I looked at a house on Conroe last weekend. I shall use this information as leverage when negotiating price.
Ask if the house got flooded when the SJRA didn't open the gates during the hurricane?
Gates were open the entire time. At one point, releasing near 80K cfs. That will happen when the lake's watershed get 18" of rain in short order.
With that said, if the house didn't flood during Harvey, you're probably ok.
If the gators don't work for leverage, use the lowering of the lake during the spring and during hurricane season. There's a possibility that if you have a dock, it could be dry if seasonal rains are below what they're expecting. I believe they lower the lake 1-foot during the spring and 2-feet during hurricane season.