Hello All, New to this forum and to pond control. Full disclosure our pond is more of a marsh but never the less I am hoping that someone can give some ideas on how to help us control water levels. I live in North Iowa 1/4 mile upstream from a Lake. Our 10 acre marsh varies in depth from a few inches to 1'-2' with another 1'-2' of mud depending on the time of the year. We have had some draught ridden springs lately and into the summer months where our marsh nearly dries up.
We have a natural levee that separates the marsh from the ditch that empties in downstream into a larger marsh and lake. There is a 15'-20' opening in the levee that empties into the ditch. I would like to build something simple such as a dam or barrier to help keep our water level up during the summer months and especially into fall for waterfowl season.
The pictures show the opening right after the county removed a beaver dam in the ditch. The water level was roughly 8" higher than what the picture shows when the dam was in. Currently the water level is another 6"8" lower than that.
Initial Ideas - I was wondering if simple pounding in some unistrut or C-channel into the ground and sliding 2'x12' into the slots would help or if there are other options out there that can be achieved by walking. We are unable to get any equipment over there to simply rebuild the levee. Again were only looking at impacting the water level 10"-16" before it breaches the "levee". Thanks!
I don't see why your idea with C channel and plank wouldn't work, as long as you could protect the sides from eroding behind the C channel in high water flows. A lot of marshes and lakes in this area use a water control structure built out of concrete with a gap to slide boards into.
Is there also water that goes out the NE corner of your picture up to the ventura marsh, or is that coming from the marsh and flowing into you?
P.S. Looks like some of your marsh is on conservation ground, may want to discuss with them before getting too far into planning anything. Outside of the normal permitting for a project of this type, they may have some additional regulations for water control in a public hunting area.
The water flows to the North down to the marsh where ours is a feeder for the large marsh. Previous owner told us it used to be completely closed off but due to erosion and animals it seems to have opened up. I was going to discuss with them but wanted to know my options. That's also why we want something we can control so that it leaves it open to any sort use for the DNR. Part of our marsh is in the conservation but this portion is completely on our property and out of any easements.
Got ya. Someone else may have a better idea, but that would be my only addition is to consider some type of wingwall/erosion control to prevent future issues. We've built wingwalls for bridge abutments out of large treated lumber for years at work, so you could do something like that fairly inexpensively and tie it in to your structure if you wanted to avoid concrete.
The only other cautionary suggestion I would make is you are likely looking at some significant permitting due to your proximity and flow into the marsh and Clear Lake. Biggest one will be the 404 permit from the Army Corp, mostly because the turnaround time on review for those varies wildly. I put your project into the state PERMT system and it says you won't need state floodplain or sovereign land permits, but that's based on the guesstimated project info I put in. The conservation folks should be able to talk you through all of the permitting, but I am guessing that your location will make it so that the permitting process is more annoying/time consuming than the actual project itself.
Maybe I will get lucky and the beavers will come back and put the dam in that spot instead of the ditch lol. Then I don't have to do any work or worry about permitting!
