One of the public meetings held last week was to discuss plans for some flood mitigation ponds around I-10 near the Heights. Robin has some information on what is currently being proposed, plus some background info on the project if you need it.
Be sure to reference "IH-10 detention ponds" in your letter and mail it to:
TxDOT -- Director of Project Development
PO Box 1386 Houston TX 77251-1386