FLOOD07020

• County: Statewide
• Basin: Statewide
• Title: Flood Hazard Mitigation Plan for Colorado
• Date: 2/1/1998
• Prepared For: CWCB
• Prepared By: Kistner and Associates
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

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1996 - Colorado Flood HllZllrd Mitigation Plan (4091

The Division of Water Resources, Office of the State
Engineer, published the "Manual of Rules and Regula-
tions for Filing Claims to Water and Plans and Specifi-
cations for the Construction of Dams."

All 1 ,824 dams in the state have been given high,
moderate, or low hazard ratings based on the proba-
bility of loss of life or significant properly damage
below them. The hazard classification system consid-
ers failure of the structure under "normal operating
conditions" or "failure in the dry" from structural defi-
ciencies. If a dam is found to be unsafe, the Dam
Safety Branch can restrict the storage behind it to
ensure safety.

Reservoir owners with high hazard potential dams
have been requested to prepare emergency prepared-
ness plans (EPP). These include actions to combat
dam incidentslfailures and to identify emergency offi-
cials downstream of their dams. In addition, OEM is
requesting local emergency coordinators to include the
potential for the failure of these dams in their emer-
gency evacuation plans. This project was successful
and expanded to moderate hazard dams. A model
EPP has been prepared for dam owne~s use by staff
members of the Dam Safety Branch.

Dam Ownership in Colorado

Federal ...m................................ 140
State ...................,...........'...........' 63
Local GovernmentslDistricts... 275
Privately Owned..................... 1,346
Total 1,824

(moniIrm>d and inspected by state .ngneer)

FIgure 3-2

A Dam Owne~s Safety Manual is available from the
state engineer. The manual instructs owners about the
care, inspection and maintenance of dams, both to
prolong the dam's useful life and to provide for its safe
operation. Seminars have been presented throughout
the state emphasizing the owne~s responsibility for his
or her dams. The Division of Water Resources per-
forms other flood hazard mitigation functions in the
areas listed below:

1. The division works with the U.S. Army Corps of
Engineers on Snagging and Clearing Operations
that fall under Section 208 of the Clean Water Act.
The water commissioners throughout the state
notify division engineers and the state engineer of
local flooding problems. Following that notifica-
tion, if appropriate, the corps is informed of the

FHMP.ch8pter-3.pub

Chap1ier3-5

Office of the state Engineer
Rules & Regulations for Dam Safety
2 CCR 402-1 - Effective 9/30/88

Rule 16. Emergency preparedne.. Plana (EPP)
16.A. Owners 01 Class I and Class II dams shall prepare,
maintain, and exercise Emergency Preparedness Plans
(EPP) lor immediate defensive action to prevent failure 01 the
dam. An EPP shall contain as a minimum the following:
16.A.(1) the identification of equipment, manpower, and
material available for implementation of the plan;
16.A.(2) A notification procedure for informing the local
eI11eIlleflcy agencies (e.g., emergency coordioalor or county
sheriff), and the state engineer of the problem;
16.A.(3) A dam inundation map for Class I dams;
16.A.(4) A topographic map for Class II dams showing the
streams wI1ich will be flooded; and,
16.A.(5) A procedure for warning nearby local residents il
failure of the dam is imminent.
16.8. The owner shall use the _ engineer's model EPP,
which is avaitabfe at no cost, or equivalent, for guidance in
preparing the details of the components above.
16.C. The owner shall submtt a copy of the proposed EPP to
the Colorado Office of Emergency Man~ (OEM) and
all local emergancy COOIdinatots in_ in the plan for
review. The owner shall incorporate reasonable recommen-
dations from the above, W received within 60 days 01 the
submittal.
16.D. The owner shall review and update the EPP as neces-
sary annually.

Fi9Ure 3-3

problem and the state engineer coordinates the
work with local sponsors.

2. The division reviews subdivision proposals. if the
proposal involves an area under a dam, and if
there is a clear indication of inadequate spillway
capacity to protect the subdivision, the division
will advise the local jurisdiction of the potential
effect on the hazard rating for the dam and will
recommend that the developer provide altema-
tives to assure the safety of the area below the
dam. The division will, if necessary, require that
the spillway be enlarged.

3, The division comments on dams that would p0-
tentially affect public facilities, such as utilities,
below them. Some flooding problems are related
to irrigation ditches and diversion dams. How-
ever, these facilities and their operation are not
state regulated, so the division is not involved in
addressing those kinds of floodplain manage-
ment problems. Those facilities are federally regu-
lated.

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