HLTH 6200 Week 10 Flood Mitigation Plan Example

Mill River Flood Mitigation Plan: What the County Should Do, in What Order, and How It Will Know

Student Name

Walden University

HLTH 6200: Risk Assessment, Preparedness, and Disaster Mitigation

Instructor Name

Month Day, Year

Mill River Flood Mitigation Plan: What the County Should Do, in What Order, and How It Will Know

Decision This Plan Supports

The county board must decide which flood mitigation actions to adopt in its hazard mitigation plan update and which to pursue in the next grant cycle. This plan recommends five actions, explains why and sets out how progress will be tracked. The detailed analysis behind it, the hazard profile, exposure summary, likelihood note, consequence estimate, risk matrix, mitigation menu and benefit-cost brief, is summarized here and attached as appendices. The county and its figures are a composite used for teaching.

The Risk in Brief

Riverine flooding on the Mill River ranks first among the county's hazards. A major flood is estimated to occur in about 4% of years, with a plausible range of roughly 1% to 11%, and the recent record suggests the upper half of that range is more likely. About 6,200 residents and 2,140 structures lie in the 1% annual chance floodplain. A flood like the 1996 flood of record would cause an estimated $70 million to $100 million in property damage, could cost lives on flooded roads or in a late nursing home evacuation and could shut the wastewater plant serving about 52,000 residents for one to two weeks. Federal rules require local mitigation plans to include a risk assessment and a mitigation strategy based on it (44 C.F.R. § 201.6), and this section is that assessment in summary.

Goals

The plan has three goals: protect life during floods, keep essential services running during and after floods and reduce repeated property losses in the floodplain. Each recommended action serves at least one of them, and the table below names which.

Recommended Actions

Table 1 lists the five recommended actions.

Table 1

Recommended Flood Mitigation Actions (Composite County)

Why These Actions

Action 1 addresses the least certain and most serious consequence, loss of life, at the lowest cost. Action 2 protects the most people per dollar; its benefit-cost ratio is about 1.25 at a 7% discount rate and 2.33 at 3% on the inputs in the appendix, and its benefits reach well beyond the floodplain. Action 3 removes the homes that flood most often. A national study of buyouts found that bought-out properties tend to be in more socially vulnerable areas (Mach et al., 2019), so the program must offer fair prices and relocation help to be truly voluntary. Action 4 stops new exposure from replacing what buyouts remove, at almost no public cost. Action 5 studies, rather than builds, downtown protection, because structural barriers can encourage development behind them and worsen losses when they are exceeded (Tobin, 1995).

Actions Considered and Not Recommended Now

Elevating 40 repetitive-loss homes was considered and not recommended for the next cycle, because it failed benefit-cost tests on property benefits alone. It remains an option for homeowners who decline a buyout and should be reconsidered if displacement and health benefits are valued. A downtown floodwall was not recommended for construction until the feasibility study compares it with alternatives and assesses residual risk.

How the Actions Fit Together

The five actions are designed to work together. Warning and evacuation planning protects lives in every flood, including the ones the other actions do not stop. Plant floodproofing protects the service most residents depend on. Buyouts remove the homes that flood most often, and the elevation standard keeps new exposure from taking their place. The feasibility study keeps open the option of downtown protection without committing to a structure before its risks are understood. Taken together, the actions address all three goals, and none depends on the others to be worthwhile, so a funding delay on one does not undo the rest. That independence matters in a county whose grant awards arrive on unpredictable schedules, and it lets the board fund actions as money arrives.

The plan also leaves room for actions the county cannot yet afford. If a large grant becomes available, the buyout program can be accelerated; if federal methods change to value displacement, home elevation can return to the list.

Implementation and Monitoring

The emergency management office will report progress on each action to the county board every year, using simple measures: whether the evacuation plan has been exercised, the plant project's grant status and construction progress, the number of buyout offers made and accepted, adoption of the elevation standard and completion of the feasibility study. Federal rules require local mitigation plans to be reviewed, revised and resubmitted for approval every five years (44 C.F.R. § 201.6), and federal guidance encourages jurisdictions to integrate mitigation into other plans and capital budgets between updates (Federal Emergency Management Agency, 2023). After any flood, the office will compare actual consequences with this plan's estimates and update the risk assessment.

Decisions Requested of the Board

The board is asked to adopt the five actions in Table 1 into the mitigation plan update, authorize the sewer utility to apply for a mitigation grant for the plant project, fund the warning and evacuation work and the feasibility study from the county budget, and schedule a hearing on the elevation standard. Average returns on federal mitigation spending have been estimated at about six dollars saved for every dollar spent (Multihazard Mitigation Council, 2019); the county's own numbers suggest its best actions can do at least as well.

References

Federal Emergency Management Agency. (2023). Local mitigation planning policy guide (FP 206-21-0002).

Local mitigation plans, 44 C.F.R. § 201.6 (2024).

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

Multihazard Mitigation Council. (2019). Natural hazard mitigation saves: 2019 report. National Institute of Building Sciences.

Tobin, G. A. (1995). The levee love affair: A stormy relationship? Water Resources Bulletin, 31(3), 359-367. https://doi.org/10.1111/j.1752-1688.1995.tb04025.x