil so removing the topsoil will reveal the subsoil and hints to where likely spots to check if the pond leaks.

If it were my pond I would at least get all the pond bottom down to clay and drive over it several times with a sheepsfoot roller as a form of leak insurance. 8 times or pass with the roller by the book. A leaky pond will be a long term headache for you especially if you try to fix the leak. Quote from Rainman: "all the pond basin needs to be well compacted during construction. Don't fall into the myth that a 50,000 pound dozer will compact soils, as there is less PSI of pressure than a typical home refrigerator." "Spending a little on insurance in the way of proper bulding will save huge dollars if the pond leaks and needs to be redone. I had a dirt pusher build a dam and the original build was $3800. The bills to "fix" all his mistakes topped $32,000."


With all those surrounding trees that each year will contribute lots of leaf organic matter it is better if you remove topsoil to add as much overall depth as possible. I've seen ponds in wooded areas that gain 1ft of dead leaf matter each year. This not only fills in the pond but reduces water quality and increases chances of fish kill both in summer and winter. Do it right the first time even if you have to make the pond somewhat smaller; you won't regret it.