BOARD01548

• Board Meeting Date: 1/25/2005
• Description: Proposed Revisions to the Rules and Regulations for Dam Safety and Dam Construction
• Board Meetings - Doc Type: Memo

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STATE OF COLORADO

. OFFICE OF THE STATE ENGINEER
Division of Water Resources
Department of Natural Resources

1313 Sherman Street, Room 818
Denver, Colorado 80203
Phone [phone]
FAX [phone]

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W#\N.water.state.co. us

Bill Owens
Governor
Russell George
Executive Director

MEMORANDUM

Hal D. Simpson, RE.
State Engineer

To:

Colorado Water Conservation Board Members

Jack Byers, Deputy State Engin~~
January 18, 2005 /r'"

From:

Date:

Re:

Agenda Item 5, January 25-26, 2005, Board Meeting-
Proposed Revisions to the Rules and Regulations for Dam Safety and Dam
Construction

I.

Dam Safety Pro!!ram Overview

The mission of Colorado's Dam Safety Program is to prevent loss of life and property damage,
determine the safe storage level and protect the state's water supplies, from the failure of dams,
within the resources available. In addition the program provides a level of general safety and security
ofthe critical infrastructure and response to emergency situations. The Dam Safety Program is
based on Title 37 Article 87 C.R.S. (2004), the key provisions consist of: I) The review and
approval ofthe plans, specifications and construction of new dams and modifications to existing
dams; and 2) The determination of safe water storage levels through evaluation and inspection of
existing dams. There are about 3000 dams in Colorado, about 1900 are greater than lOft in height
and store more than 100 acre-feet of water. The Dam Safety Program is focused on reducing the risk
of the loss of life and reducing the potential for significant property damage due to the failure of
dams.

There were 48 dam incidents requiring emergency action between 1990 and 2003, 23 incidents
involving High Hazard (Class 1) dams, dams where loss ofIife is expected in the event of failure
(fortunately no lives were lost), 10 incidents involving Significant Hazard (Class II) dams, dams
where significant property damage is expected in the event of failure, and 15 incidents involving
Low Hazard (Class III) dams, dams where no damage to structures and public facilities is expected
in the event of failure. Fortunately no lives were lost during the above incidents, During the same
period 57 new dams were constructed in Colorado. There are currently 8 new dams under
construction and 37 plans for modification ofrepair of existing dams where approved in 2004.
The most recent comprehensive study of dam failures, UNICIV Revort-Analvsis of Embankment
Dam Incidents, Universitv of South Wales 1998, identified 48% of the known failures were due to
overtopping or failure of spillway/gate structures. The current spillway requirements in the Dam
Safety and Dam Construction Rules are based on national and worldwide standards as well as court
decisions. SpecificaIIy the Barr v Game Fish and Parks Commission. 497 P .2d 340 (Colo.App.
1972), which held that the defendant was negligent for failing to design the spillway to pass the