PU545 Unit 3 Flood Mitigation Proposal Example

Buy the Bend Instead of Rebuilding It: A Unit 3 Mitigation Proposal Asking Composite Brennock County to Acquire Forty-Two Repeatedly Flooded Homes at Mill Creek, With the Benefit-Cost Arithmetic for a Floodwall and Elevation Beside It

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Purdue University Global

PU545: Disaster Management

Unit 3 Mitigation Proposal

[Instructor Name]

[Date]

Brennock County, the Mill Creek bend and all cost figures are composite; the mitigation methods, the benefit-cost approach and the research cited are real.

Request

Brennock County requests 6.4 million dollars in hazard mitigation assistance, with a 1.6 million dollar local match from the county capital fund, to acquire and demolish 42 residential properties at the Mill Creek bend, relocate the households with their consent, and record a permanent open space restriction on the land.

The Problem in Four Dates

Water entered the first floor of these 42 homes in 2007, 2013, 2019 and 2024. Nineteen of the 42 are on the national repetitive loss list. Claims paid across the four events total 7.9 million dollars, which is more than the acquisition this proposal asks for, and the figure excludes uninsured losses, the two bridge closures and the three weeks of emergency sheltering in 2024. Average first-floor elevation is 2.6 feet below the mapped base flood elevation. The bend is a meander with the creek on three sides, so water arrives from two directions and recedes slowly.

Option One: Floodwall and Pump Station

A wall tall enough to hold the 2024 crest with a foot of freeboard runs 2,900 feet and requires a pump station to handle interior drainage. Construction is estimated at 11.2 million dollars, with annual maintenance of 95,000 dollars and a pump station the county would own for fifty years. It protects every structure behind it, which is the strongest argument for it. Against it: the wall protects 42 homes at a capital cost of 267,000 dollars each, it transfers some water to the opposite bank where 14 further homes sit, and a residual risk remains, since any wall can be overtopped and the consequences when it is are worse than if no wall existed. Benefit-cost ratio at the county's figures is 0.74, below the threshold for assistance.

Option Two: Elevation in Place

Raising each house above the base flood elevation costs between 95,000 and 180,000 dollars depending on foundation type, averaging 128,000, for a total of 5.4 million dollars. Benefits are real: elevated homes in this bend would have stayed dry in all four events, and the benefit-cost ratio is 1.31, which qualifies. Two objections keep it from being recommended. The households remain in a bend that loses road access in any event above 24 feet, so emergency services still cannot reach them and they still need evacuation. And elevation does nothing about the 11 outbuildings, the two septic systems that failed in 2019, or the creek's continued erosion of the bank. Elevation keeps the water out of the house. It does not get the ambulance in.

Option Three: Voluntary Acquisition and Open Space

Acquisition at pre-flood fair market value, demolition, and relocation assistance come to 8.0 million dollars for all 42 properties, or 190,000 each. Benefits counted over fifty years include avoided structural losses, avoided contents losses, avoided emergency response and sheltering costs, avoided road closures, and the floodplain storage the open space restores, which lowers crest height slightly for the 14 homes on the opposite bank. The benefit-cost ratio is 1.68, the highest of the three. Residual risk after the project is zero for these 42 households, because the hazard is not reduced but vacated.

What the Evidence Says About Buyouts

Voluntary acquisition is the mitigation measure with the clearest permanent effect and the hardest implementation. A national study of buyouts found that participation is uneven, that programs run for years, and that the properties acquired are concentrated in places that have flooded repeatedly, which describes this bend exactly (Mach et al., 2019). Household behavior is the limiting factor rather than the engineering: willingness to act on flood risk depends on what people believe about the next flood and on their attachment to the place, not only on the dollar offer (Bubeck et al., 2012). The proposal therefore budgets 18 months for acquisition and accepts that some owners will decline.

Implementation and Schedule

1. Months 1 to 3: notify all 42 owners in writing, hold two public meetings, and record declinations without pressure.

2. Months 2 to 8: appraisals at pre-flood value, title work, and relocation counseling through the county housing office.

3. Months 6 to 16: closings in the order owners are ready, demolition within 60 days of each closing.

4. Months 12 to 20: grade the lots, plant the bend, record the open space restriction, and transfer maintenance to county parks at 14,000 dollars a year.

5. Month 24: report the number of properties acquired, the number declined, and the revised floodplain storage to the state.

What Happens to the Owners Who Decline

The proposal assumes six to ten households will decline, and it says what the county will do about them rather than leaving the figure in a footnote. Those homes stay in the floodplain, keep their flood insurance obligations, and remain on the evacuation list. The county will not maintain the private road to a standard that implies permanence, and it will offer elevation assistance from a second funding source if any owner later asks. Saying this in the proposal protects the county from a charge of coercion and is also honest about the outcome: a voluntary program produces a partial result, and a proposal promising total clearance of the bend would be promising something the law does not allow.

Why This Is Mitigation and Not Response

Mitigation is work done before anything happens, and the test of it is whether the next event is smaller rather than whether the response to it is faster. The floodwall and the elevations would both leave the county responding at the bend in 2030. Acquisition ends the county's exposure there permanently, which is why the proposal ranks it first despite being the most expensive per home, and why the planning process that produced this analysis treated the recurring loss record as the starting point rather than the hazard map alone (Perry & Lindell, 2003).

References

Bubeck, P., Botzen, W. J. W., & Aerts, J. C. J. H. (2012). A review of risk perceptions and other factors that influence flood mitigation behavior. Risk Analysis, 32(9), 1481-1495. https://doi.org/10.1111/j.1539-6924.2011.01783.x

Mach, K. J., Kraan, C. M., Siders, A. R., Johnston, E. A., & Field, C. B. (2019). Managed retreat through voluntary buyouts of flood-prone properties. Science Advances, 5(10), eaax8995. https://doi.org/10.1126/sciadv.aax8995

Perry, R. W., & Lindell, M. K. (2003). Preparedness for emergency response: Guidelines for the emergency planning process. Disasters, 27(4), 336-350. https://doi.org/10.1111/j.0361-3666.2003.00237.x