How to Save on Flood Mitigation

Since 2000, flood-mitigation spending in Harris County has topped $3 billion dollars. That’s through the end of the third quarter this year. Right of way (ROW) acquisition and construction represent the two largest components of that cost. ROW by itself consumed more than $1 billion and cost almost as much as construction. With saner building codes and floodplain regulations, we could have saved much of that for additional projects.

At the end of Q1, I made a Freedom of Information Act (FOIA) request to Harris County Flood Control District (HCFCD) for more than 20 years of financial records. I wanted to see how much we spent, where we spent it and what we spent it on. You can find the results on the funding page of this web site. I recently requested updated numbers through the end of the third quarter. While I haven’t finished analyzing the latest numbers yet, one thing leaped out at me immediately.

ROW Costs Virtually as Much as Construction

I knew the acquisition of property for large detention basins or channel expansions was expensive. However…

I had no idea that right-of-way acquisition cost HCFCD almost as much as construction of mitigation projects.

As you can see from the chart below, 36 percent of all HCFCD spending on mitigation projects goes toward the acquisition of Rights of Way (ROW). Forty percent goes toward construction. And 24 percent goes toward “all other.”

Based on data provided by HCFCD in response to a FOIA Request. Covers all capital improvement spending from 1/1/2000 through end of third quarter 2021.

What are Right-of-Way Costs?

Right-of-way costs represent the purchase of land on which HCFCD builds its projects. HCFCD can’t just build projects on someone else’s land. They need to acquire the land first. ROW acquisition can take years. Often people don’t want to leave homes and neighborhoods they may have grown up in…despite the flood risk.

Even with willing sellers, HCFCD must appraise the property, locate the owner, negotiate a price, close the sale, and demolish the property before doing anything.

Four and a half years after Harvey, about half of the Forest Cove Townhomes on Marina Drive remain standing but uninhabitable. They must all be torn down before HCFCD can revert the property to green space.

Buyouts of some properties elsewhere have taken a decade or longer.

Factors Affecting Percentages

Several factors affect the ROW percentage above.

When Projects Started

Projects that started recently may show a higher percentage of ROW costs, simply because construction may not have even started yet. Conversely, some projects that started in the 1990’s did not even have any ROW costs included in these numbers because they fell outside the period (2000 to 2021) of investigation.

Population Density

Population density also affects ROW acquisition costs. It’s more expensive to purchase land after development than before. For example, inner city land with apartments and high rises costs more than rural land. See below.

Brays Bayou at South Main near Texas Medical Center shows difficulty of expanding channels in developed areas. Photo May, 2021.
Type and Location of Density

Areas where people have built right next to the edge of bayous increase the cost of mitigation. They also increase the time it takes to complete projects. HCFCD had to buy out whole subdivisions along Halls Bayou in order to build the two giant detention ponds at US59 and Parker. The buyouts took three to five times longer than construction.

Note heaviest concentration of damage inside Beltway 8

Frontier Program

Counterbalancing that, HCFCD sometimes purchases large tracts of undeveloped land in rural areas as part of its Frontier Program. That enables HCFCD to build large regional flood mitigation projects in optimal locations at a lower cost per acre without the cost or delays of buyouts. HCFCD later resells detention pond capacity to developers to make its money back. The emphasis in the Frontier Program is on preventing flooding, rather than fixing it. That requires upfront investment. But it’s also a more humane approach because people aren’t flooding multiple times before HCFCD can acquire matching grants and take action.

Opportunity for Savings

If we could get developers to leave larger easements next to creeks and bayous, it could reduce ROW-acquisition costs in the long run. It could also enhance safety for residents and the reputation of developers. Wider ROW could be marketed as greenbelts and jogging trails – salable amenities. And people are usually willing to pay a premium for flood-safe homes. So this isn’t asking developers to be totally altruistic.

Would we save a billion dollars? No.

If you look at flood damage maps of Harris County, most flooding in the last 20 years has happened inside Beltway 8. We still need to fix much of that.

But going forward, the opportunity exists to reduce that 36% gradually to something more reasonable.

How much depends on whether you can make people in surrounding counties see the floods in their future if they don’t take action now. Flooding is already a significant issue in large parts of Montgomery and Liberty Counties. Perhaps that will motivate upstream interests to cooperate with downstream interests.

Posted by Bob Rehak on 12/7/2021 with grateful thanks to all the men and woman who fought at Pearl Harbor

1561 Days since Hurricane Harvey