The Sienna Levee District: What It Protects, What It Taxes and What Harvey Showed

What is the Sienna levee district?

It is a unit of local government with its own board and its own tax, separate from the city, the county and the homeowners association. The Fort Bend County Commissioners Court created it on April 13, 1978, and its boundaries take in about 9,832 acres: roughly 8,520 acres of Sienna, 1,035 acres of Sienna Point and 277 acres of Southern Colony. Its levee and drainage system also protects Waterbrooke West and Oyster Creek Farms. It has to follow rules set by the Texas Commission on Environmental Quality, FEMA and Fort Bend County.

Its full name is the Sienna Parks & Levee Improvement District of Fort Bend County, Texas. Until 2021 it was the Sienna Plantation Levee Improvement District; the state commission approved the new name on June 15, 2021. The five directors live in the district and are appointed by the Commissioners Court rather than elected, and the district holds elections only when it asks voters to approve bonds.

How is the Sienna levee system laid out?

As two separate systems. A county drainage channel that carries water from development along McKeever Road west to the Brazos River cuts across Sienna, so the land north of it and the land south of it each have their own levee, channels and pump stations. The north system runs from State Highway 6 to that channel and includes The Woods and the Acreage Estates; the south system runs from the channel to the southern levee.

The district counts 9.7 miles of levee in the north and 10.4 miles in the south, 20.1 miles in all. When the Brazos is low, rain inside the levee drains out by gravity through outfalls. When the river rises, flood gates close to keep it out, and pumps have to lift the rain that falls inside over the levee instead.

What does the levee district tax, and what has it borrowed?

Every property in the district pays its tax on top of the school district, the county and any utility district. The rate was $0.4125 per $100 of value for 2025, made up of $0.2100 for debt service and $0.2025 for operations and maintenance, and the board adopted the same $0.4125 for 2026 at its August 26, 2026 meeting, split $0.2000 and $0.2125. The total has held at $0.4125 since at least 2023 while the debt share fell from $0.275 to $0.20.

The district's 2026 hearing notice put the average homestead at $558,199 of taxable value, with a levee district tax of $2,302.57 on it at that rate. Its notice to purchasers, compiled the same day, shows voters have authorized $249 million in levee and drainage bonds, all of it issued, and $49 million for recreational facilities, of which $45,435,000 has been issued. A seller gives that notice to a buyer, who signs it before the contract binds them or at closing.

What happened in Sienna during Hurricane Harvey?

The district's engineers, LJA Engineering, reported in February 2018 that as much as 35 inches of rain fell in the south system during the storm, and that 19 inches had fallen before the south system's river gates closed at midday on August 27, 2017. The operator's log recorded the Brazos cresting at 55.20 feet on the Richmond gauge on August 31. The report found no mechanical, structural or operational failure: the gates sealed, all 14 pumps ran, and the levees held, apart from a patch of topsoil on one inside slope that left the clay core undamaged.

Homes still took water, because more rain fell inside the levee than the system was designed to hold while the gates were shut. The report counted 73 homes with water damage across eight neighborhoods, 31 of them in Painters Bend, and judged that most had less than six inches of water above the floor. It named drainage at the back of some lots as a possible cause, and noted that the lakes and channels inside Sienna Point belong to the Sienna Point homeowners association rather than to the district.

What has the district built since Harvey?

On November 6, 2018, voters in the district authorized $139 million in bonds for levee and drainage work. The district's own summary of those projects lists four main results: pumping capacity raised from 260,000 to 1,200,000 gallons a minute, a new major outfall, 2,700,000 cubic yards of lakes and channels dug out to add half again as much storage, and 49 new flood gates.

That page was last updated in August 2023, when it said construction on the last of the projects would begin that year and that the board expected them finished in 2025. The district's current construction page, last updated in November 2022, lists a pump station and five other projects as under construction, so ask the district which are finished rather than assume every project is done.

When does the Brazos close the flood gates?

It depends on the river's height at Richmond. On June 15, 2026 the district told residents the Brazos was forecast to crest at 39.9 feet on the Richmond gauge, and that at that level the river would close the district's flood gates and could affect gravity drainage inside the levee, with pump stations tested and operators on standby. During Harvey, the operator closed the north gates at 20.27 feet and the south gates at 30.30 feet.

Heavy local rain while the gates are closed is the case the pumps exist for. Even then, the district warns, streets can pond when storm drains back up in a heavy storm, and the water recedes as the drains catch up.

Why does the levee district also run parks?

Because its powers cover parks as well as drainage, and part of its tax pays for them. In 2017 the Legislature passed House Bill 2938, which caps the district's outstanding park debt at 2% of the taxable value in the district, and at 1% for bonds voters approved before 2017 unless they approve more. The district's law, as that bill left it, requires two-thirds of voters to approve any bond backed by property taxes. The district runs Camp Sienna, sets its hours and rents out its facilities.

Does a house behind the Sienna levee need flood insurance?

The district's own resource page urges every resident to look into flood insurance and reminds them the community sits behind a levee. Whether a lender requires a policy depends on the zone the effective FEMA map gives that lot. The Texas Department of Insurance notes that most home policies leave out flood damage, and that most flood policies take 30 days to start.

Redfin shows First Street's estimate for the area: a moderate flood rating, with 2,976 properties, 46% of those modeled, expected to see severe flooding at some point in the next three decades. That estimate covers the whole area and names no house. Read it beside the lot's own map panel, the seller's disclosure notice and the house's claims history while the option period, the days after signing when a buyer can still back out for the option fee, is still open.

What does this page leave open?

Any address's FEMA zone, and whether FEMA's maps for a given panel credit the Sienna levee: this page found no FEMA or Corps of Engineers record to cite on either. It also leaves open whether every project voted in 2018 is finished, how a given street fared in a past storm, and which levee system a lot outside The Woods belongs to. The district and the lot's own paperwork are where those answers sit.