FLOOD04156

• County: Statewide
• Basin: Statewide
• Title: Flood Hazard Mitigation Plan for Colorado 409
• Date: 2/1/1998
• Prepared For: State of Colorado
• Prepared By: CWCB
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

199B. Colorado Flood Hazard Mitigation Plan (4091

The Division of Water Resources, Office of the Slate
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 property 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 req uested 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 owner's use by staff
members of the Dam Safety Branch.

Dam Ownership in Colorado

Federal...................................... 140
State ............................................ 63
Local Govemments/Districts ... 275
Privately Owned..................... 1,346
Total 1,824

(monitored and inspacted by state engneer)

Rgute 3-2

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A Dam OWner's Safety Manual is available from the
stale engineer. The manual instructs owners about the ,
care, inspection and maintenance of dams, both to I
prolong the dam's useful life and to provide for its safe !
operation. Seminars have been presented throughout
the state emphasizing the owner'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 I
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 I;
local flooding problems. Following that notifica-
tion, if appropriate, the corps is informed of the I

FHMP-chap1eT-3.pub

Chapter 3 . 5

Office of the State Engineer
Rules & Regulations for Dam Safety
2 CCR 402-1 - Effective 9130/88

Rule 16. Emergency Preparedness Plans (EPP)
16.A. OWners of Class I and Class II dams shall prepare,
maintain, and exercise Emergency Preparedness Plans
(EPP) for immediate defensive action to prevent failure of the
dam. An EPP shall contain as a minimum the following:
16.A.(1) the idenlilication of equipment, manpower, and
_I available for implementation of the plan:
16.A.(2) A notiflClllion procedure for informing the local
emergency agencies (e.g., emergency coordinator 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 which wiD be flooded; and,
16.A.(5) A procedure for warning nearby local residents if
failure of the dam is imminent.
16.8. The owner shall use the state engineer's model EPP,
which is available at no cost, or equivalent, for guidance in
preparing the details of the components above.
16.C. The owner shall submit a copy of the proposed EPP to
the C_ Office of Emergency Management (OEM) and
all local emergency coordinators involved in the plan for
review. The ovmer shan incorporate reasonable recommen.
dations from the above, If receiVed within eo days of the
submittal.
16.D. The owner shall review and update the EPP as neces-
sary annually.

Figure 3-3

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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 alterna-
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 po-
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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