1,074 bodies hold flood authority in the San Jacinto basin. The 27 percent figure making the case against that has no source.

A long-running Harris County flood watchdog counts 1,074 separate bodies with flood authority in the San Jacinto River basin. Harris County is one of them, and it is the one writing most of the checks.

Why it matters

Every flood dollar this county argues about, the 2018 bond, the Harvey grants, the 200 drainage projects on a map with no money behind them, is spent inside a basin where no single body can say yes. Water runs downhill across county lines. Authority does not.

That is the useful part of Bob Rehak’s October 5 post at Reduce Flooding, which argues for regional flood authorities on the strength of that fragmentation.

By the numbers

11 counties, in whole or in part, make up the San Jacinto flood planning region. That figure appears both in Rehak’s post and in the San Jacinto Regional Flood Planning Group’s own published FAQ.
83 municipalities and 980 other entities with flood-related authority in the basin, per Rehak’s reading of the amended 2023 San Jacinto Regional Flood Plan.
1,074 bodies in total, by our addition of those three figures.
The region is the second most populous of the state’s flood planning regions despite being the second smallest by area, per the planning group.
5.2 million Texans and 1.66 million buildings sit in identified 100-year or 500-year flood hazard areas statewide, per the 2024 State Flood Plan as cited by Rehak.
27 percent of people in the basin live or work in a floodplain, against about 10 percent nationally, per Rehak. He does not cite a source for either figure.

What the coverage buried

The number in the headline is the number without a citation. The post is labeled analysis, it is open about what it argues for, and most of its figures are tied to a named state document. The 27 percent and the 10 percent benchmark are not. A reader can check that in a minute: open the post and look for where either comes from.

That matters because 27 percent is the whole case. If more than one in four people in this basin live or work in a floodplain at nearly three times the national rate, the argument makes itself. The claim may well be right. It is not yet checkable, and the basin’s own planning documents are where it would have to be confirmed.

The other side

The objection comes from both directions at once, which is usually a sign it is serious.

From the right: a new regional body with taxing power is the last thing a Harris County homeowner needs in a year when the county raised the rate 3-2 and set the flood control rate at exactly the voter-approval line. Another layer does not drain anything.

From the small towns upstream: an authority weighted by population would be run by Harris County, and the communities taking water from upstream development would be outvoted by the place doing the developing. Local control over drainage is how a neighborhood gets heard at all.

Both are fair. Fragmentation and a new taxing body are not the only two options. Binding coordination on specific projects, with published cost shares, would test whether the problem is really authority or really money.

What to watch

Whether the October 15 Commissioners Court meeting carries any flood item. The October 6 meeting was cancelled.
Whether the next regional flood plan cycle publishes a population-at-risk figure that can be checked against the 27 percent.
Which of the 200 mapped drainage projects the Flood Control District says has funding attached.

Bottom line

The fragmentation is real and documented: 11 counties and roughly a thousand other bodies holding a piece of the authority over one watershed. The 27 percent is the part that still needs a source. Harris County keeps paying for flood work either way, which is the reason to get the number right before anyone builds an agency on top of it.

Sources

Editorial