Skip to content





Sea surges and high waves <h2 class="sectHeading">​What causes surges and high waves?</h2><p>Water is pushed towards the sea shore by the force of the winds swirling around the storm. This advancing surge combines with the normal tides to create the hurricane storm tide, which can increase the main water level by up to 4 metres or more in height. This rise in water level may cause severe flooding in coastal areas, particularly when the storm tide happens during normal high tides.</p><div class="notification with-heading dark-copy light-blue bg-light-grey"><div class="graphic with-border"> <i class="info fastfact"></i> </div><div class="desc"><h4>Fast fact</h4><p>Storm surges also affect rivers and inland lakes, potentially increasing the area that may have to be evacuated.</p></div></div><h2 class="sectHeading">Be prepared </h2><p>Nobody can stop a surge or flood, but if you are at risk, there are actions you can take before, during and after to protect your family and reduce damage to your property and belongings. The most important thing is to make sure your family is safe.</p><p>By drafting your own family emergency plan and identifying all your risks, you are in a much better position for any disaster. Complete our <a href="" target="_blank">Family Disaster Preparedness Guidelines</a> and make sure everyone knows where it is. Also see the <a href="" target="_blank"> Disaster Preparedness Guide for People with Disabilities Pamphlet</a>.</p><p> <b>Time permitting, these steps can be taken before a storm surge or flooding arrives:</b> </p><ul><li>Turn off all utilities at the main power switch and close the main gas valve if evacuation appears necessary.</li><li>Move valuables, such as documents, jewellery, clothing and photographs to upper floors or higher elevations.</li><li>Fill bathtubs, sinks and plastic bottles with clean water. Sanitise the sinks and tubs first by using bleach, rinse, then fill with clean water.</li><li>Bring outdoor possessions such as lawn furniture, grills and refuse bins inside, or tie them down securely.</li></ul><h2 class="sectHeading">Evacuation route</h2><p> <strong>Plan and practice an evacuation route:</strong></p><ul><li>Learn the warning signs and your community's alert signals.</li><li>People living in potential flash flood areas should have several alternative routes.</li><li>Request information on preparing for storm surges and floods.</li></ul><h2 class="sectHeading">Develop an emergency communication plan</h2><p>In case family members are separated from one another during floods or flash floods (a real possibility during the day when adults are at work and children are at school), have a plan for getting back together.</p><p> <b>Here are some of our recommendations:</b> </p><ul><li>Ask an out-of-town relative or friend to serve as the "family contact." After a disaster, it's often easier to call long distance.</li><li>Make sure everyone in the family knows the name, address and phone number of the contact person.</li><li>Teach all family members how and when to turn off the gas, electricity and water.</li><li>Teach children how and when to call emergency numbers (police, ambulance, fire and rescue services, electricity and water services), and which radio station to tune into for emergency information. See our <a href="">list of emergency numbers</a>. </li><li>Be prepared to evacuate at any time.</li></ul><span></span><h2 class="sectHeading">Have disaster supplies on hand</h2><p> <strong>You should include the following:</strong></p><ul><li>Torches and extra batteries</li><li>Portable, battery-operated radio (and extra batteries) tuned to a local station so you can follow any emergency instructions</li><li>First aid kit and manual</li><li>Emergency food and bottled water</li><li>Non-electric can opener</li><li>Essential medicines</li><li>Cash and credit cards</li><li>Strong shoes</li><li>Cell phones</li><li>Dry clothing</li></ul><p><strong>If you live in a coastal area with a high risk of flooding, keep stock of emergency building materials:</strong></p><ul><li>Plywood</li><li>Plastic sheeting</li><li>Timber</li><li>Nails</li><li>Hammer and saw</li><li>Pry-bar</li><li>Shovels</li><li>Sandbags</li></ul><div class="notification with-heading dark-copy pink bg-light-grey"><div class="graphic with-border"> <i class="info toptip"></i> </div><div class="desc"><h4>Top tip</h4><p>Have check-valves installed in building sewer traps to prevent flood waters from backing up in sewer drains.</p></div></div><h2 class="sectHeading">Inspecting a damaged home</h2> <b>Check for gas leaks:</b> <p>If you smell gas or hear a blowing or hissing noise, open a window and quickly leave the building. Turn off the gas at the outside main valve if you can, and call the gas company from a neighbour's home. If you turn off the gas for any reason, it must be turned back on by a professional.</p> <b>Look for electrical system damage:</b> <p>If you see sparks or broken or frayed wires, or if you smell hot insulation, turn off the electricity at the main fuse box or circuit breaker. If you have to step in water to get to the fuse box or circuit breaker, call an electrician for advice.</p> <b>Check for sewage and water line damage:</b> <p>If you suspect sewage lines are damaged, avoid using the toilets and call a <a href="">qualified, registered plumber​</a>. If water pipes are damaged, contact the water department and avoid the water from taps. You can obtain safe water by melting ice cubes.</p>GP0|#a30e2ee6-fe76-4ea5-913f-b416a7239cce;L0|#0a30e2ee6-fe76-4ea5-913f-b416a7239cce|Sea surges and high waves;GTSet|#ef3a64a2-d764-44bc-9d69-3a63d3fadea1;GPP|#e1eec47d-9c40-4859-a001-a519b50f3e4a;GPP|#df0a3405-0ca1-4617-8047-15a034219fee;GPP|#245ec7aa-a528-4cd3-bcac-597c292db711;GP0|#f2b0cc66-c0d6-44b0-bb7d-7b852cf25f8b;L0|#0f2b0cc66-c0d6-44b0-bb7d-7b852cf25f8b|Sea surges and high waves;GPP|#c6d118c1-4a38-4635-ae3d-bf9f7ef0f2a3;GPP|#36dcb5fe-6bfc-4ae9-92d7-8bd08d1f6414;GPP|#af370586-9ba3-404a-9d6e-02066ca42752An overview of sea surges and dangerous waves, and what you can do to keep yourself and your family safe.





You have disabled JavaScript on your browser.
Please enable it in order to use City online applications.