Starcross: Flooding and the Community
This paper is a working document, last updated November 2015
Why should Starcross take an interest in Flooding?
Rising Sea Levels
Sea levels have been rising since the last Ice Age – on average 2mm per year. Over the last two decades this has increased to about 3mm per year, due to rising sea temperatures and the melting of ice sheets such as those in Antarctica and Greenland. It is anticipated that over the next 25 years sea levels locally could rise by a further 10cms, and in the following 25 years by a further 20cms. Another factor which will affect sea levels in the estuary is the management of the sand spit at Dawlish Warren. Maintaining the sand spit as a defence against flooding is potentially very expensive – recent years have seen significant erosion of the sand dunes, exposure of the gabions and undermining of the groynes - but allowing it to follow a more natural course, and potentially to breach, as has happened every 30 – 40 years in past centuries, would result in high tides in the estuary rising by a further 10cms on average, and wave heights during storms by 30cms.
Increased Frequency of Extreme Weather Events
It is also expected that rising sea temperatures will lead to a 10% increase in the severity and frequency of storms. This also increases the probability of flooding in low lying coastal areas.
What are the implications of this for Starcross?
Tidal Flooding. Most of the village, including the residential areas in the centre of the village, lies up to 1 metre below the level of the highest spring tides. Starcross is already dependent upon the railway embankment for protection against tidal flooding at high spring tides several times per year. Rising sea levels and increasing frequency of storms may mean that our current sea defences become no longer adequate to provide good protection against flooding. The Environment Agency advises that without further action to sustain and improve flood defences locally, including the railway line, the risk of significant flooding in the village will increase from a 1 in 50 chance in any year, as it is at present, to an almost certainty of flooding at least once a year by the end of the century. The slipways running under the railway embankment at Generals Lane, at the Fishing and Cruising Club, and near the junction of the A379 with Estuary Road by Exeleigh are identified as potentially weak points through which flooding could occur, as well as Cockwood Harbour. The first week of February 2014 brought significant flooding of roads and some homes as tidal waters overtopped the Estuary Road slipway, and also the railway line at its lowest point just north of the station platform in Starcross..
Rainfall and Run-off Flooding. As events in November and December 2012 demonstrated, Starcross is also vulnerable to flooding during periods of extended, heavy rainfall. The land slopes back westwards from The Strand to form a natural shallow basin into which water running off the fields behind will drain, and collect. Three lanes leading into the village from the West act as conduits for run off from the fields; three water courses (Staplake Brook, and springs rising near Tiverlands Farm and to the north west of Starcross) also make their way through the village; without active water management this can result in floods in the lower land behind The Strand. On the night of 24th November 2012 floods occurred at the bottom of Brickyard Lane, also the car park and the cul de sac leading to New Road from Brickyard Lane, and New Road itself; also the bottom of Staplake Road west of the junction with The Strand. The flooding affected properties in Parkers Road, Brickyard Lane, The Strand, and New Road near the Cockwood junction. Increasing frequency and severity of extreme weather conditions increase the likelihood of such floods.
Why does Starcross need to be involved?
A considerable number of agencies are already involved in planning against the risk of flooding in our area. The Environment Agency, alongside partners including the Exe Estuary Management Partnership, Devon County Council, and Teignbridge District Council, are developing the Exe Estuary Flood and Coastal Erosion Risk Management Strategy. The strategy will identify areas that are at increasing risk of flooding, and also options for the management of that risk. These include a range of possibilities, from improved flood defences in some areas, to managed realignment in others, and the maintenance of important natural habitats. Members of the Parish Council are already actively involved in the Exe Estuary Management Partnership, which is contributing to the Risk Management Strategy. This ensures that we are kept well informed, and that our views are heard and represented.
Given that a number of relatively large and powerful agencies are already involved in flood prevention work in the Exe Estuary, the question could be asked as to why Starcross should need to take an active interest in water management and flood prevention.
The answer to this question is that a local flood plan would have a different focus from that of the Risk Management Strategy. The Risk Management Strategy focusses primarily on capital expenditure projects which will be needed in coming years to protect our community from flooding due to rising sea levels. The primary focus of the local involvement would be to ensure that the drainage and protection systems we already have in place are working as well as possible, to minimise the risk of avoidable floods.
The need for a local flood prevention plan to ensure that our drainage systems are well maintained and working properly is heightened by the complex nature of responsibility and ownership of different parts of the system. Over a short stretch of half a mile or so, a water course through the village may fall within the remit of several different landowners, Devon County Council Highways, Teignbridge, South West Water and Network Rail. With frequent reorganisations, transfers of responsibility between agencies, and staff changes over the years it can be seen that records of responsibility, and awareness of the need for regular maintenance could be lost, and there is evidence that this has contributed to our experience of flooding.
It is also clear that by the time flood conditions prevail and the waters start to rise it is far too late to start worrying about drains which are blocked, and systems which need maintenance. Our experiences in November 2012 showed that by the time we needed to ask the emergency services for help, much of the rest of the county was already in far deeper water, and the services were at full stretch elsewhere, and unable to get to us very quickly. Also, it is easier and safer to undertake necessary and routine maintenance work during daylight hours, in dry conditions and with the streams at low level than it is to undertake clearing a blockage in an emergency, in the dark, in very slippery conditions, and with half a field full of water waiting to rush through as soon as the blockage is cleared.
The village of Starcross itself is best placed to have an overview of the situation. Maintaining up to date records of who is responsible for each part of water management, and also a schedule of when each regular maintenance task becomes due will help us to improve our flood resilience, and reduce the risk of experiencing avoidable floods due to blocked drains and the failure of flood defences.
This will help to protect us in the shorter term, while capital projects are is progress, and will then work alongside the Risk Management Strategy to ensure that the systems continue to work well.
The Benefits of a Flood Resilience Plan
In summary then, the benefits of a local flood plan are as follows:
The first and most important benefit is preventing avoidable floods, and damage to property.
The second is that planned maintenance is safer and easier and more manageable for the responsible agencies than emergency responses.
The third is that it will allow for better co-operation between agencies, and better co-ordination of interdependent activities.
Ancillary benefits could include secure home insurance premiums, community involvement, and a tidier village.
Who are the Stakeholders in the Starcross Flood Resilience Plan?
The Residents and Local Businesses of Starcross
Local Landowners and Land Holders
Starcross Parish Council
Teignbridge District Council
Devon County Council Highways
South West Water
Network Rail
Environment Agency
Teign Housing
Tasks
1.To develop and maintain as complete as possible an understanding of how the surface water management systems in the village work, and where the risks are.
2. To get to know as far as possible all the points at which water passes underneath the railway line into the Estuary, and where all the non-return valves are situated.
3. To identify all other points at which water can potentially flow into the village from the Estuary, and cause flooding, such as the slipways.
4. To work with the partner agencies to develop a program of regular maintenance which is needed to keep the systems working well.
5. To get all the relevant partner agencies to agree to the Flood Resilience Plan, and to sign up to their responsibilities within it.
What We Know Already About Water Management
The Railway Line
The railway embankment is Starcross’s main, and very effective, defence against flooding from the estuary. Network Rail holds responsibility for ensuring that the sea wall and railway embankment are in a good state of repair.
Slipways
/ Generals Lane Slipway is managed and maintained by Teignbridge District Council. There are flood gates in place, which are managed by Teignbridge District Council. At spring tides TDC arranges for the gates to be closed./ Starcross Fishing and Cruising Club Slipway is managed by the SFCC. The top of the slipway is higher than either of the other slipways. There are no flood gates in place at present. No flooding to property has occurred at this location in recent years, but the crown of the slipway was overtopped by the tide on the night of February 4th 2014.
/ Estuary Road Slipway
The slipway at the corner of the A379 and Estuary Road is the responsibility of Network Rail. Flooding from the estuary has occurred at this location, with water flowing through the slipway opening and across the road to pool at the corner of the A379.
Water Courses
Staplake Brook runs down the valley to the south of the main village, next to the B3381, Mamhead Road. It then passes through a culvert under New Road, before crossing Oak Meadow Golf Course and flowing out into the estuary through a culvert leading under the A379 and the railway line. To the west of Starcross, in the region of boreholes which supply water to the village, the watercourse is maintained by South West Water. Further east along its course, responsibility is held by the landowners. The landowner of the field next to New Road is aware of the need to maintain a clear watercourse, and also to ensure that the entrance to the culvert is kept clear, to minimise the risk of flooding in New Road. He is also willing in principle to sign up to the flood resilience plan.
Responsibility for the watercourse through Oak Meadow Golf Course is held by the landholder, who is also aware of the need to maintain a clear watercourse, and is willing in principle to sign up to the flood resilience plan.
Water flow through the culvert leading under the road and railway line from the Golf Course to the estuary is managed by holding ponds/ditches on the inland side, and tidal valves in the culvert. The tidal valves close as the tide comes in, and the water pressure on the outside exceeds the water pressure from the stream on the inside. This prevents water from the estuary entering through the culvert and flooding the area of the golf course and road which is below high tide level. During the tidal period when the valve is closed, water accumulates in the stream bed, in the deep ditches running alongside the cycle path, and in overflow onto the golf course.
As the tide goes out, water pressure on the land side pushes the tidal flap open, and water drains out into the estuary. This arrangement has proved adequate in protecting property in Generals Lane from flooding from Staplake Brook so far. However, there is potential for increasing the capacity of holding ponds on the golf course, if it were needed, subject to the agreement of landowners, and planning consent.
Responsibility for maintaining the culvert is held by Network Rail and Devon County Council Highways. Work has been carried out within the last five years to repair the culvert. The entrance to the culvert is monitored by the landholder, who alerts Network Rail in the event of any problem.
Springs Rising to the West of Stile Farm, and the West of Staplake Mount flow into the field to the south west of the junction of the A379 with Estuary Road at the northern end of the village. The stream then flows through a culvert under the A379, The Strand car park and the railway line into the estuary. Low lying parts of the field act as a holding pond at high tide when the non-return valve is closed and water cannot drain away. Work has recently been carried out to clear the watercourse and improve drainage. The landholder of the field holds responsibility for the watercourse through the field up to the entrance to the culvert, and is aware of the need to maintain a clear watercourse. Teignbridge District Council inspects the entrance to the culvert monthly and clears the grill as needed.
Network Rail holds responsibility for the maintenance of the pipe under the railway. This was surveyed in 2011 and found to be in good condition.
There are non-return valves under a manhole cover in the car park, and in a chamber on the foreshore next to the railway wall. Teignbridge District Council acknowledges responsibility for the culvert under the road, and for the non-return valves, and has recently (October 2013) undertaken work to ensure that all is in good working order.