OAR 690-020-0100
Hazard Rating of Dams

(1)

The Department shall assign all Dams a Hazard Rating of High, Significant, or Low.

(2)

A High Hazard Rating will be based on the Dam breach inundation analysis as described in OAR 690-020-0120 (Dam Breach Inundation Analysis) using the following criteria to determine expected loss of life:

(a)

An inundation depth of flowing Water of at least two feet over the finished floors of dwellings, other frequently occupied buildings, or road surfaces where a vehicle is likely to be present is likely to result in loss of life. The Department may also consider Water velocity in its determination of inundation depth establishing a High Hazard Rating;

(b)

An incremental increase of depth of flowing Water of one foot where recreational or other frequent use occurs downstream is likely to result in loss of life. The Department will also use Water velocity in its determination of inundation depth establishing a High Hazard Rating.

(3)

A Significant Hazard Rating will be based on the Dam breach inundation analysis as described in OAR 690-020-0120 (Dam Breach Inundation Analysis), using depth and velocity of the flowing Water at affected structures, public infrastructure, and other properties which shows likely damage to property and infrastructure but no loss of life.

(4)

Any Dam subject to regulation under these rules that is not rated as High or Significant by the Department will be rated as Low Hazard.

(5)

The Hazard Rating of a Dam shall remain in effect until the rating is revised by the Department. The Department may conduct Hazard Rating reviews and dam breach inundation analyses as evidence indicates the impacts to people, property, or infrastructure may have changed since the Hazard Rating was first set. The Dam owner will be notified of the change and have an opportunity to meet with the Department and obtain records of the Department’s analyses.

(6)

A Dam owner may request that the Department consider revision of a Hazard Rating. The owner may have an Engineer prepare and submit a Dam breach inundation analysis, in support of this request.

Source: Rule 690-020-0100 — Hazard Rating of Dams, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=690-020-0100.

690‑020‑0000
Purpose and Applicability 690‑020‑0022
Definitions 690‑020‑0024
General Department Authorities and Intergovernmental Coordination 690‑020‑0026
Fees 690‑020‑0028
Preliminary Plans and Specifications for Construction of New Dams or to Increase Dam Height 690‑020‑0035
Minimum Engineering Requirements for Final Design of New Dams or to Increase Dam Height 690‑020‑0036
Design Requirements for New Dams or to Increase Dam Height: Site Suitability and Geotechnical Evaluation 690‑020‑0037
Design Requirements for New Dams or to Increase Dam Height: Hydrology and Inflow Design Flood 690‑020‑0038
Design Requirements for New Dams or to Increase Dam Height: Embankment Dam Structures 690‑020‑0041
Design Requirements for New Dams or to Increase Dam Height: Concrete Dam Structures 690‑020‑0042
Minimum Design Requirements for New Dams or to Increase Dam Height: Spillways 690‑020‑0043
Design Requirements for New Dams or to Increase Dam Height: Penetrating Conduit(s) and Control of Flow through Conduits 690‑020‑0044
Design Requirements for New Dams or to Increase Dam Height: Instrumentation for Monitoring 690‑020‑0047
Design Requirements for New Dams or to Increase Dam Height: Geosynthetics 690‑020‑0048
Exceptions to Standard Design Requirements 690‑020‑0055
Design Requirements for New Dams or to Increase Dam Height: Design Drawings 690‑020‑0060
Design Requirements for New Dams or to Increase Dam Height: Construction Specifications 690‑020‑0065
Plan Requirements for New Dams or to Increase Dam Height: Construction Administration 690‑020‑0068
Plan Requirements for New Dams or to Increase Dam Height: Operations and Maintenance Plan 690‑020‑0070
New Dams or to Increase Dam Height: Submittals and Notifications by the Engineer of Record 690‑020‑0080
New Dams, or to Increase Dam Height, Written Approval by State Engineer 690‑020‑0100
Hazard Rating of Dams 690‑020‑0120
Dam Breach Inundation Analysis 690‑020‑0140
Modification of Dams 690‑020‑0160
Removal 690‑020‑0180
Requirement of Owners to Provide Contact and Transfer of Title Information 690‑020‑0250
Maintenance of Dams 690‑020‑0260
Inspection of Dams 690‑020‑0310
Requirement to Address Maintenance Actions Need for High or Significant Hazard Dams 690‑020‑0340
Potentially Unsafe or Unsafe Conditions 690‑020‑0400
Emergency Action Plans (EAP) 690‑020‑0420
Immediate Action to Prevent Dam Failure 690‑020‑0460
Proposed Final Order, Request for Hearing, Contested Case Process 690‑020‑0600
Civil Penalty Assessment for Dam Safety
Last Updated

Jun. 8, 2021

Rule 690-020-0100’s source at or​.us