]> 2026-04-19T03:18:51+00:00 Case study:Harbertonford Flood Alleviation Scheme 500 en Environment Agency - 'Harnessing the Harbourne' Harbertonford News Integrating design with the environment to maximise benefits from a flood storage dam: successful implementation at Harbertonford. Approved Bed lowering Creation of pools and riffles Weir modification Channel widening River Restoration Centre Environment Agency Defra South Hams District Council & Harbertonford Parish Council Great Britain Defra South Hams District Council Harbertonford Parish Council No No Yes false CNV00014.JPG CNV00020.JPG CNV00007.JPG CNV00004.JPG View look upstream towards outlet of flood storage reservoir, with flow control structure. Courtesy of the River Restoration Centre. View looking downstream towards dam and outlet. Courtesy of the River Restoration Centre. One of a number of pool-riffle sequences installed on the advice of the River Restoration Centre. Courtesy of the River Restoration Centre. View from newly constructed flood wall in Harbertonford - looking downstream. Courtesy of the River Restoration Centre. No 50.390932489725,-3.7221557470855 NickRRC Nick River Restoration Centre Elbourne Bed lowering, Creation of pools and riffles, Weir modification,,Containment bund to prevent flooding, Construction of flood wall,,Channel widening, Surface drainage systems improved, SUDS,,,Engagement with schools, Community Education,, Surface drainage systems improved SUDS 1178 Environment Agency, Defra, South Hams District Council & Harbertonford Parish Council Illustration of proposed works. Courtesy of Bradley et al.(Available at http://www.britishdams.org/2004conf/papers/bradley.PDF). Harbertonford Project Works.png 1999 2451179.5 Complete The River Harbourne flows through the village of Harbertonford, which has been flooded on 21 separate occasions over the past 60 years - of which 6 flood events occurred between 1998 and 2000. The catchment is highly 'flashy', with little warning for residents prior to a flood. The Harbertonford Flood Alleviation Scheme was a joint project funded by DEFRA, the Environment Agency, South Hams District Council and Harbertonford Parish Council, costing £2.6 million. Its aim was to reduce the risk of flooding through the implementation of engineered flood alleviation solutions. A zoned clay-core embankment dam ('Palmer's Dam') with a 4.1 ha (150,000 cu m) reservoir storage area was constructed 2km upstream of Harbertonford, in conjunction with 600mm of bed level lowering and channel widening through Harbertonford to increase channel capacity (to accommodate flows up to 28 cumecs - 10 year flood. A flow control system was installed at the reservoir outlet to permit normal river flow, with automated flood control gates to throttle flows during a flood event. In addition, a flood defence wall was installed and surface drainage systems improved. Together, these measures were built to prevent flooding in Harbertonford up to a 1 in 40 year flood event. On 7th July 2012, a 1 in 40 year flood event occurred and Palmer's Dam was overtopped for the first time since its construction. This resulted in the flooding of some properties in Harbertonford, however flooding was limited to a few lowlying homes and the flood peak was significantly delayed, giving increased warning time. As part of the bed-lowering technique, a series of pool-riffle sequences were constructed within the channel through Harbertonford - a best practice approach for habitat enhancement, proposed by the River Restoration Centre (www.therrc.co.uk). These would provide both improved spawning habitat and habitat for adult fish. Works included: *Channel lowered by 600mm through Harbertonford using pool-riffle sequences, to increase channel capacity, to withstand 28 cumec flow (1:10 year event). Also widened in areas to further increase capacity. Two weirs lowered to minimise backwater effect (Crowdy Mill and Mill Leat). *Zoned clay-core embankment dam constructed 2km US of Harbertonford, with 4.1 ha flood storage reservoir (150, 000 cu. metre capacity), capable of withstanding up to 1:40 year event. *Flood wall installed along a portion of the river, through Harbertonford. Replaced earth bank. Surface drainage systems improved. Community Involvement - Local primary school visited site during construction of dam and have continued to visit 'reservoir' site, to study ecological development. Harbertonford Flood Alleviation Scheme harbertonford flood alleviation scheme Yes South Devon South West Containment bund to prevent flooding Construction of flood wall HARBOURNE RIVER harbourne river Harbourne at Harbertonford harbourne at harbertonford Engagement with schools Community Education Otter and common dormouse (protected); Atlantic salmon bullhead sea trout brown trout. 10 - 100 km² 375 200 - 500 m HARBOURNE RIVER GB108046005170 Flood risk management Social benefits 3500000 more than 10000 k€ Low Small Siliceous GB108046005170 Harbourne River 2002-09-01Z 2452518.5 2012-08-22T10:21:12Z 2456161.9313889 2019-01-02T15:11:00Z 2458486.1326389 Harbertonford Flood Alleviation Scheme 500 1 plainlist 5 [[Category:Case study]] [[Project title::!Harbertonford Flood Alleviation Scheme]] [[Subcatchment title::HARBOURNE RIVER]] Harbertonford Flood Alleviation Scheme# QUERY3bc3206cf8402347e4913888559440a7