4.12. SR 06-16-2014 City of
Elk=' Request for Action
River
To Item Number
Mayor and City Council 4.12
Agenda Section Meeting Date Prepared by
General Business June 16, 2014 Suzanne Fischer,Director, CODD
Item Description Reviewed by
Emergency Action Plan for Lake Orono Dam Cal Portner, City Administrator
Reviewed by
Action Requested
Approve,by motion,the updated Emergency Action Plan for the Lake Orono Dam.
Background/Discussion
Elk River Municipal Utilities (ERMU) has updated the Emergency Action Plan (EAP) for the Lake
Orono Dam per the request of the Minnesota Department Natural Resources and the League of
Minnesota Cities. The plan had not been updated since the 1980's.
ERMU and city staff discussed and reviewed rough draft. Comments and updates were then forwarded
to Ayers Associates to complete the final draft.
The updated EAP for the Lake Orono Dam was approved by the Elk River Municipal Utilities
Commission at their June 10, 2104, meeting.
Since the dam is owned by the city, this EAP also requires City Council approval. An approved plan is
required prior to July 1 for insurance renewal.
Financial Impact
N/A
Attachments
■ Emergency Action Plan for the Lake Orono Dam
P a w E A E U s r
Template Updated 4/14 INIM UREI
EMERGENCY ACTION PLAN
Elk River Dam
Elk River, Minnesota
r
Prepared for:
Elk River Municipal Utilities
June 2014
42
EMERGENCY ACTION PLAN
ELK RIVER DAM, AKA ORONO DAM
LOCATED ON THE ELK RIVER IN THE CITY OF ELK RIVER, MN
NATIONAL INVENTORY OF DAMS ID: MN-00516
COUNTY: SHERBURNE COUNTY
OWNER: CITY OF ELK RIVER
OWNER REPRESENTATIVE: CAL PORTNER
OFFICE: (763) 635-1001
CELL: (763) 438-2743
ADDITIONAL CONTACT: MARK THOMPSON
CELL: (763) 238-3465
FAX: (763) 441-8099
DAM OPERATOR: ELK RIVER MUNICIPAL UTILITIES, TROY ADAMS
OFFICE: (763) 441-2020
ADDITIONAL CONTACT: TECHNICAL SERVICES SUPT., WADE LOVELETTE
CELL: (612) 670-2096
OWNER MAILING ADDRESS: CAL PORTNER
CITY OF ELK RIVER
13065 ORONO PARKWAY
ELK RIVER, MN 55330-0430
Plan prepared by: Jen Jacobson Environmental Scientist Ayres Associates
Name Title Company
Signature Date
AVMS
ASSOCIATES
3433 Oakwood Hills Parkway
Eau Claire, WI 54701-7698
715.834.3161 • Fax: 715.831.7500
www.AyresAssociates.com
Ayres Associates Project No.26-0771.00
43
TABLE OF CONTENTS
Page No.
I. Notification Flowchart........................................................................................................ 1
Table 1. Notification List for Emergency Levels 1 and 2.................................................... 2
11. Statement of Purpose ....................................................................................................... 4
111. Project Description............................................................................................................ 4
Figure1. Dam Location..................................................................................................... 5
Figure 2. Plans for the Elk River Dam ............................................................................... 6
IV. Emergency Detection, Evaluation, and Classification........................................................ 7
Table 2. Guidance for Determining the Emergency Level.................................................. 8
V. General Responsibilities under the Plan............................................................................ 9
A. Dam Owner Responsibilities............................................................................................. 9
B. Responsibility for Notification.......................................................................................... 10
C. Responsibility for Evacuation ......................................................................................... 10
D. Responsibility for Duration, Security, Termination, and Follow-Up.................................. 10
E. EAP Coordinator Responsibility...................................................................................... 11
VI. Preparedness.................................................................................................................. 11
A. Surveillance.................................................................................................................... 11
B. Response During Periods of Darkness........................................................................... 12
C. Access to the Site........................................................................................................... 12
D. Response During Weekends and Holidays .................................................................... 12
E. Response During Periods of Adverse Weather............................................................... 12
F. Alternative Systems of Communication........................................................................... 13
G. Emergency Supplies and Information............................................................................. 13
1. Stockpiling Materials and Equipment...................................................................... 13
2. Coordination of Information..................................................................................... 13
3. Other Site-Specific Actions ..................................................................................... 13
VI1. Inundation Maps.............................................................................................................. 13
Figure3. Inundation Map ................................................................................................ 15
VI11. Appendices................................................................................................................. 16
i
44
I. Notification Flowchart
Orang — Emergency Levels 1 , 2, and 3
Red — Emergency Levels 1 and 2 only
Purple — Emergency Level 1 only
Observer 1. Sherburne County Sheriff's Communications Division
911 or 763-765-3595
1. Residents 1. Elk River Police Department
See Table 1 Bradley R. Rolfe
L 763-635-1260
1/2. Elk River Municipal Utilities 2. Elk River Fire Department
Troy Adams T. John Cunningham
763-441-2020 763-635-1100
After Hours Dispatch
888-606-4660 3. Sherburne County Sheriff Non-
Emergency Services Division
763-765-3595
1. National Weather Service
Diane Cooper
952-361-6671 4. Wright County Sheriff's Department
763-682-1162
2. DNR State Dam Safety Engineer
Jason Boyle 5. Wright County
651-259-5715 763-682-3900
3. Technical Services Superintendent 6. Hennepin County
Wade Lovelette 612-348-3000
763-670-2096
5. Elk River Public Works
Suzanne Fischer
4. City of Elk River 763-635-1120
Calvin Portner
763-635-1001
June 6, 2014 Page 1
45
Emergency Level 3 merely requires notification of Elk River Municipal Utilities.
Emergency Levels 1 and 2 require notification of a broad range of departments,
officials, and Emergency Level 1 also requires evacuation of downstream residents.
Parties on the notification flowchart shall be contacted by phone or, if necessary, in
person. Radio communication is available between the power plant, the Street
Department, and the sheriff's office. When notifying the parties for whom they are
responsible, each caller should inform them of the emergency level that has been
activated, explain the exact conditions, and—if applicable—refer the party to the EAP
for their responsibilities. Downstream residents who are notified should be informed
that an emergency situation now exists, and that evacuation is necessary.
Table 1. Notification List for Emergency Levels 1 and 2
Caller To Be Notified Phone
1. Sherburne County Sheriff's Communications 911
Division (911 Dispatch)
Observer
2. Elk River Municipal Utilities 763-441-2020 or
888-606-4660
1. Elk River Police Department 763-635-1260
2. Elk River Fire Department 763-635-1100
Sherburne County 3. Sherburne County Non-Emergency Division 763-765-3595
Sheriff's
Communications
Division (911 4. Wright County Sheriff's Department 763-682-1162
Dispatch)
5. Wright County 763-682-3900
6. Hennepin County 612-348-3000
1. National Weather Service 952-361-6671
Elk River Municipal
Utilities
2. DNR State Dam Safety Engineer 651-259-5715
June 6, 2014 Page 2
46
3. Technical Services Superintendent 612-670-2096
4. City of Elk River 763-635-1001
5. Elk River Public Works 763-635-1120
1801 Main Street
1705 Main Street
1703 Main Street
1433 Main Street
1431 Main Street
1331 Main Street
1319 Main Street
1313 Main Street
1305 Main Street
1237 Main Street
1227 Main Street
Elk River Police 1221 Main Street
Department 1215 Main Street
1209 Main Street
1149 Nile Lane
1141 Nile Lane
231 Nile Place
223 Nile Place
229 Norfolk Street
223 Norfolk Street
217 Norfolk Street
209 Norfolk Street
201 Norfolk Street
1033 Manor Place
1023 Manor Place
June 6, 2014 Page 3
47
II. Statement of Purpose
The purpose of this Emergency Action Plan (EAP) is to provide the owner/operator of
the Elk River Dam with a clear plan of action when any dam emergency arises, with the
intent of safeguarding the lives and reducing damage to the property of the citizens of
Sherburne County living along the Elk River. An emergency is identified as any
condition which:
• develops unexpectedly;
• endangers the structural integrity of the dam; and
• could result in the dam's failure producing downstream flooding, requiring
immediate action.
This EAP provides information about the dam and contact information for all parties
involved in responding to or affected by an emergency at the dam. The EAP outlines
what actions are required in the event of an emergency.
III. Project Description
The Elk River Dam is located in Section 33 of Township 33 North, Range 26 West,
within the City of Elk River, Sherburne County, Minnesota. The dam impounds the Elk
River, forming Orono Lake, a recreational waterbody. The Main Street Bridge is located
immediately downstream. The Mississippi River is located approximately one mile
downstream. A location map is presented in Figure 1 on the following page.
The Elk River Dam is a high hazard concrete gravity dam with a structural height of 15
feet, and a structural length of 207 feet. The dam consists of the following components,
from left to right looking downstream: a concrete flood wall, an earthen embankment
fuse plug, an abandoned powerhouse (foundation only), a fixed crest overflow spillway,
a concrete tainter gate spillway with three steel gates, a fixed crest overflow spillway,
and an earthen embankment fuse plug. A plan and section of the dam are presented in
Figure 2 on page six.
The contributing watershed area at the dam is 640 square miles. At a normal elevation
of 871 .3 mean sea level (msl) the pool is 281 acres, with a maximum depth of 18 feet.
The normal storage is 1 ,600 acre-feet, and the maximum capacity is 2,800 acre-feet.
The maximum discharge is 10,000 cubic feet per second.
The nearest upstream dam is Eagle Lake Dam on a tributary to the Elk River,
approximately 10 miles from the Elk River Dam. The nearest downstream dam is the
Coon Rapids Dam on the Mississippi River, approximately 17 miles from the Elk River
Dam.
June 6, 2014 Page 4
48
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IV. Emergency Detection, Evaluation, and Classification
Dam tenders perform a general inspection of the Elk River Dam on a daily basis, and a
detailed inspection at least once a year using the inspection form in the Inspection,
Operation, and Maintenance Plan. Every five years inspection of the dam is required of
a professional engineer proficient in dam structure and safety. During these inspections
situations that could lead to emergency conditions are closely evaluated. Comparison
of data from one inspection to another can potentially reveal progression of issues.
There are three emergency levels that correspond with the severity of a condition, as
well as the degree of threat to life and/or property. These levels are detailed in steps
below which outline the general procedures to be taken during an emergency situation.
Step 1: Event Detection
• Detect event
• Assess situation
Step 2: Emergency Level Determination
• Table 2 on the following page provides guidance on determining the emergency
level. The emergency levels are as follows:
• Level 1 — Urgent; dam failure appears to be imminent or in progress
• Level 2 — Potential dam failure situation; rapidly developing
• Level 3 — Non-failure condition; slowly developing; high water
• It may be necessary to consult with other parties prior to determining an
emergency level. This may include the General Manager of Elk River Municipal
Utilities, the DNR's State Dam Safety Engineer, or a private consulting engineer.
Note: Timely determination of the appropriate emergency level is critical to
maximize the available response time.
Step 3: Notification and Communication
• Level 1 —Activate Level 1 Emergency Notification Flowchart
• Level 2 —Activate Level 2 Emergency Notification Flowchart
• Level 3 —Activate Level 3 Emergency Notification Flowchart
Step 4: Expected Actions
• Level 1 — Save people; evacuate
• Level 2 — Save dam; protective actions; potential evacuation warning
• Level 3 — Monitor situation
Step 5: Termination and Follow-up
June 6, 2014 Page 7
51
Table 2. Guidance for Determining the Emergency Level
Event Situation Emergency
Level
Spring run-off or major storm event 3
High Flow Spillway flow that threatens to flood people downstream 2
Spillway flow that is flooding people downstream 1
Fuse Plug Reservoir level is 1 foot below either of the fuse plugs 2
Overtopping Water from the reservoir is flowing over either of the fuse plugs 1
New seepage areas in or near the dam 3
Seepage New seepage areas with cloudy discharge 2
Seepage with cloudy discharge; increasing flow rate 1
Observation of new sinkhole in reservoir area or on embankment 2
Sinkholes
Rapidly enlarging sinkhole 1
Structural New cracks in the structure greater than '/4-inch wide without seepage 3
Cracking Cracks in the structure with seepage 2
Structural component deformation 1
Structural Displacement of dam 1
Failure
Gate failure or malfunction 1
Embankment Visual movement/slippage of the embankment slope component 2
Movement Sudden or rapidly proceeding slides of the embankment slopes 1
Verified bomb threat that, if carried out, could result in damage to the 2
dam
Security Threat
Detonated bomb that has resulted in damage to the dam or 1
appurtenances
Unauthorized operation of the dam 3
Damage to dam or appurtenance with no impacts to the functioning of 3
the dam
Sabotage or Modification to the dam or appurtenances that could adversely impact 2
Vandalism the functioning of the dam
Damage to dam or appurtenances that has resulted in seepage flow 2
L mage to dam or appurtenances that has resulted in uncontrolled 1
ter release
June 6, 2014 Page 8
52
V. General Responsibilities under the Plan
A. Dam Owner Responsibilities
The City of Elk River owns the Elk River Dam and it is operated by Elk River Municipal
Utilities. Familiarity with federal guidelines for the inspection and evaluation of dams will
assist dam owners in maintaining safe dams.
Understanding and recognition of potentially dangerous conditions may prevent dam
failure. Elk River Municipal Utilities shall advise the dam tenders of the importance of
the EAP, and shall keep dam tenders trained in use of the EAP, and in detection of
situations that trigger use of the EAP.
Operators' duties under the EAP are to: detect situations that require the activation of
one of the Emergency Levels; determine the appropriate Emergency Level (conferring
with the owner's representative as necessary); activate the notification flowchart as
necessary; and provide assistance and monitoring as required by the dam owner's
representative. When activating the notification flowchart, the operators shall at a
minimum inform the party which Emergency Level has been activated for the Elk River
Dam, the reason for activation (refer to Table 2), and to refer to the EAP for details on
their duties. For example:
Dispatch, Emergency Level 1 has been activated for the Elk River Dam. This is
due to failure of one of the tainter gates. Please refer to the EAP for details on
the notifications you must immediately initiate.
Only after the notification flowchart has been activated should dam operation actions be
taken. Actions should preferably be done under guidance of the DNR State Dam Safety
Engineer in order to ensure that measures are both necessary and safe.
The City of Elk River is the official representative for EAP situations. Elk River will
obtain and provide advice concerning predetermined remedial action to delay,
moderate, or alleviate the severity of the emergency condition. The duties (which may
be delegated to the Elk River Police and Fire Departments) of the dam owner and
operator are to:
• contact parties for whom they are responsible in the notification flowchart;
• provide information to the DNR on existing severity and rate of change of the
problem;
• request assistance from the DNR (personnel for expert supervision and
monitoring, equipment, materials) as necessary;
• ensure that operations and repairs directed by the DNR are carried out;
• and to act independently to implement emergency operations and repairs in the
event communications with the DNR are disrupted or immediate action is
required, including deciding the urgency of correction, carrying out appropriate
portions of the emergency operations and repairs, obtaining needed personnel,
equipment, and materials, and providing for 24-hour monitoring of the situation.
June 6, 2014 Page 9
53
It is also the responsibility of Elk River Municipal Utilities to coordinate with leadership at
the City of Elk River to ensure full awareness by the dam owner.
B. Responsibility for Notification
In a Level 1 or Level 2 Emergency situation it is the responsibility of the observer to
activate the flowchart by contacting the Sherburne County Sheriff's Communications
Division and Elk River Municipal Utilities. In a Level 3 Emergency situation, the
observer is responsible for notifying only Elk River Municipal Utilities.
When contacted during a Level 1 or Level 2 Emergency situation, the Sherburne County
Sheriff's Communications Division is responsible for contacting the Elk River Police
Department, the Elk River Fire Department, and the Sherburne County Sheriff's Non-
Emergency Services Division. The Elk River Police Department shall ensure that
downstream residents receive notification in the case of a Level 1 Emergency situation.
Communication will be achieved by phone, or by door-to-door notification. The Elk
River Fire and Police Departments will activate the Elk River Emergency Operations
Center.
Elk River Municipal Utilities is authorized to contact all other state and local officials as
necessary, including (but not limited to): the National Weather Service, the Minnesota
Department of Natural Resources, the Elk River Public Works Department, and the Elk
River City Administrator. If a situation arose in which Elk River Municipal Utilities could
not be reached, authority to contact all other state and local officials would fall to Elk
River Police and Fire Departments.
The National Weather Service (Twin Cities, MN Weather Forecast Office) shall issue
flood warnings in the case of a Level 1 or Level 2 Emergency.
C. Responsibility for Evacuation
The Elk River Police Department is responsible for evacuation of downstream residents
in case of a Level 1 Emergency. Although the list of residents that fall within the
theoretical inundation area will be updated regularly by the EAP coordinator, it could
possibly be incomplete at any future time. Evacuation should, therefore, include all
residents within or near the inundated areas (shown on the map in Section VII) and not
exclusively the residents on the notification flowchart.
D. Responsibility for Duration, Security, Termination, and Follow-Up
Elk River Municipal Utilities will be responsible for on-site monitoring of the situation at
the dam and keeping local authorities informed of developing conditions at the dam
from the time that the emergency starts until the emergency has been terminated. In
the case of a Level 1 or Level 2 Emergency, assistance may be requested of the DNR
for expert supervision and monitoring of a situation.
During a Level 1 or Level 2 Emergency, access to the dam shall be restricted by means
of temporary barriers and fencing.
June 6, 2014 Page 10
54
A Level 1 or Level 2 Emergency at the Elk River Dam will not be terminated until
inspected by a qualified engineer, and the DNR State Dam Safety Engineer has been
consulted. Only once the DNR has declared that an emergency is terminated shall Elk
River Utilities utilize the notification flowchart so that all notified parties are made aware
of the end of the emergency condition.
After termination of an emergency, a qualified engineer should inspect the dam for any
damage. A post-disaster review of the inspection will be held with the DNR State Dam
Safety Engineer to determine what actions may be needed to ensure that the dam is in
compliance with state standards. This review may result in formal orders issued to the
dam owner and may require the submittal of plans and specifications for repair.
A follow-up evaluation should be held as soon as possible following an emergency
event. This evaluation shall address events prior to, during, and following the
emergency; significant actions taken by each participant; what improvements would be
desirable for future emergencies; and all deficiencies found in procedures, materials,
equipment, manpower, leadership, and funding. A post-emergency report should be
prepared by Elk River Municipal Utilities, issued to the DNR State Dam Safety Engineer,
and distributed to all organizations who participated in or have a direct interest in the
emergency. Any changes deemed necessary for the EAP will be made by Elk River
Municipal Utilities, and an updated EAP—including an updated Approval sheet—will be
distributed to all holders of the EAP.
E. EAP Coordinator Responsibility
Elk River Municipal Utilities shall serve as the EAP coordinator. As the EAP
coordinator, Elk River Municipal Utilities is responsible for preparing revisions to the
EAP, distributing the EAP to involved agencies and parties, establishing EAP training
seminars for dam tenders and other involved parties, and coordinating EAP exercises.
Elk River Municipal Utilities is the EAP contact should any of the involved parties have
questions about the plan.
VI. Preparedness
A. Surveillance
The Elk River Dam is not operated remotely- everything is manual. Conditions
indicating a possible emergency situation and the potential for dam failure are outlined
in Table 2, and can be observed via daily inspection. The dam tenders must also be
able to identify potentially dangerous flow conditions. Potential flood conditions are
characterized by: extended periods of greater than average precipitation or combined
melting periods greater than average precipitation; and rapidly increasing headwater
levels (greater than 2 inches increase per hour). Factors which require consideration in
light of potential emergency flood situations include: initial water elevation and gate
operation; previous weather history; and predicted weather.
June 6, 2014 Page 11
55
B. Response During Periods of Darkness
The Elk River Dam is equipped with lights. Hand-held lights and/or generator-powered
floodlights can be used to aid in illumination of the dam, and will be provided by Elk
River Municipal Utilities in the event of a power failure. Should an emergency be
identified during a power failure, it may be necessary for notification to occur via
handheld radios, cell phone numbers, or in person.
C. Access to the Site
The primary means of accessing the Elk River Dam is by the embankments which abut
either end of the Main Street Bridge over the Elk River, with access to the observation
deck at the northeast end, and access to the gates from the southwest end. Access to
the upstream face of the dam can also be made by boat on Lake Orono.
The most direct route for personnel from Elk River Municipal Utilities, the Elk River
Police Department, and the Elk River Fire Department to access the site is via Orono
Parkway and Main Street. This route has a distance of approximately 3/4 of a mile, a
travel time of two minutes, and approaches the dam from the southwest. Should
access be required at the northeast end of the dam but the bridge is unavailable, the
shortest route is via Orono Parkway, Joplin Street, Highway 10 East, Upland Avenue,
and Main Street. This route has a distance of approximately 2.2 miles, and a travel time
of five minutes.
The most direct route for personnel from the Sherburne County Sheriff's Department is
via Business Center Drive Northwest, Joplin Street, Orono Parkway, and Main Street.
This route has a distance of 2.0 miles, a travel time of five minutes, and approaches the
dam from the southwest. Should access be required at the northeast end of the dam
but the bridge is unavailable, the shortest route is via Business Center Drive Northwest,
Joplin Street, Highway 10 East, Upland Avenue, and Main Street. This route has a
distance of approximately 2.2 miles, and a travel time of five minutes.
D. Response During Weekends and Holidays
In the event that a Level 1 or Level 2 Emergency is activated during a weekend or
holiday, it will be necessary to contact parties on the notification flowchart at their home
phone or cell phone numbers, if their primary number is not staffed 24/7.
E. Response During Periods of Adverse Weather
During adverse weather, it may be necessary to alter access to the dam, and/or contact
methods for parties in the notification flowchart. The dam is checked twice per day
during these periods.
June 6, 2014 Page 12
56
F. Alternative Systems of Communication
In the event that the primary system of communication fails, and/or parties cannot be
contacted via their primary contact number, it may be necessary to use alternative
channels of communication. Alternative means of communication shall include
handheld radios (800 MGHZ system), cell phone numbers, or in-person contact.
G. Emergency Supplies and Information
Emergency Operations Center
1. Stockpiling Materials and Equipment
Dam repair materials and equipment are not stockpiled at the dam for potential
emergency situations, but many resources are available within 1.5 miles of the
site. Sources for these and other items have been identified, and are outlined
below.
2. Coordination of Information
Operation of the Elk River Dam is overseen by Elk River Municipal Utilities. In
the event of a Level 1 or Level 2 Emergency, the National Weather Service (Twin
Cities, MN Forecast Office) should be coordinated with in order to monitor
storms, river stages, and flood waves resulting from a dam break.
If it becomes necessary to lower the reservoir water surface elevation during an
emergency, the Elk River Municipal Utilities will coordinate with the DNR State
Dam Safety Engineer in order to ensure that the drawdown is done in the most
safe and effective manner possible.
Actions that reduce inflow to the reservoir through coordination with upstream
dams do not apply to this EAP.
Actions that reduce downstream flows through coordination with downstream
dams do not apply to this EAP.
3. Other Site-Specific Actions
At a Level 1 emergency, the Emergency Operations Center would be opened.
VII. Inundation Maps
The purpose of an Inundation Map is to provide a picture of the area that would be
affected by a complete failure of the dam in order to determine who must be notified
and/or evacuated in an emergency. The Inundation Map should clearly identify
residences, businesses, storage facilities, bridges, downstream dams and other
structures such as roads, power lines, sewer, gas and water lines and other
June 6, 2014 Page 13
57
infrastructure that could be affected by the failure of the dam. There are currently 25
houses and that could potentially be affected. There are also two bridges (Main Street
and Parrish Avenue Northwest/County Road 42) that could potentially be affected.
The Inundation Map for the Elk River Dam was produced by Warzyn Engineering Inc. in
1989 based on the information from the Dam Failure Analysis. The Inundation Map—
which also shows the potentially affected structures—can be found on the following
page.
For further information on the method used to produce the map, please contact Warzyn
Engineering Inc.
June 6, 2014 Page 14
58
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VIII. Appendices
Appendix A — Investigation and Analyses of Dambreak Floods
Appendix B — Plans for Training, Exercising, Updating, and Posting the EAP
Appendix C — Site-Specific Concerns
Appendix D —Approval of the EAP
Appendix E — List of Holders of the EAP
June 6, 2014 Page 16
60
APPENDIX A
Investigation and Analyses of Dam Break Floods
61
NOTE: Dam Failure Analysis (DFA) report to be provided by Elk River Municipal Utilities.
62
APPENDIX B
Plans for Training, Exercising, Updating, and Posting the
EA P
63
Training
Training shall be conducted to ensure that parties involved in implementation of the EAP are
familiar with all elements of the plan, the availability of equipment, and their responsibilities and
duties under the plan. A careful record and roster for each training should be maintained.
An annual training shall be held for Elk River Municipal Utilities personnel involved in dam
activities and operation. This training should prepare personnel for problem detection and
evaluation, how problems relate to determining the appropriate emergency level, and
appropriate responses during emergency situations. This training should also be held within 30
days after assignment of new dam operation personnel.
An annual review of the EAP will be conducted for all involved parties. The purpose of this
training will be to train parties in the procedures to follow in the event of an emergency, to
answer questions regarding the procedures, and to test understanding of the EAP. Feedback
shall be obtained during this review and be taken into account during update of the plan.
Exercising
On an annual basis, a test of the emergency preparedness of dam operating personnel and
other parties involved in implementation of the EAP shall be made to evaluate the effectiveness
and understanding of the EAP. These exercises will include an annual drill, as well as periodic
tabletop and functional exercises, all of which should include participation by all parties in the
notification flowchart. During these exercises, the dam owner and operator will choose a
hypothetical situation to which the appropriate procedures and responses will be determined by
each involved party. Upon completion of each exercise, Elk River Municipal Utilities will verify
that the plan is adequate and, if not, will revise the EAP based on the comments and outcome
of the evaluation.
Updating
A review of the adequacy of the EAP shall be conducted at least annually. During this review,
an evaluation of any changes in flood inundation areas, downstream developments, or in the
reservoir should be made to determine whether any revisions to the current EAP (including
inundation maps) are necessary. The EAP should be updated promptly after each change in
involved personnel or their contact information, or after completion of the exercises or trainings.
If no revisions are necessary within a given year, a statement that the review was made and no
revision to the EAP was necessary should be provided to each recipient of the original EAP.
Copies of any revisions that do result from updating the EAP should be furnished to all
individuals to whom the original EAP was distributed. The list of EAP holders in Appendix E
should be followed to ensure that all copies of the EAP are revised.
Posting
An up-to-date copy of the notification flowchart shall be posted on the observation deck at the
dam and at the Elk River Emergency Operations Center. Copies of the complete EAP are also
held by all of the parties in Appendix E.
64
APPENDIX C
Site-Specific Concerns
65
Flood Data
Flood warning and flood forecasting services in the Elk River area are provided by the National
Weather Service Forecast Office at Minneapolis. Technological support is provided by a staff of
professional hydrologists at the North Central River Forecast Center also located in
Minneapolis.
Lead time between distribution of flood forecasts and arrival of the flood crest may range from a
few hours to several weeks, in the case of snowmelt. Lead time for crests resulting from rainfall
is normally 3 to 7 days, depending on the area and magnitude of the storm.
Floods of record in the Elk River Basin have historically occurred in March, April and May as a
result of rapid snowmelt. The worst conditions will occur when rainfall accompanies the
snowmelt. The most common indication of a potentially hazardous spring flood will be a
snowpack greater than 18 inches in the drainage basin. If a rapid warming trend occurs under
these conditions, a flood is highly probable. The peak flood flow under these conditions will
generally occur about 7 days after the start of snowmelt, which allows adequate time for
preparation. The worst conditions will occur if a rainstorm accompanies the warming trend.
Under these conditions, advance notice may be reduced to a few days or less, depending on
the area, magnitude, and distribution of the rainfall.
When the reservoir elevation is high or during floods, the City of Elk River should maintain
communications with the National Weather Service in Minneapolis. The National Weather
Service will provide details regarding river stages and flows upstream from the dam and
anticipated weather conditions.
Whenever conditions that may cause a flood appear to be developing, the City should keep in
touch will all of the sources mentioned above in order to maximize lead time for flood
preparation at Elk River Dam. The City should also coordinate efforts with the National Weather
Service and local agencies in disseminating flood information to residents in the flood plain.
Structural Drawings
Structural drawings can be obtained by request from Elk River Municipal Utilities.
Gate Operation
This section describes the radial gate operation plan during flood or other periods of high water
elevation. The gates should always be operated in general accordance with the operation plan
described here, or in a separate Inspection, Operation, and Maintenance Manual. During
extreme floods, some deviation from the operation plan may be required. Such deviation should
only be permitted when the reservoir water surface rises very rapidly and normal gate operation
procedures are impractical. A complete description of the gate operation plan is presented
below, with a graphic following:
• Always clear the downstream area of any personnel at or near river level before opening
a gate.
• When the reservoir level reaches elevation 875.0 feet and rising, open Gate No. 2
(middle gate) approximately 6 feet. To open the gate 6 feet, the electrical operator
should be engaged for approximately 8 to 9 minutes. The gates can also be opened
manually with the handwheel: 670 rotations of the stem nut will open the gate
66
approximately 6 feet. The amount of gate opening can also be estimated by visually
observing the take-up on the wire cables on the drum hoist. When the gate is open 6
feet, the top of the gate will be approximately 1 foot lower than the top of the operation
deck.
• If the water surface elevation rises to 875.5 feet, maintain Gate No. 2 at 6 feet and open
Gate No. 1 (south gate, farthest from the main weir) 6 feet. Close the Main Street Bridge
to all traffic except emergency vehicles if this has not already been done.
• If the water surface elevation rises to 876.2 feet, maintain Gates Nos. 1 and 2 at 6 feet
and open Gate No. 3 (north gate, nearest to the main weir) to the full open position. (All
gates are equipped with switches that will automatically shut off when the gate reaches
its full open position.) Close the Main Street Bridge to all traffic if this has not already
been done.
• If the reservoir water surface elevation rises to 877.0 feet, maintain Gate No. 3 full open
and open Gates Nos. 1 and2 to the full open position.
• If the reservoir water surface lowers to elevation 871.3 (crest of the overflow weir) at any
time during opening of the gates, then begin closing the gates. Close only one gate at a
time. Close Gate No. 3 first, followed by Gate No. 1, and finally Gate No. 2. Close the
second and third gates only after the previous gate has been closed completely and the
reservoir water surface is at or below 871.3 feet and continuing to drop.
Never stop the gates when water is flowing over the top and under the bottom at the same time.
When open, the top of the gate should be well above the reservoir water surface elevation. If
water flows both over and under the gate at the same time for a prolonged period, vibration may
damage the gate.
NOTE: The fuse plug dikes are designed to be overtopped and erode during extremely large
floods. The increase in reservoir level caused by inflowing flood water will be delayed by this
erosion, and the impact of the flood flow downstream will consequently be reduced. The fuse
plug dikes are constructed of fine sand and silty sand and have been seeded to provide a lawn
area and prevent surface erosion. Neither sand bags nor any other type of erosion protection
should be placed on the embankments to prevent overtopping.
67
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APPENDIX D
Approval of the EAP
69
Approval of the EAP
By my signature, I acknowledge that I, or my representative, have reviewed this plan and concur
with the tasks and responsibilities assigned herein for me and my organization.
1. City of Elk River
Printed name and title:
Signature Date
2. Elk River Municipal Utilities
Printed name and title:
Signature Date
3. Elk River Police Department
Printed name and title:
Signature Date
4. Elk River Fire Department
Printed name and title:
Signature Date
5. Sherburne County Sheriff's Communications Division
Printed name and title:
Signature Date
6. Minnesota Department of Natural Resources
Printed name and title:
Signature Date
70
APPENDIX E
List of Holders of the EAP
71
List of Holders of the Elk River EAP
# of Name Address
Copies
72