Pond Boss
Posted By: Jim N. Proposed pond in floodplain - 08/26/20 06:46 PM
I recently purchased a property where there is a low spot with an occasional flow of water. Looking at the flood plain maps this area is in the flood plain recognized by FEMA. See map attached. I would like to build a spillway type dam in the lower portion and dig out and remove trees to create a 7-8 acre lake.

I am trying to do my research and as I understand it I will need to work first with the Army Corp of Engineers (ACoE) in my region to see if a lake can be built within the waterway. Perhaps a flood control or erosion control lake can be built? My local County offical indicated to check with the ACoE if a permit is needed. If one is required then a seperate County permit would have to be issued as well to cover any construction.

As I understand it a plan submitted to the ACoE can be quite difficult and possibly very expensive generate. I am looking for feedback if this is crazy to even consider or is there a potential possibility to get this accomplished? What potential hurdles will I run into and what are the next steps?

BTW - There are two smaller tanks on the property. The larger one is a mess. Trees are growing through the dam and it's more swamp then lake at the moment. Regardless of what I can do in the lower portion of the property this upper pond will have to be addressed/filled in and rehabbed.

Attached picture property.JPG
Posted By: Dave Davidson1 Re: Proposed pond in floodplain - 08/27/20 09:02 AM
I would check with a reputable dam builder about regulations. The words waterway, flood/erosion control seem to generate a lot of governmental interest. Lusk has a Facebook program on Wednesday(I think) nights. You might ask the question there.
Posted By: Jim N. Re: Proposed pond in floodplain - 09/04/20 11:24 PM
Yes I checked with one and he seemed to indicate permits likely would not be required. I realize he wants to build! I just want to make sure I don't run afoul later on which could be quite expensive. I'm producing a package to submit to the ACoE's now. Once that is submitted I hope to hear back within 45 days if it's a thumbs up or down.
Posted By: esshup Re: Proposed pond in floodplain - 09/05/20 02:33 AM
I wouldn't send anything to the ACoE's unless it was absolutely mandatory. Like opening Pandora's box.
Posted By: Jim N. Re: Proposed pond in floodplain - 10/26/20 04:04 AM
Sent a package to the ACOE based on a conversation with the local NRCS contact in the county. The ACOE replied back that no permit was required and I have that in writing now. The NRCS indicated that they would not recommend to build in that area and they would not fund any construction there. Well I really didn't expect them to build my pond anyway so no loss. I am talking with a couple builders now and getting quotes. The one guy believes the site is well setup for a large pond and it's really about how much dirt we have to move. The location has clay like soil and a couple smaller ponds are holding water even in dry periods .
Posted By: Snipe Re: Proposed pond in floodplain - 10/26/20 04:49 AM
You got darn lucky...I wish I would have seen this earlier but the only time you HAVE to contact ACoE is if you are interfering with a riverbank or floodplain directly adjacent to or directly upstream of..a federal (Classified Navigable) stream/waterway.
ACoE could still potentially come back on that because there are several permit types issued..Been through this fight.
Again, I'd say you are lucky.. might want to go buy a lottery ticket also.
Posted By: Jim N. Re: Proposed pond in floodplain - 11/03/20 08:34 PM
I hear you. The only reason for interacting with them is the NRCC rep thought this was a portion of some system they may be interested in. Essentially they said yes it floods from time to time but not a tributary of anything they are worried about. I'll go buy that lottery ticket!

I'm working on getting quotes now and will see how expensive this might get.
Posted By: BranClanFarm Re: Proposed pond in floodplain - 11/22/20 12:26 AM
That is good to hear. I am closing on some property soon in Grimes county, and have the same thing going on. I was originally going to enlarge the pond that is not in the flood plain, but now I am thinking of putting the pond in the floodway so I don't take up and "good" non flood plain real estate. I was wondering this exact thing about permitting if I messed with the flood plain area. Sounds like I should be just fine.

Attached picture satellite view flood zone.jpg
Posted By: Dave Davidson1 Re: Proposed pond in floodplain - 11/22/20 10:03 AM
Texas can get narrow minded about impeding flood plains that go into the streams then rivers and then to lakes that cities have built for drinking water. Here, it is best to not get caught doing it. I have a spring fed creek that I decide to dam up about 25 years ago. I worked my butt off building a dam. I showed a pic to Mike Otto who grinned and said good luck. Then we got some booming rains that proved to me that I had no idea how to stop flowing water. Next was a 4 year drought that dried up the shallow aquifer. The springs that had run forever have never rebuilt themselves and I now have a seasonal creek.
Posted By: FishinRod Re: Proposed pond in floodplain - 11/22/20 09:04 PM
Jim and BranClan,

Good luck on your projects. Getting past the COE is only the first step.

As Dave points out, "impeding flood plains" almost certainly puts you on the radar of a multitude of regulatory agencies.

I don't know the rules in Texas, but here is the Kansas list of activities in floodplains that draw scrutiny and potential fines.

(c) “Development” means any man-made change to real estate, including, but not limited
to:
(1) buildings or other structures;
(2) mining;
(3) dredging;
(4) filling;
(5) grading;
(6) paving;
(7) excavation or drilling; or
(8) storage of equipment or materials.


After you get past the floodplain management regulations, you run into the levee regulations.

Basically, it is normally easy to get approval to grade your gravel driveway in the floodplain - but do not stockpile topsoil and gravel. You can probably get approval to dig a Texas "tank" style pond in the floodplain, but if you raise an embankment for the pond more than a foot above grade, then you trigger a slew of levee regulations. If you are impeding the floodplain, near homes or a city, then the review could get expensive very quickly.

My advice, get all of your approvals FIRST during the design phase of your project before you start spending money moving any dirt.
Posted By: Jim N. Re: Proposed pond in floodplain - 12/31/20 05:42 PM
Just an update. I've got soil sampling completed and looks like we have a good fit with heavy clay throughout the build site. Below it's very plastic as well. Should hold water well but waiting for the official report. The only change is the spillway system will bypass around the pond and take advantage of a very wide and flat grassy area for bypassing the pond. I think were good to go and just need good weather and the rest of my master plan to get completed. The master plan involves a house and shop as well so that is taking up a majority of the planning time so far.
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