Sevenoaks strategic water main
Customer information pack
December 2018
Author: South East Water
South East Water Rocfort Road Snodland Kent ME6 5AH 0333 000 2244
Customer information pack | December 2018
Introduction
Dear customer,
Thank you very much for your interest in plans to lay a new water pipe in Sevenoaks.
This information pack contains copies of the information on display at the drop-in session and answers some frequently asked questions about our plans.
We hope we have been able to answer all your questions, but if you need more information or would like to provide feedback on the project, you can do so using the contact details at the end of this document.
As our plans progress, we will contact customers again through letters, the local councils and the press.
Our dedicated website page, corporate.southeastwater.co.uk/Sevenoaks will be kept up to date throughout the project and you can follow us on Facebook and Twitter @sewateruk for general news and updates.
Yours faithfully,
Ben McKellar Project Manager
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Customer information pack | December 2018
Project background
The existing 12-inch diameter cast iron water main, which runs through Sevenoaks High Street, is at full capacity.
Population growth means that parts of the town will have no drinking water or low tap water pressure every day during peak times (7am – 9am, 5pm – 7pm) within ten years.
There is also a risk the existing pipe could burst if it is pushed beyond its design limit.
We have already strengthened the water main feeding Sevenoaks directly from Cramptons Road Water Treatment Works along the A225 between the junctions with the A25 and Bradbourne Road.
We now need to lay a new pipeline from our Solefields treated water storage reservoir to the junction of Dartford Road and Avenue Road to ensure we can feed more water into the town to meet the daily demands during peak periods into the future.
Four route options are being investigated for the new main, all of which require us to connect the new pipe into the existing wider network in the A225. It is the installation of this new water main which we are consulting on.
We are consulting with a range of stakeholders, local interest groups and residents over the proposed routes.
Through our discussions, we hope to understand the impact each route would have and the factors which could help us to rule each option in or out.
When our consultation ends we will develop our final plans, taking all feedback into account along with a range of factors, including socio-economic, environmental, cost, duration of work, technical difficultly, traffic management required and more.
In a separate project, we are expanding the capacity of our Solefields storage reservoir to feed the growing population and reinforcing a 21 metre length of an eight-inch diameter water main along Tonbridge Road (near Sevenoaks School) to protect local water pressures when a new hotel is built in the town. This work is currently planned to take place in the school summer holidays of 2019.
We will write to affected customers about this separately.
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Customer information pack | December 2018
Route options
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Customer information pack | December 2018
Comparison of the key factors affecting each route
Knole Park and Sevenoaks School High Street East of Knole Park local roads and Knole Park
Cost (excluding £3.9 million £2.2 - £3.2 million £1.9 - £2.8 million £7.5 million compensation)
Pipe length 1.8 kilometres 3.9 kilometres 3.6 kilometres 9.5 kilometres
Work duration Up to 10 years Within one year Potentially two years Up to five years
Traffic Lane closures / Traffic lights on Traffic lights on A225, Road closures on Seal management road closures on A225, Hollybush Hollybush Close and Hollow Road, St Julians A225 Close and Avenue Avenue Road Road, Park Lane and Road Blackhall Lane. Traffic lights on A225.
Environmental Listed buildings. Within a SSSI but Within a SSSI but the Listed buildings and Potential the special special features will potential archaeology. archaeology. features will not be not be impacted by Partly within a SSSI but impacted by work. work. Potential special features won’t be Potential archaeology. impacted. archaeology.
Socio- Busy high street, Knole Park would Use of rugby pitches Increased congestion economic heavy commuter stay open maybe restricted at and pollution in other traffic, throughout, the school for one parts of town during road independent minimal disruption. year. Little impact on closures. Access to shops impacted Knole Park. various schools affected.
Technical Lots of other Ground Ground investigations A larger pipe and difficulty utilities in the investigations needed to confirm additional pumping ground to weave needed to confirm viability. stations needed due to the pipe around viability, however, the pipe length. we already have an 18 inch main in this part of the park
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Customer information pack | December 2018
High Street The proposed route is between Solefields Service Reservoir opposite Sevenoaks School and the junction of Dartford Road and Avenue Road via Tonbridge Road (A225), High Street and Dartford Road.
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Customer information pack | December 2018
Knole Park and local roads This proposed route is through Tonbridge Road (A225), Knole Park, underneath Seal Hollow Road then along Hollybush Close and Avenue Road.
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Customer information pack | December 2018
Sevenoaks School and Knole Park This proposed route is through Tonbridge Road (A225), Sevenoaks School and Knole Park, underneath Seal Hollow Road then along Hollybush Close and Avenue Road.
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Customer information pack | December 2018
East of Knole Park This proposed route would see the main laid south along Tonbridge Road (A225) from Solefields Service Reservoir, along St Julian Road, on to Park Lane, Back Lane, Blackhall Lane, along Seal Hollow Road, Vine Court Road and Avenue Road.
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Customer information pack | December 2018
Areas at risk of low pressure or no water due to development
2013
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Customer information pack | December 2018
Summer 2020
Risk of little to no water at times of peak demand
Risk of low pressure at times of peak demand
Pressures acceptable at times of peak demand
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Customer information pack | December 2018
Additional 600 properties at Sevenoaks Quarry site (in the Local Plan)
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Customer information pack | December 2018
FAQs
Where does Sevenoaks get its water from currently? A 12-inch diameter cast iron water main in Sevenoaks High Street takes water from Cramptons Road Water Treatment Works into town and to Solefields Reservoir. Once this new pipe is installed, we will supply water into Sevenoaks at peak times both directly from the treatment works and also from the reservoir. The existing 12-inch diameter main will stay in operation, and be supported by this new pipe.
How does the new pipe work to support water pressures in the town? Overnight, Cramptons Road Water Treatment Works pumps water to Solefields and Riverhill service reservoirs (underground, treated water storage tanks holding millions of litres). Then in daily peak demand we will use gravity to feed the town again. Pumps alone are not viable because there is a time delay and therefore cannot respond instantly to changes in demand.
If you don’t lay the pipe, when will Sevenoaks have low pressure/no water? Within ten years. We expect to supply all our customers with 15 metres pressure at the boundary valve but our legal minimum is 10 metres.
What are your legal obligations? We have the obligation to supply clean water to anyone who requests it at a reasonable pressure and to connect new developments to our water supply. Under Ofwat, we have the legal obligation to invest customers' money wisely and maintain an efficient water network.
Who gives you permission to lay new pipe? The Water Industry Act 1991 gives us permission to lay new pipelines in private land, however, we prefer to gain consent from the land owners.
The New Roads & Street Works Act gives us permission to lay in roads, however, Kent Highways can dictate conditions of our work, such as timings. Natural England give their Assent to our works that would affect environmentally protected areas.
Where does the money come from to lay new pipes? It is funded by bill payers, as set out in our five-yearly business plans which are approved by Ofwat. Our latest draft plan was published in September and is currently with Ofwat for review. We expect to hear the conclusion of Ofwat’s review in the New Year.
How large is the new water main (diameter)? 300 mm (12inches) in diameter. Water mains are usually laid around 90cm underground, depending on ground conditions, underneath all other utilities with the exception of sewers.
What engineering method(s) do you plan to use? We need to do ground investigations to find out what the soil is made of and its physical properties on each route option in order to choose a method, but generally speaking we use three techniques:
Horizontal Directional Drilling – We dig a series of pits around 100 metres apart, use a drilling rig to create a large enough tunnel underground which we can then pull the pipe through. This is a quicker way of installing long lengths of pipe with minimal disruption to the ground Page 13 of 16
Customer information pack | December 2018
surface, however can only be used within certain soil types, such as clay. It is also laid significantly deeper than other methods which can create maintenance issues.
Open-cut – We remove the top layer of ground, and if it is grassland or similar, we remove the topsoil and store it safely. Then, we use a machine to excavate a trench to create space for the pipe. This is a slower method but allows us to weave the pipe around other utilities in the ground and is ideal for hard ground conditions and archaeologically sensitive areas.
Trenching - A machine cuts a narrow trench through the ground. This is very quick but cuts through anything in its path including other utility pipes, cables and archaeology.
Where do you get information from on proposed developments? This is based on the current local plan and other proposed developments. Developers often come directly to us before they acquire a site. We are currently planning 60 years into the future to make sure we can meet future demand for water through new pipelines, reservoirs, reducing leaks and helping customers to be more water efficient. We review these plans every five years.
Do water companies comment on planning applications? No – we are not statutory consultees but have a legal obligation to connect new properties to our water mains. However, we do look at the local plans and plan 60 years into the future to make sure we can meet demand.
Who have you spoken to during your consultation? Sir Michael Fallon MP, Sevenoaks District Council, Sevenoaks Town Council, Seal Parish Council, Kent Highways, Sevenoaks School, Knole Park (Sackville Trust & National Trust), Lady Boswells School, Sevenoaks Society, Sevenoaks Rugby Club, Hollybush Residents Association, White Hart Residents Association.
How can people unable to attend the exhibitions comment? Those unable to attend our exhibitions can visit corporate.southeastwater.co.uk/Sevenoaks and fill in an online survey.
What is the deadline for comments to be considered in the consultation? The public consultation closes on 31 December 2018, but we will keep customers up to date as our plans progress. After our consultation closes, we will publish a summary of comments received during the consultation on our website.
How will you choose your final route? We need to take an objective look at the options and a decision will not be made until we’ve consulted everyone. We will assess each option and decide on a preferred route after we have heard all parties’ views as part of the consultation.
As part of this decision we will review the impact each route has on the local environment, social economics of the area, highways constraints, the cost of installation and the cost and ease of ongoing future maintenance.
When will a route be announced? We hope to choose a route in summer 2019, with work starting spring 2020.
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Customer information pack | December 2018
Next steps
Winter 2018/19 Public consultation session regarding route options.
Continued discussions with land owners, stakeholders and other local interest groups. Spring 2019 We will carry out further site investigations and develop our final plans taking all feedback into account along with a range of factors, including socio-economic, environmental, cost, duration of work, technical difficultly, traffic management required and more. Summer 2019 Further public engagement regarding the proposed route. Autumn/winter 2019 Customer and community communications begin advising of the final route and work programme. Spring 2020 Construction begins.
Give us your feedback
If you couldn’t attend one of our exhibitions or did not complete a feedback form on the day, you can also complete one online: surveymonkey.co.uk/r/sevenoakswater
You can contact us at any time using the details overleaf.
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Get in touch
South East Water Rocfort Road Snodland Kent ME6 5AH Tel: 0333 000 1100
Email our dedicated Customer Liaison Officer, Helen Tucker: [email protected] corporate.southeastwater.co.uk/Sevenoaks
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