BOARDJUL048B

• Board Meeting Date: 7/20/2004
• Description: Flood Section - Outline for the Revision of the CWCB "Rules & Regulations for the Designations & Approval of Floodplains & of Storm or Floodwater Runoff Channels in Colorado"
• Board Meetings - Doc Type: Memo

~ .

STATE OF COLORADO

.. Colorado Water Conservation Board

) Department of N atnral Resources
1313 Shennan Street, Room 721
Denver, Colorado 80203
Pl1one: (303) g66-3441
FAX: [phone]
www.cwcb.state.co.us

Eli Owens
Governor

MEMORANDUM

TO:
FROM:
DATE:
SUBJECT:

Colorado Water Conservation Board Members
Lany Lang, P.E., Cbief, Flood Protection Section
July 12, 2004
Agenda Item S.b, July 20-21,2004 Board Meeting--
Outline for the revision of the CWCB ''Rules and Regulations for the
Designations and Approval of Floodplains and of Storm or Floodwater
Runoff Channels in Colorado"

Russell George
Executive Director

Rod Kuharich
CWCB Director

Dan McAuliffe
Deputy Director

.
)

Background
The CWCB conducted rulemaking during late 1987 and early 1988 in order to promulgate rules and
regulations entitled "Rules and Regulations for the Designation and Approval of Floodplains and of Storm and
Floodwater Runoff Channels in Colorado" (Floodplain Rules). They officially became effective on January 30, 1988
and have served the Board very well since that time. The CWCB received its flood protection responsibilities in 1937,
and its initial authority to review, designate and approve floodplains in 1966. The Board approved the frrst floodplain
r\~signation in Colorado during that same year. Colorado entities and their consulting engineers have understood the
need to comply with these Floodplain Rules for use on floodplain studies in order to receive Board approval.

CWCB staff, consulting engineers, floodplain managers and other interested parties have realized the need to
revise the existing Floodplain Rules due to a number of factors that have materialized since 1988. Those factors
include such things as changes in federal policies and mandates; technological advances in modeling techniques, GIS,
and digital mapping; and flood related issues such. as debris flows, erosion hazards, alluvial fan hazards, post-wildfire
. hydrology, stormwater detention, and ice jam flooding that were previously not addressed. .

Discussion
The previous agenda item (8.a - Criteria Manual Operating Principles) outlined the first step in this multiple-
step process. The Operating Principles serve as objectives and guiding language for the preparation of the Colorado
Floodplain and Stormwater Criteria Manual (Manual). The Manual will provide the references to engineering and
technical information that will work in harmony and provide significant technical support for the revised Floodplain
Rules. The Manual, in concert with the revision of the Floodplain Rules, will provide the necessary statutory authority
and guidelines to assist Colorado communities with good floodplain mapping and sound floodplain management
practices.

Staff will make a formal presentation regarding the proposed rule changes, rulemaking process, and time line
for the revision and adoption of the Floodplain Rules. The following table presents a summary of the existing and
proposed rule titles. The CWCB staff's proposal incorpOrates all of the old rules in the rulemaking process. The
process anticipates eight new rules for a total of twenty-three rules, with some of the existing rules being revised as
necessary. Attachment A provides a brief description of the existing rules and a summary ofthe new rules. .

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