06

• Board Meeting Date: 7/11/2007
• Description: Flood Section - Proposed Levee Administration Policy - Board Discussion
• Board Meetings - Doc Type: Memo

STATE OF COLORADO

Colorado Water Conservation Board

Department of Natural Resources
1313 She1'man Street, Room 721
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
vliv,;w.cwcb.state.co. us

MEMORANDUM

Bill Ritter, Jr.
Governor

To:

From:

Date:

Re:

Colorado Water Conservation Board Members
Kevin Houck, P.E., Flood Protection Section
June 26, 2007
Agenda Item 6 - July 11-12,2007 C\VCB Meeting
Proposed Levee Administration Policy - Board Discussion

Harris D. Sherman
Executive Director

Rod Kuharich
CWCB Director

Dan McAuliffe
CWCB Deputy Director

Intl'oduction
It has long been recognized that flood protection provided by levees can be both a benefit and a potential
problem. On one hand, levee systems have provided f100d protection to areas that would frequently be
inundated by rising waters thereby preventing property damages and personal injuries. On the other hand,
though, given enough time, levees will be ovetiopped or will fail-leading to severe flood impacts on an
unsuspecting population. Unlike a natural flood, levee failure flooding is often rapid, forceful, extremely
damaging, and occurs with little or no warning. Past experience around the country has shown that, in many
cases, flood damages occurring due to failed levees may be substantially higher than an equivalent event in
which the levee is not present.

A recent example of the potential perils of levees occuned in the City of Pueblo on May 5-6, 2007. On those
dates, a flow in Fountain Creek estimated at a 2-year retum interval forced a breach in a levee that resulted in
damages to twelve homes and three businesses in an adjacent neighborhood. Many of the residents of this
neighborhood indicated in days following the event that they were unaware of the flood threat and only one
propetiy owner held a flood insurance policy.

Backl!I'ound
Pueblo is only one example of a community that is subject to both benefits and problems associated with
levees. Many floods have been repelled by levees in various conditions throughout Colorado over the years,
but occasionally floods like that in Pueblo serve as reminders that these hydraulic structures are imperfect at
best, and often provide a false sense of security for those who live and do business behind them. Effotis are
underway by FEMA and the CWCB Flood Protection Staff to properly reflect the location of and hue
protection provided by levees on flood maps, and this has heightened the awareness of local officials and
citizens regarding the significant risk the state faces in levee-protected areas.

A further concem regarding the placement of levees is that although design and construction is often funded
by federal agencies, such as the Corps of Engineers, local govemments are often ultimately saddled with
ownership and maintenance requirements, which oftentimes exceeds the means of that govemment. As such,
levees often go unmaintained due to the absence of resources by local govemments, leading to problems with
cetiification and public perception in later years. When levees fall into disrepair due to lack of maintenance,
the following problems have been observed to occur:
, The levee no longer provides flood protection as designed

Colorado Water Conservation Board
Flood Protection. Water Supply Planning and Finance. Stream and Lake Protection
Water Supply Protection. Conservation and Drought Planning