Emergency Action Plan (EAP) Tata Pond Dam

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Connecticut Name of Dam Owner Dam Hazard Classification is B Reviewed and Updated:

1 For Official Use Only Not for Public Distribution 02/03/16 Emergency Action Plan (EAP) Tata Pond Dam State of Connecticut Dam ID: 0000 Town or City, County, Connecticut Name of Dam Owner Dam Hazard Classification is B Reviewed and Updated: Dam Owner or Owner s Representative Emergency Management Director, Town or City, CT Date Date Copy of

2 Description Table of Contents Page 1 Basic EAP Data Purpose General Dam Description Directions to Dam Emergency Conditions Breach Modeling Assumptions Potential Impacted Area Roles and Responsibilities Dam Owner s Representative Dam Operator s Representative State Dam Safety Agency Incident Commander Norfolk Local Emergency Operations Center (LEOC) The Five-step EAP Process Step 1 - Event Detection Step 2 - Emergency Level Determination Emergency Level 1: Nonemergency, unusual event, slowly developing Emergency Level 2: Potential dam failure situation, rapidly developing Emergency Level 3: Urgent; dam failure appears imminent or is in progress Guidance for Determining the Emergency Level Examples of Emergency Situations Step 3 - Notification and Communication Notification Communication Notification Charts Emergency Level 1 Notifications Emergency Level 2 Notifications Emergency Level 3 Notifications Emergency Services Contacts Step 4 - Expected Actions Emergency Level 1: Nonemergency, unusual event; slowly developing Emergency Level 2: Potential dam failure situation; rapidly developing Emergency Level 3: Urgent; dam failure appears imminent or is in progress Step 5 - Termination...23 Tata Pond Dam (No. 0000), Town or City, County, CT I-i

3 Description Table of Contents (Continued) Page 4 Maintenance - EAP Review and Revision EAP Call Out Exercise EAP Tabletop Exercise Revisions Record of Holders of Control Copies of this EAP Record of Revisions and Updates Made to EAP... 2 Concurrences... Appendices Appendix A 1 Appendix A 2 Appendix A 3 Appendix A 4 Appendix B 1 Appendix B 2 End of Report Contact Checklist... (1-2 pages) Unusual or Emergency Event Log Form... (1 page) Dam Emergency Termination Log... (1 page) Glossary of Terms... (5 pages) Resources Available... (1 page) Aerial, Location and Watershed Maps... (2 pages) Appendix B 3 Evacuation Maps... (1-10 pages, 11 x ) Appendix B 4 Residents/Roads at Risk Table... (1-6 pages) Appendix B 5 LEOC and Emergency Shelter Addresses... (1 page) Appendix B 6 Plan-Profile of Tata Pond Dam... (1-4 pages, 11 x ) Appendix B Flood Inundation Summary Table... (1-3 pages) Tata Pond Dam (No. 0000), Town or City, County, CT I-ii

4 For Official Use Only Not for Public Distribution 02/03/16 1 Basic EAP Data 1.1 Purpose The purpose of this Emergency Action Plan (EAP) is to provide advanced warning of a potential failure of Tata Pond Dam to allow time to take mitigating action to prevent a dam failure, and to minimize the loss of life and injury from a dam failure. This EAP is to be used in conjunction with the Town or City Emergency Operations Plan (EOP) and guidelines. 1.2 General In order to accomplish the above purpose, an inspection and monitoring program is to be established including both routine inspections and monitoring during severe storm events. This EAP defines responsibilities for inspections and notifications, provides procedures for identifying conditions that could result in failure of the dam, and provides mapping of the potential inundation area from a dam failure (evacuation area). The Glossary of Terms can be found in Appendix A-4. This EAP should be distributed to the appropriate emergency management officials with adequate explanation to place the hazard potential of the dam in its proper perspective. The local emergency management officials are responsible for warning and evacuating the downstream residents if a dam failure is imminent. The EAP should be exercised periodically to assure that all phases work as intended. Section 4 describes the training and exercising of the EAP to improve the close coordination necessary for a successful execution of emergency procedures during an emergency. This EAP should be reviewed biennially and modified, if found necessary, as noted in Section 4. The review should verify personnel assignments, any change in emergency management officials to be notified and/or telephone numbers, significant development or construction activity downstream of the dam, or modifications to the dam and/or spillway. 1.3 Dam Description Tata Pond Dam consists of an earthen embankment, concrete spillway and training walls, and a lowlevel outlet with a sluice gate and weir boards. The upstream slope is riprapped above spillway level with grass cover on the remaining upstream slope, dam crest, and downstream slope. A footbridge spans the principal spillway and a vehicle access gate is located on the left abutment. Tata Pond Dam (No. 0000), Town or City, County, CT Page 1

5 For Official Use Only Not for Public Distribution 02/03/16 Built/Upgraded: 16/16 Connecticut Dam ID No.: 0000 Height: 0 feet Dam Operator: Operator Name Drainage Area: 0 mi 2 Major Property Owner: Property Owner Name Impoundment Area: 0 acres Spillway Length: 0 feet Hazard Classification: Class B Significant Purpose: Recreation Latitude: 00 00'00"N Longitude: 00 00'00"W Outflow Location: Howard Creek 1.4 Directions to Dam Tata Pond Dam is located in Town or City, CT. Directions to the dam are as follows: (See Location, Watershed, and Aerial Maps; [Appendix B 2].) 1.5 Emergency Conditions Emergency conditions at the dam may be caused by any one of at least four different conditions: Excessive precipitation Seepage, including internal erosion and/or piping Earthquake Sabotage The spillway at Tata Pond Dam can safely discharge floods with recurrence intervals in excess of 100 years. As the dam would not be overtopped by one-half the probable maximum flood (1/2 PMF), the most likely cause of failure is excessive seepage resulting in internal erosion or piping through the embankment. This condition should develop gradually and could occur at any time, although it is more likely during a severe storm when the pond level is above normal and causing additional pressure on the dam. The majority of this EAP document is predicated on the presumption that the cause of the emergency condition is seepage and internal erosion associated with excessive precipitation. Should advance warning be available for any of the other conditions, the evacuation area, emergency procedures, and notification listing would be equally applicable. Tata Pond Dam is located in Seismic Zone 2A. Intensity of earthquakes in this zone are predicted to result in moderate damage. Tata Pond Dam (No. 0000), Town or City, County, CT Page 2

6 For Official Use Only Not for Public Distribution 02/03/16 The EAP includes: Actions the dam owner will take to moderate or alleviate a problem at the dam; Actions the dam owner will take, and in coordination with emergency management authorities, to respond to incidents or emergencies related to the dam; Procedures dam owners will follow to issue early warning and notification messages to responsible downstream emergency management authorities; Inundation maps to assist dam owners and emergency management authorities identify critical infrastructure sites and population at risk that may require protective measures, warning, and evacuation planning; and Delineation of the responsibilities of all those involved in managing an incident or emergency and how the responsibilities should be coordinated. 1.6 Breach Modeling Assumptions The Limits of Potential Flooding for failure of Tata Pond Dam were calculated under the following conditions: The pre-breach water level in Tata Pond is at the crest of the dam; There is significant flooding of Howard Creek from uncontrolled drainage areas; There is unobstructed flow through downstream bridges; The antecedent flow in the downstream channel was set equal to the 500-year FEMA flood flows; and A 2 foot differential exists at the downstream limits of potential flooding. This is a conservative estimate, but not the largest possible breach. If conditions exist that would result in a larger breach (such as a higher lake level), or if breach wave debris (such as trees, cars, structures, etc.) clog the bridge crossings, additional nearby properties may need to be evacuated. The limits of potential flooding used in the preparation of this EAP were derived using the US Army Corp of Engineers HEC-RAS computer program. 1. Potential Impacted Area See Evacuation Maps [Appendix B 3] and Resident/Roads at Risk [Appendix B 4] for the locations of the residents and roads along Howard Creek that may be flooded if the dam should fail. The Flood Inundation Summary Table [Appendix B-] shows the approximate time for the flood crest to travel from the dam to each downstream section, the maximum estimated USGS elevation of the flood crest, the maximum estimated flow in cubic feet per second (cfs), the antecedent flow elevation and the increase in depth of flow at each section. Tata Pond Dam (No. 0000), Town or City, County, CT Page 3

7 For Official Use Only Not for Public Distribution 02/03/16 3 The Five-step EAP Process Tata Pond Dam (No. 0000), Town or City, County, CT Page 6

8 For Official Use Only Not for Public Distribution 02/03/16 Appendix B 3 Evacuation Maps Tata Pond Dam (No. 0000), Town or City, County, CT Page B5

Stone Dr 3 ³ 150 21 1501 1519 34 432 11 Angeli 16 433 154 Ct 89 1654 422 11 1664 < 14 412 Legend 39 24 02 166 9 144 AMTRAK 6 ' %90.8 90.

9 Stone Dr 3 ³ Angeli Ct < Legend AMTRAK 6 ' % Oconnell Dr Avoid - Bridge Bridge Crossing Prohibited Railroad <Flow Direction ' Limit of Potential Flooding Evacuation Area Cross Section Hours to Initial River Rise Hours to Peak Stage Mill Dam New AMTRAK % Orchard Rd 6 Park Dr 226 Watch Hill % Spruce Brook Rd Olisky Blvd Maryann Ct < Toll Gate Rd Howard Creek «15 5 Bishops Curve Bishops Curv Meadow Casne r Dr Berlin Tpke Wilbur Cross Hwy State Hwy ' US Hwy ' 14 ' Ln 33 Red Barn Ct % Jeffrey Ln 18 9 Holly Ct Tree Hill Rd 835 Kramer Dr Four Rod Rd Notes: - Base mapping consists of 12 Connecticut Color Orthophotos, Parcel data and Hydrography features from CT DEEP GIS databases. - For the purpose of clarity, cross sections used in the computations are not all shown. - Evacuation area based on inundation map resulting from a breach with water level at the top of the dam and downstream antecedent flow equal to the FEMA 500-year peak discharge. - Evacuation area includes properties cut off from emergency services due to a dam breach Fawn Dr Worthington Ridge Wilks Pond Rd Peter Parley Row Dunham Dr Jarvis Ln Valley Dr Lower Ln Sage Dr Wildermere Rd Pondside Dr Smoky Hill Rd % < 1 ' Cindy Ln orto Rd Deerfield Dr Sheet Index Figure No. Limits of Potential Flooding and Evacuation Area B-3 Tata Pond Dam, Town or City, CT - Dam ID No ,000 Feet Sheet 2 of 3 Owner Name February 16

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