The Government has information on how to prepare for flooding, and what to do before, during, and after a flooding event - Flooding - GOV.UK (www.gov.uk)

During a flooding event, we recommend that you: 

• Deploy any flood protection measures if safe to do so
• Protect entry points, including doorways and any air bricks with flood protection barriers
• If you don’t have flood protection barriers, consider homemade alternatives.
  • Use a bin liner filled with soil, on a tarp, as a sandbag
  • Use waterproof tape (like duct tape) to cover airbricks
  • Use a plastic bag full of rags and a weight (like a brick) to bung drains
  • Use a plastic bag full of rags, or a deflated football, to block toilets
• Protect basements or cellars. They can be sealed using a ‘tanking’ system to make them completely waterproof. Basements may also need a pump for any water that seeps through.
• Move people, pets and valuable items upstairs or in a high place downstairs
• Do not walk or drive through flood water. If you must walk through flood water, use a stick to check for obstacles, and (once safe to do so) remove contaminated clothing and wash with soap and water
• If evacuating, turn off your gas, electricity and water supply
• Check any vulnerable family members, friends or neighbours who might need help moving possessions or deploying property defences. Vulnerable residents can sign up for extra support via the Priority Services Register – contact your utilities company or visit www.thepsr.co.ulk for more information. 

Property owners are responsible for protecting their own premises and are strongly advised to purchase their own supply of sandbags or install property flood resilience products in advance of any flood event.

Sandbags can be obtained from DIY stores and builders’ merchants.

The council only has a limited stock of sandbags which are reserved to help our most vulnerable residents if their home is at threat of internal flooding.  

We are not able to issue sandbags to individual homes and businesses.  

The Environment Agency is responsible for managing flooding from main rivers and the sea. It also issues warnings and maintains flood maps. 

Hampshire County Council are the Lead Local Flood Authority (LLFA) in the area. This means they are responsible for managing the risk of flooding from surface water (rainfall) run off, groundwater flooding, and ordinary watercourses. This includes smaller, non-main rivers and water bodies such as streams, ditches, drains, culverts and sluices. 

As the highway authority, they are also responsible for flooding on the highway and for maintaining the drainage system within and under the roads.

Flooding on Motorways and major A roads is the responsibility of National Highways. 

Water companies are responsible for flooding from public sewers. 

Riparian owners: if you have a ditch or watercourse either on or adjacent to your property, you are probably responsible, under common law, for its maintenance. You can find out more information on your responsibilities from the government website

Dial 999 if it is an emergency and you or someone else is in danger

Different agencies are responsible for managing different forms of flooding. Reporting a flood event to the correct authority who are responsible for managing the risk helps the issue to be investigated promptly. 

• If the water is coming from the highway, report to Hampshire County Council. You can call 0300 555 1388 or use the online form (selecting option “road, pavement, cycle path, drain”).  
• If the water is coming from a main river or sea, contact the Environment Agency. You can call them on 0800 80 70 60
• If there is a burst or leaking foul sewer main, contact Southern Water on their website or call customer services on 0330 303 0368 
• If the source of the flooding is from someone else’s property, report it to HCC and choose the option “Private land, property boundary ditch or roadside ditch”

You can contact Hampshire County Council as the Lead Local Flood Authority on fwm@hants.gov.uk or on 01962 846 730

Following significant investment in flood defences from the Winchester City Council Community Infrastructure Levy (£800,000) and the Environment Agency (£548,000), which saw works complete 2021, Winchester city has a number of protections in place in the event of severe flooding.

The council own and operate the flood defences in Winchester City, whilst the flood alleviation measures in Hambledon are owned and maintained by Hampshire Highways. 

The rivers and tributaries throughout Winchester are checked every day of the year, but in spate (sudden flood) conditions they are checked more regularly. In extreme weather, the culverts under the city are closed off to river water, allowing additional capacity for rainwater to ensure that surface water drains located in the city can continue to operate. 

There are a number of sluice gates throughout the city that are continually checked for blockages and adjusted by our engineers to manage the flow of water. The sluices permit maximum safe flow and, where required, additional temporary measures are also supplied to help people navigate any excess water, for example, the walkway over the large puddle in River Park.

Low-level flooding - the Winnall Moor Flood Plain

The first stage of flooding in Winchester happens when the river bursts its banks and starts to flood Winnall Moor. This first stage is an entirely normal and expected activity and shouldn’t cause concern. Winnall Moor is an active floodplain and regularly floods in this way – it commonly happens during the winter months. The water then runs down through the river tributaries such as the one in Abbey Gardens. 

Phase 1 Defences

In the event of the river rising to the point that flooding in the city may be an issue, then the Phase 1 defences may be implemented. Phase 1 defences are a system of walls, bunds, temporary barriers, and one-way valves that protect St Bedes School, the university and Park Avenue residents, as well as the residents of Water Lane. The only notable impact of the phase 1 defences on residents is that access through Park Avenue and the river walk along Water Lane is blocked, and flooding will occur in River Park.

The Phase 1 barriers may often be installed as a precaution, with one panel removed to permit access until flooding is expected and the barrier is actually required, at which point the last panel can quickly be installed to complete the defence. We would ask that residents do not climb over these temporary defences as the barriers are not designed to withstand this activity and, if damaged, flooding of properties may well result. Access can instead be gained by using a small diversion via Gordon Road.

Phase 2 Defences

Phase 2 defences are designed to protect Winchester, even in the event of a 1-in-100-year storm. If significant flooding is expected then, in conjunction with the Environment Agency, Phase 2 defences may be implemented in addition to Phase 1 defences. Phase 2 involves placing sluice controls on all the river channels entering the city, restricting flow to a safe level and holding back the excess water.

The Phase 2 defences provide an unbroken continuous flood defence from Gordon Road to Easton Lane, storing up to 7 days’ worth of flood water on Winnall Moors. The Phase 2 defences give valuable additional time to evacuate residents and prepare properties for any flooding.

Implementing Phase 2 does involve the deliberate flooding of Winnall Moor. As the moor is a Site of Special Scientific Interest (SSSI) and Special Area of Conservation (SAC), phase 2 defences will only be implemented with the agreement of the EA if there is a risk of serious, life-threatening flooding.