Pond Boss Forums Thread Like Summary - Texas dam safety

We have a 45 acre community lake that is about 300 acre feet at normal pool.

Texas Commission on Environmental Quality (TCEQ) regulates dams in the state. If you break their threashold (https://www.tceq.texas.gov/assets/public/compliance/field_ops/damsafety/DamSafetyGuidance090113.pdf) they will be around to inspect your dam. We are just over the threashold of 500 acre feet at maximum (top of dam). Based on a required engineering study, our spillway is inadequte to contain a 50% maximum flood event. Now TCEQ defines a maximum flood event as 48 inches of rain in 6 hours. Think about that for a minute. Hurrican Harvey produced 60 inches, but it was over 4 days. The engineering study computed that our 40 foot spillway would need to be 170 feet wide to handle this rain event. That is wider than our dam. Since we can't create a spillway that wide, and we can't raise the dam 7 or 8 feet, our only solution is to armour the dam. This entails stripping all the vegetation from the dry side and installing engineered soil retaining mats anchored into the dam, replacing the top soil, and reseeding. All in about $120,000 project plus $6000 for engineering studies.

Just a thought, but how much over are you? My thought being, tell them to stick it, bring in some dirt, and decrease the lake size by just enough to get under their threshold. I bet it would be cheaper then having to meet their requirements, and then be subject to who knows what inspections and regulations down the road.

I remember talking to TCEQ before building our big pond. The 200 acre-feet limit was not crossed by our pond, so no issue. The 48 inches of rain measuring stick came from the Hurricane that dumped 36 inches in 12 hours way back in history. It was the event they are protecting to 150% in half the time as I recall. In my opinion, it is a very high bar indeed.

All this said, I am glad dams are being inspected. The damage water can do is incredible. The stored energy is impressive. But with the number of dams in Texas alone, they have a lot of work to do. Now, with all this said, springing a $120K bill on someone is a bit daunting, having a pathway to improvements over time seems more reasonable to me.