What's the challenge?
Dawlish Brook, also known as Dawlish Water, begins its journey at Haldon and runs through Ashcombe valley, before reaching the sea at Dawlish Beach. On its journey it drops over weirs and under bridges, passing through the Manor Gardens and the Lawn, eventually joining the sea on the eastern side of the main sea wall, passing under the railway viaduct. The Lawn is a focal point for visitors and local residents alike and is home to many species of duck and several black swans.
The Brook has been altered over the years for various reasons and this has had an effect on the flow characteristics. Of late, the frequency and unpredictable nature of recent severe weather conditions has led to flooding, which has affected nearby properties and businesses.
As well as the greater rainfall events, another underlying issue is the sediment run-off from the catchment further inland, which, because of the weirs, settles in the Brook. Annual expensive dredging would only deal with this symptom in the short-term and not tackle the root cause of the problem.
Also, when the flows in The Brook increase there is a likelihood of the sediment being carried down to the beach area. The sediment carries various substances that could affect bathing water quality at the beach, which is measured by the Environment Agency. Therefore, this is another reason to investigate ways of reducing sediment run-off entering The Brook.
During the bathing season, which runs from the 1st May until the 30th September, the bathing water is sampled by the Environment Agency every 7 to10 days. Results of the weekly sampling results can be found under the 'Related Pages' heading to the right of this page.
Reducing the impact of contamination and pollution of bathing waters in the UK is an essential piece of work that local authorities, landowners and the Environment Agency are undertaking. Locally, this includes the works being proposed at Dawlish.
If you would like to know more, the Environment Agency has a really useful website which is worth a visit, please see the link under 'Further Information'.
And the solution?
Unfortunately, there's no easy solution although we are working hard to reduce the risk. Areas in the lower reaches of the Brook are in a designated flood zone and only expensive flood defences, which may include major redesigns of the Lawn and town centre, could be considered. However, problems with the Brook could be tackled at source (upstream), using an engineering solution developed in partnership with the Environment Agency and Dawlish Town Council. If sediment transfer from the catchment into the lower reaches of Dawlish Water can be identified and managed, this will reduce deposit rates and will have a positive effect on the town, the Brook and the beach.
In January 2013 the Environment Agency completed a survey around Dawlish Water and Ashcombe. They noted actual and potential inputs of sediment further away from the river. This included gullies and landslips alongside the highway.
The Environment Agency contacted 32 land holdings and will undertake a walkover study for the Dawlish Water catchment, to identify and record any sources of sediment, which may later settle and accumulate in the channelled section in the town. When a sediment source is located, the Agency will take photos and record what they have found. They will then visit the land owner concerned to explain the issues and discuss possible solutions.
In the meantime, Council engineers will complete a detailed survey of the lower section of Dawlish Water, from the viaduct to Barton Hill, to establish the hydraulic characteristics of this critical section. A further survey of the upper section, from Barton Hill to Church Street, will also be undertaken and this information will help assess the flows and performance of the weirs and sluices in the river.
Pollution and bathing water quality
Freshwater streams and rivers flowing through different landscapes, rural or urban, can enter the coast close to bathing water. Waste entering rivers from discharge pipes (point sources) or run off from land (diffuse sources) can be contaminated with animal and human faecal waste. Depending on the number of discharges and type of land use, levels of faecal contaminants in freshwater can be extremely high, especially following wet weather. Typically when freshwaters enters the sea, massive dilution occurs and levels of faecal contaminants are highly reduced in the bathing water.
Teignbridge District Council, Dawlish Town Council and the Environment Agency will also start to explore funding sources for any projects to help alleviate the problems.
Dawlish Town Council, Teignbridge District Council and the Environment Agency intend to hold a public event to let everyone know about the findings of the study and to highlight possible options.
The Council will formulate a business case with Dawlish Town Council and the Dawlish Water Working Group. This will help develop the improvement, enhancement and regeneration options for Dawlish Water.
Dawlish Town Council have also agreed to fix ladders to the slopes of the weir and sluice gates to allow the swans and other ornamental birds to move in the watercourse. They also intend to repair the nesting sites and prepare landing stages to help the swans leave the water.
- The Environment Agency - http://www.environment-agency.gov.uk/
- The Environment Agency Twitter updates - https://twitter.com/EnvAgency
- Dawlish Town Council - http://www.dawlish.gov.uk/
- Watercourse maintenance - http://www.environment-agency.gov.uk/research/policy/31740.aspx
- Sediment transport & alluvial resistance in rivers - Report 2008 - http://cdn.environment-agency.gov.uk/scho0608body-e-e.pdf
- Bathing water quality - http://www.environment-agency.gov.uk/homeandleisure/recreation/142937.aspx
- Bathing Water Quality