FLOOD08859

• County: Clear Creek
• Community: Georgetown
• Basin: South Platte
• Title: Flood Control Master Plan and Local Pre-Disaster Flood Mitigation Plan
• Date: 7/1/1998
• Prepared For: Georgetown
• Prepared By: Clear Creek County Office of Emergency Management
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

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Flood Control Master Plan and Local Pre-Disaster Flood Hazard Mitigation Plan . Town of Georgetown, Colorado

Concept 1 - Flood Proofing

Flood proofing is defined as "any combination of
structural or non-structural changes or adjustments
incorporated in the design, construction or
alteration of individual buildings or properties that
will reduce flood damages" (USACE, 1993). More
simply, flood proofing refers to any effort by
property owners to reduce potential flood damage
to buildings or their contents. There are three
general approaches to flood proofing:

. Raising or Moving the Building. Almost any
structurally sound building can be elevated.
Typically the least expensive type of structure
to elevate is a one story frame building
constructed over a crawl space (foundation
walls). Brick buildings or slab on grade
construction is generally the most expensive to
elevate. There is an excellent example of a
successful structure elevation project on Rose
Street at South Clear Creek. Relocation of a
building is of course the most reliable means
of flood proofing but often it is also the most
expensive and disruptive measure for owners.
Because of the historical significance of many
of the flood-prone structures, relocation of
buildings will generally not be a viable option
for structures affected by flooding in
Georgetown.

. Construction of Floodwalls or Levees
Around the Building. Floodwalls and levees
are freestanding structures located away from
the building that prevent encroachment of
floodwaters. They may completely surround the
building or protect only the low side of the
property. A sump and pump system may be

required to concentrate and remove interior
drainage and water which infiltrates either
through or beneath the levee or floodwall.

. Modifying the Building and/or Relocating
Contents to Minimize Damage. Potential
building modifications may be classified into
"dry" and "wet" flood proofing measures. Dry
flood proofing measures are designed to prevent
floodwaters from entering the interior of a
building but do not prevent their encroachment
on the exterior. Dry measures include sealing
building walls with waterproofing compounds
or impermeable sheeting, installing shields over
building openings and thick glass block
windows, and installing sewer check valves. Dry
measures are generally not recommended for
buildings constructed on crawl spaces or
basements due to a susceptibility to uplift
pressures. Wet flood proofing measures permit
a building to flood inside but attempt to insure
that there is minimal damage to the structure
and its contents. Appliances and utilities might
be permanently or temporarily moved to a
higher floor. For shallow flooding these items
might instead be elevated in place or water
proofed with plastic bags and sheeting. Another
wet flood proofmg concept is to construct a
small addition with an elevated floor. The
addition would serve as dry storage during flood
events.

In Georgetown, the line between flood proofmg
individual structures and overall flood control
schemes could become blurred because of the
proximity of private residences to the creek banks.
The presence or lack of an adequate flood wall on
any particular property unavoidably affects the

((II) MONTGOMERY WATSON . 2-3