A32 Farringdon-Chawton flood alleviation scheme

Works to reduce flooding in the Farringdon area

Latest updates

Works have now been completed works on the A32 by the Mary Lane/Newton Lane junction and this is the last package of works to be undertaken in 2023. The final work package (at 2 The Orchards and The Malt House) is subject to planning permission so if this is approved and if this is fully supported by various landowners, further work would be programmed. A significant amount of work has now been undertaken with seven work packages completed in this second phase of the flood alleviation works adding to the six work packages that were completed in the earlier Phase 1 works.

The planning application SDNP/23/03358/FUL for proposed works in 2 The Orchards and The Malt House was submitted to the South Downs National Park Authority in August and has yet to be determined. A non-technical note explaining the purpose and operation of the proposals within the planning application (summarising the presentation given to local residents and the parish council on Tuesday 19 September), is to be submitted to the planning authority and it is expected there will be a short consultation in due course to receive any comments on this document. Due to concerns raised at the evening meeting and to address the three objections to the planning application, further discussions with a few residents are ongoing.

Flooding overview

In the winter of 2013 to 2014, the A32 highway, Lower Farringdon, parts of Chawton and the surrounding area were badly affected by flooding from a combination of rising groundwater and surface water. There is a long history of flooding in this area and the primary cause of this is the height of groundwater which is recharged by rainfall. The level varies throughout the year and generally peaks between February and April.

Hampshire County Council has been working together with a number of different organisations including the parish councils, to understand the cause of the flooding. A number of actions were developed and undertaken in the short term to help alleviate flooding. These actions were funded by the County Council and The Environment Agency who contributed £292,000 and £120,000 respectively. These Phase 1 works informed the development of longer term mitigation strategy solutions that will provide a greater level of protection from flooding.

The works are to ensure the existing drainage system, which consists of ordinary watercourses, less well-defined overland flow paths, the main river and highway drainage can function to its maximum capacity. They include:

  • removing vegetation to ensure flow paths for water are clear
  • undertaking maintenance, clearance and surveying of existing ditches, culverts and pipes
  • replacing, upsizing and installing some new pipes or culverts

The improvements will reduce costs, reduce distress and disruption associated with future flooding, minimise the impact on the local economy and help to ensure that the highway network can remain open.

The organisations involved in the A32 Farringdon-Chawton multi-agency group are:

  • Hampshire County Council (as Lead Local Flood Authority and Highway Authority)
  • East Hampshire District Council
  • Environment Agency
  • Thames Water Utilities Limited
  • Farringdon Parish Council
  • Chawton Parish Council
Project appraisal and funding

The scheme has been approved via the following Project Appraisals and received a financial contribution from central government and the Thames Regional and Coastal Committee.

19 September 2017 Project Appraisal - £292,000

Summer 2020 - £317,000 contribution from the Environment Agency

23 September 2021 Project Appraisal - £386,000

12 May 2022 Updated Project Appraisal - £1.181m

Programme of works

The programme of works may need to change due to weather conditions or other unforeseen issues.

Milestone Timescale
Phase 1a: CCTV and land survey, trial hole investigations and ditching works Autumn/Winter 2017/18
Phase 1b: Culvert installation, further CCTV survey and some trial hole investigations Summer/Autumn 2019
Phase 1c: Emergency works carried out under Section 100 of the Highways Act during the flood event February-April 2020
Phase 2 investigations: CCTV and land survey, trial hole investigations Summer/Autumn 2021
Phase 2a: Culvert installation and ditching works (A32 Gosport Road (WP7) and Manor Farm (WP8)) Summer/Autumn 2022
Phase 2b: Culvert installation and ditching/swale works (A32 Gosport Rd (WP3/4/5) and Shirnall Hill (WP6)) Summer/Autumn 2023

Overview Plan showing the area of scheme works. The plan may take several seconds to load. It may change following further discussions with the highway contractor.

Phase 1 – showing location of completed works

Phase 2 – showing locations of planned works

Maintenance of ordinary watercourses

Watercourses are classified as either a ‘ordinary watercourse’ or ‘main river’. Ordinary watercourses are watercourses that are not part of a main river and include streams, ditches, drains, cuts, culverts, dykes, sluices, sewers (other than public sewers) and passages, through which water flows.

Hampshire County Council intends to work with riparian owners (those living adjacent to an ordinary watercourse) who are responsible for maintaining ordinary watercourses to ensure that the effectiveness of the existing ditches, particularly those adjacent to the A32, is improved and ensure that  future maintenance is undertaken at appropriate intervals.

See 'Reducing flood risk' guidance for further information.


Write to us at:

Flood and Water Management
Universal Services
The Castle
SO23 8UD