FLOOD04301

• County: Delta
• County: La Plata
• County: Gunnison
• Community: Pitkin, Delta, La Plata, Gunnison, & Routt County
• Basin: Western Slope
• Title: Appendix to 1993 Colorado Flood Report
• Date: 6/1/1994
• Prepared By: CWCB
• Floodplain - Doc Type: Flood Documentation Report

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LOCAL GOVERNMENTS SHOULD PREPARE FOR SPRING RUNOFF

With a high snowpack in much of Colorado's high country, there is a lot of talk about the threat
of flooding in communities downstream of that snow. FEMA was contacted as early as January
with requests for assistance. Colorado's Office of Emergency Management and the Water
Conservation Board are beginning to work with some of the communities that may face snowmelt
flooding to prepare for the possibility of flood problems. Some local governments are making
their own plans. All of this activity raises the question, "What should we be doing in my town?"

In very simplified fonn, here are the kinds of things that local officials and those who help them
should be perfonning if they anticipate the possibility of a high spring runoff.

I. Gather baseline data
2. Assess the general problem
3. Co-ordinate with the appropriate agencies
4. Assess specific potential problems
5. Organize a local response team
6. Infonn the public
7. Refine your response plan as you get more data

Gather Baseline Data

The USDA Soil Conservation Service collects and disseminates snowpack infonnation for its
survey throughout the mountains of Colorado. The infonnation is compared to a 20-year average
to facilitate prediction. Local officials should learn what the readings are for the basin(s) that
drain through their community. Local officials should also familiarize themselves with their
floodplain maps. Whether they are Flood Insurance Rate Maps or other maps and whether they
are approximate or detailed maps, they will predict geographic areas of potential concern. The
proft]es that accompany detailed maps will predict potential flood depths.

Assess the General Problem

Examining the available snowpack data and the floodplain maps should pennit local officials to
make a preliminary assessment of the risk faced by their community. A snowpack of greater
than 150% of average indicates a potential problem. A floodplain map that shows several
buildings in the I DO-year floodplain or a flood profile that shows bridges that would be
overtopped by a 100-year flood indicate a potential problem. In a preliminary sense the
snowpack infonnation and the floodplain infonnation can be combined to detennine whether the
community has reason for further concern.

Co-ordinate With the Appropriate Agencies

There are three state agencies with which local governments that are concerned about the risk
of snowmelt flooding should co-ordinate their efforts. These agencies are the Department of
Local Affairs' Office of Emergency (OEM), the Division of Water Resources (State Engineer)
and the Colorado Water Conservation Board (CWCB). OEM is responsible for emergency