Incident Annexes - Dam Safety - Copy

Owned by Wayne Martin
Apr 18, 2022
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Incident Annexes – Dam Safety

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Coordination Agency

 

Harrisonburg Public Utilities

Emergency Management

Virginia Department of Conservation and Recreation (DCR)

 

Cooperating Agencies

 

Harrisonburg Police Department

Rockingham County Sheriff’s Office

 

Introduction

 

Purpose:

 

To facilitate the evacuation of downstream residents in the event of an imminent or impending dam failure.

 

Scope:

 

The Virginia Department of Conservation and Recreation provides detailed guidance to dam owners in developing an emergency action plan in the event of dam failure. City of Harrisonburg and Rockingham County are also responsible for developing compatible procedures to warn and evacuate the public in the event of dam failure.

 

Policies:

 

Dam owners will:

 

Develop an Emergency Action Plan for warning and evacuating the public in the event of dam failure.

 

Obtain an Operation and Maintenance Certificate from the Virginia Department of Conservation and Recreation; and

 

Operate and maintain the dam to assure the continued integrity of the structures.

 

The City of Harrisonburg and Rockingham County will develop compatible procedures to warn and evacuate the public in the event of dam failure.

 

 

Concept of Operations

 

General:

 

Dam owners are responsible for the proper design, construction, operation, maintenance and safety of their dams. They are also responsible for reporting abnormal conditions at the dam to the local law enforcement and Coordinator of Emergency Management and to recommend evacuation of the public below the dam if it appears necessary. Owners of dams that exceed 25 feet in height or impound more than 50 acre-feet (100 acre-feet for agricultural purposes) of water must develop and maintain an “Emergency Action Plan.” A copy must be provided to the local Director of Emergency Management, the State Department of Emergency Management, and The State Water Control Board. This “Emergency Action Plan” is required prior to issuance of an Operation and Maintenance Permit by the State Water Control Board.

 

Standards have been established for “Dam Classifications” and “Emergency Stages”. The affected public will be routinely notified of conditions at the dam during Stage 1. If conditions escalate to Stage II, Emergency Management personnel will immediately notify the public affected to be on alert for possible evacuation of the areas that would be flooded. If conditions deteriorate and overtopping or failure of a dam has occurred or is imminent, as in Stage III, the Director of Emergency Management will declare a local emergency and warn the public to evacuate the affected area. If appropriate, he will recommend that the Governor declare a state of emergency.

 

AUTHORITIES

 

In addition to those listed in the Basic Plan:

 

A. Code of Virginia, Title 62.1, Chapter 8.1, Dam Safety Act, 1982.

 

B. Virginia Soil and Water Conservation Board, Regulation VR 625-01-00, Impounding Structure Regulation, February 1, 1989.

 

EMERGENCY MANAGEMENT ACTIONS – DAM SAFETY

 

1. Normal Operations

 

a. Dam Owners

 

(1) Operate and maintain the dam to assure the continued integrity of the structure.

 

(2) Develop an Emergency Action Plan for warning and evacuating the public in the event of dam failure.

b. Government

 

Develop compatible procedures to warn and evacuate the public in the event of dam failure.

 

2. Increased Readiness

 

a. Stage I Conditions (Slowly developing)

 

(1) Alert Director of Emergency Management

(2) Alert on-duty emergency response personnel

 

b. Stage II Conditions (Rapidly developing)

 

(1) Notify Director of Emergency Management

(2) Alert on-duty emergency response personnel.

(3) Notify public of possible dam failure.

(4) Review warning and evacuation plans and procedures.

(5) Place off-duty emergency response personnel on alert.

 

3. Emergency Operations

 

a. Mobilization Phase – Late Stage II or Stage III Conditions

 

(1) Notify the Director of Emergency Management

(2) Activate EOC (staff as appropriate).

 

(3) Notify Virginia EOC, (804) 674-2400 or (800) 468-8892.

 

(4) Alert emergency response personnel to standby status.

 

(5) Begin record keeping of all incurred expenses.

 

b. Response Phase – Stage III Conditions

 

(1) Notify Director of Emergency Management

 

(2) Cooperate and assist adjoining localities with immediate evacuation of residents in expected inundation areas.

 

(3) Sound warning through use of sirens, horns, and vehicles with loudspeakers, Emergency Alert System, telephone calls, and door-to-door notification to evacuate individuals immediately out of the area or to high ground in area for later rescue.

 

(4) Call in all emergency response personnel to provide help required to protect lives and property.

 

(5) Activate EOC, if not previously accomplished.

 

(6) Follow established procedures within designated functional areas specified in this plan.

 

4. Recovery

 

a. Cooperate and assist adjoining localities providing assistance to disaster victims.

 

b. Cooperate and assist adjoining localities cleaning up debris and restoring essential services.

 

c. Cooperate and assist adjoining localities agencies tasked to implement recovery procedures.

 

d. Review emergency procedures used and revise, if necessary, to ensure lessons learned are applied in future disasters.

 

e. Determine what mitigation measures, if any, should be initiated (zoning, design of dams, etc.).

 

 

DAM CLASSIFICATIONS AND EMERGENCY STAGES

 

Dam Classifications

 

Dams that exceed 25 feet in height or impound more than 50 acre-feet --100 acre-feet for agricultural--must be classified as to the degree of hazard potential they impose should the structure fail completely.

 

Class I (High Hazard) – Probable loss of life; excessive economic loss.

 

Class II (Moderate Hazard) – Possible loss of life; appreciable economic loss.

 

Class III (Low Hazard) – No loss of life expected, minimal economic loss.

 

 

Emergency Stages

 

When abnormal conditions impact on a dam, such as flooding or minor damage to the dam, the dam owner should initiate specific actions that will result in increased readiness to respond to a potential dam failure. The following stages identify actions that may be appropriate readiness actions.

 

Stage 1 – Slowly developing conditions; five days or more may be available for response. Owner should increase frequency of observations and take appropriate readiness actions.

 

Stage II – Rapidly developing conditions; overtopping is possible. One to five days may be available for response. Increase readiness measures. Notify local Coordinator of conditions and keep him/her informed.

 

Stage III – Failure has occurred, is imminent, or already in flood condition, over-topping is probable. Only minutes may be available for response. Evacuation recommended.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Incident Annexes – Dam Safety

Attachment 1

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DIRECTORY OF DAMS REQUIRING EMERGENCY ACTION PLANS

ROCKINGHAM COUNTY

 

The following is a list of dams located in Harrisonburg/Rockingham County that require emergency action plans. The plans include the Hazard Classification, emergency contacts and Inundation Zone Maps, which include the property owners downstream of the dams that emergency responders can notify in case of an emergency.

 

Due to the size and quantity, all the emergency action plans for the dams are located in the Coordinator’s Office.

 

Dam Names:

 

  • Switzer Dam

  • Lower North River Dam 78 – Briery Branch

  • Lower North River Dam 80 – Union Springs

  • Lower North River Dam 83 – Hone Quarry

  • Shoemaker River Dam #1A - Northwoods Lake

  • Shoemaker River Dam #3B – Hogpen Lake

  • Shoemaker River Dam #4C – Slate Lick Lake

  • Massanutten Dam

  • Dry River Dam

  • Dry Run Dam

  • Newman Lake Dam