Proposal to Create a Wetland in Micheldever

Following positive feasibility surveys, Winchester County Council are planning to develop a passive wetland to generate nitrates credits for their planning applications because the land outlined is not suitable for housing development due to flood risk. The scheme will also benefit local residents by providing an improved visual amenity and significant environmental benefits including increasing biodiversity by creating valuable wildlife habitats.

Aquascience – wetland ecology specialists – have designed the scheme, image copied below. Essentially, the plan is to: • Divert water from the east of the council’s land from the ditch behind the houses in Barron Close • Channel water through a series of four scrapes / unlined ponds that will filter the water • Return cleaner water (nitrogen removed) to the carrier stream to the north of the council’s site

The water in the ditch contains effluent from the sewage treatment works and is already safe but by filtering through the wetland will remove more nitrogen and generate credits.

Winchester Housing Trust were contacted and there is general support for the scheme. The design includes laying a small section of pipe under scrubland owned by WHT, behind their houses in Barron Close; this will help because there is minimal fall across the site.

The wetland and pipes will be maintained by the council and if there is a blockage and / or if there is very heavy rainfall, water will just revert to its original course – flowing into the carrier stream via the pond that would be bypassed just north of the site. The report explains how the scheme will alleviate flooding by increasing the flood storage capacity on the site.

Next steps include sharing these plans with the local community before applying for planning permission and watercourse consent.