Decision details

River Itchen Flood Alleviation Scheme

Decision Maker: Cabinet

Decision status: Recommendations Approved

Is Key decision?: Yes

Is subject to call in?: Yes

Purpose:

To consider the report of the Cabinet Member for Environment in consultation with the Cabinet Member for Growth detailing considerations regarding the alignment of the flood alleviation scheme.

Decision:

(i)  To note and recommend to Council the option; a mix of setback and frontline flood defences.

(ii)  To note this option involves a contribution of £3M from the Council to secure scheme funding of £31.5M from a Flood and Coastal Erosion Risk Management (FCERM) grant-in-aid (GiA) external grant.

(iii)  To note and recommend to Council the approval of the alignment on Drivers Wharf as a frontline.

(iv)  To note this option involves a further contribution of £7.2M from the Council, bringing the total contribution to £10.2M, to be funded from CIL in full.

Reasons for the decision:

1.  Current flood risk to 153 homes, 288 businesses, short sections of mainline railway, parts of the A3024 Northam Road, and various critical infrastructure sites (electrical sub-stations, pumping stations). By 2120, the flood risk increases to 1,167 homes and 1,033 businesses, with potential flood depths of up to 1.8m.

2.  Better protection to Northam Estate, a large SCC housing stock and community within 10% most deprived areas in England.

3.  Improve the opportunity for regeneration by reducing flood risk to the area, without precluding development of waterside sites in the future. 

4.  Replacement of SCC owned quay wall at Drivers Wharf required within 10 years.

Alternative options considered:

1.  Do Nothing (£0) – no intervention. Rejected as leaves homes (including SCC Housing stocks) and businesses exposed to present-day flood risk. Drivers Wharf quay wall at risk of failure within 10 years.

2.  Full setback (£27.1M) – a raised wall with an alignment taking the shortest viable route across the scheme area. Rejected as it leaves large areas at risk of flooding. Drivers Wharf quay wall at risk of failure within 10 years.

3.  Full frontline (£122.9M) – new raised wall (steel sheet plies) along the length of the riverbank. Rejected as unaffordable.

Report author: Cara Brims

Publication date: 15/11/2021

Date of decision: 15/11/2021

Decided at meeting: 15/11/2021 - Cabinet

Effective from: 24/11/2021

Accompanying Documents: