Another problem is Houston is in Harris County and the land to the north and the west that contributes to flooding the Buffalo Bayou route to the ocean are in different counties and multiple different municipalities. This would require the different government entities to cooperate on a solution that limits each others development. The state government is fairly dysfunctional in this area and raising money to fund anything by raising taxes does not look likely for the forseeable future - their solution so far to fund public schools is to cut taxes which force them to unfund them a little bit more each year, leading to ubiquitous fund raisers by parents for their local schools.