OAR 690-020-0140
Modification of Dams

(1)

No person shall make Modifications to a Dam unless the State Engineer has reviewed all required documents as described in this section and has approved those documents as indicated in written communication with the Engineer of Record or Dam owner.

(2)

The following Dam Modifications require State Engineer approval of plans:

(a)

Changes to or near the Spillway that may affect Spillway capacity or ability to pass flows safely;

(b)

Placing, replacing, or relining any Conduit within the Dam;

(c)

Removal or alteration of the Conduit control structure;

(d)

Installation of a new Valve on the downstream side of the low level Conduit;

(e)

Correction of damage where that damage has impacted the safe functioning of the Dam;

(f)

Any activity where 10 percent or more of the fill material in the Dam is disturbed; or

(g)

Any other change to the Dam that results in a Modification as defined in OAR 690-020-0022 (Definitions)(28).

(3)

Dam Modification plans shall include all details of the area of the Dam being modified. Specific modification plan requirements include, but are not limited to:

(a)

For major Spillway damage or alteration, plans need to address passage of the required Inflow Design Flood based on the Hazard Rating of the Dam, with the same criteria as required for new Dams in OAR 690-020-0037 (Design Requirements for New Dams or to Increase Dam Height: Hydrology and Inflow Design Flood);

(b)

For stabilization of slope movement, plans require slope stability analysis and appropriate corrective measures;

(c)

For replacement of Conduits or installation of a Valve on the downstream side of a Dam, plans require an analysis of internal erosion potential;

(d)

For internal erosion, plans must address construction of a filter zone; and

(e)

Items required by the State Engineer pursuant to subsection (4).

(4)

The Dam owner shall provide sufficient notice to the Department to allow for adequate time for discussion of the proposed Modifications and the necessary design requirements.

(5)

The State Engineer will determine the design and submittal requirements. Submittal requirements and Department reviews may be expedited in the event of emergency or unanticipated weather-related situations.

(6)

Water is not to be stored in the reservoir during modification. The Engineer of Record may propose maintaining some Water in storage during Dam Modification or modifying Dam Height if it is demonstrated that it can be done in a manner that protects life, property, and infrastructure. The Department will review submitted materials for the proposed construction actions. The Department may consider the scope of the project, including how the proposed construction actions will maintain safe Water levels through the duration of construction.

Source: Rule 690-020-0140 — Modification of Dams, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=690-020-0140.

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 690-020-0140’s source at or​.us