Potomac Waterfront Flood Mitigation Study - City of Alexandria

Refinement of Mitigation Measures
specific criterion. This was to verify that the final alternatives that would be analyzed in further
detail were not being subjectively selected by the process. The final score and overall rank for
each flood mitigation alternative are listed in Table 2-3.
Alternative
ID
Total
Score
Table 2-3: Flood Mitigation Measure Final Rankings
Ranking Alternative Definition
S1 500 1 Build an engineered structure to act as a barrier between the
Potomac River and Alexandria.
S2 499 2 Build a pedestrian boardwalk that would also be a floodwall
structure.
PP5 473 3 Acquire properties experiencing frequent flooding.
ES5 466 4 Provide sandbags or other flood deterrents for residents and
businesses.
S3 439 5 Increase the inlet and road elevation to prevent overflow from
nuisance flooding events.
PP6 435 6 Elevate structures.
PP2 396 7 Provide dry floodproofing with impermeable membranes and
watertight shields to prevent floodwaters from entering
buildings.
PR2 389 8 Improve the City’s floodplain and zoning ordinances.
PP3 379 9 Relocate internal supplies, products/goods, and utilities above
the flooding depth.
S6 376 10 Improve flapgate operation at outflow points.
PP1 348 11 Provide wet floodproofing to make uninhabited portions of
structures resistant to flood damage.
PR1 339 12 Add backflow preventers in homes to prevent stormwater (and
sewer) backups.
ES1 334 13 Isolate service so that only the buildings affected by flooding
would have service turned off.
PP4 324 14 Relocate external electrical boxes.
ES4 323 15 Improve the City’s emergency response.
EA3 309 16 Inform business and residents about reimbursement for
damages other than just exterior building damages.
Do Nothing 309 16 Do nothing.
ES2 303 18 Improve/enhance existing business identification system for
returning to impacted area.
ES3 303 18 Implement system to provide text messages, announcements,
and/or phone messages regarding the status of the flooding.
ES6 299 20 Provide improved cleanup program.
EA1 294 21 Provide education to area media outlets about what is causing
the flooding, how to avoid flooded areas, and what in
Alexandria would remain open and accessible.
EA2 279 22 Create maps, provide signs, and help erect barriers (that would
be only as large as needed) to show visitors and residents how
to navigate the streets and show what businesses and parking
areas remain open.
S7 254 23 Add sump pumps.
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