Claire and Charlie Gooch
Proposal for a Natural Swimming Pond
Brief
To convert the existing pond (approx. 600 sq.m.) at Fen Farm into a natural swimming pond, utlizing the existing shape and size.
Concept
A swimming pond is a self contained ecosystem in its own right that uses plants, gravel, water aeration and circulation to maintain water clarity.
The proposal is to create a swimming zone of 25m length by 8m wide and 1.6m deep. This will comprise approx 30% of the entire pond. The rest of the pond will be used as the regeneration zone for a variety of aquatic plants (predominantly native species) to naturally filter and clean the pool to keep the water clear, and to create a pleasing, colourful aesthetic throughout the swimming season.
In line with the route from the house, the edge of the pond will require a wooden deck (approx. 4m by 3m, plus steps into the water) to allow easy access into the swimming zone and be an attractive space to sit on chairs and enjoy the view. This deck will sit above the 3m regeneration zone on that side of the pond.
Outline Construction
In a nutshell, Eau Naturelle will create a sealed unit, to keep the naturally cleansed pond water in and any surface water run-off from beyond the pond, out. The swimming pond is, essentially, a self-contained eco-system.
To control the water level, an overflow extraction system will be built in, and drain out to the ditch.
Due to the proximity of the two oak trees to the waters edge, some of the earth within the pond will need to be used to build a buffer between the trees and the pond liners. These will be semi-circular and need to be built out approximately 2m to 3m, dependent on any root structures that become visible when the pond is drained and during initial excavation.
The willow tree will need to be removed to minimise leaf fall into the water. Also, in approximately the location of the removed willow, a second wooden pontoon (which could be used by anyone wishing to dive into the swim zone) is required in order to facilitate the concealed installation of a second skimmer, and further boost water circulation. A swim zone of this scale (half Olympic in length) requires this additional skimmer to the one concealed under the main 3m x 3m seating deck.
Due to potential issues with the high water table, the sub-swim zone will require a drainage system to prevent the rising water before it becomes a problem pushing up against the liners. This is simply an 'over dig' beneath the swim zone, filled with gravel and water extraction pipes buried within the gravel, and exiting to the sump (replacing the existing overflow drain) and then pumped out to the ditch.
Once the entire pond has been sculpted and the sub-pond drainage system installed, we lay the under-liner, followed by the waterproof membrane, followed by the over-liner (everywhere except the swim zone). The over- and under-liners protect both sides of the waterproof membrane which is guaranteed by Firestone for 20 years. All liners reach right out and over the wooden brace that circles the pond, forming the outer edge of the regeneration zone. Outside this is the French drain - that completes the outer circle of the pond - topped in 40mm gravel - that is designed to keep any external water ingress from happening, and the piping that collects the water in the French drain exits via the same route as the sub-pond drainage system.
When the liners are all down, we build the sandbag wall around the swim zone. The sandbags are a natural looking dark olive green colour and will be built to a height of 1.2m. We then commence filling the swimming zone with mains water, through a special filter system that extracts 99% of the phosphates in the water.
We then fill the regeneration zone - behind the sandbag wall - with 20mm gravel up to 50% of the gravel's eventual depth, and install the circulation piping and the aeration piping within it. The gravel slopes at a gentle gradient upwards from the sandbag wall to the outside edge of the pond. We then lay another sheet of under-liner over the entire regeneration zone, before topping up the pond with the remaining 50% of the gravel, now mixed with pre-washed sand. The point of this extra sheet of over-liner is to keep the roots of the aquatic plants at the top level and to stop the sand seeping down.
The gradient allows for the appropriate variations in depth that different plants require. Deep water at the swim zone edge is, for example, perfect for water lillies, while shallower water is ideal for other species.
On the garden side of the French drain (which is topped with 400mm gravel), we will install a metal EverEdge border that sits flush with the grass edge to give a crisp outline and makes the pond border easy to mow. This grass border, unlike today, will no longer be damp.
Before the water reaches the final level, we complete the installation of the aeration system (and pump) and complete the installation of the two skimmers. All are important for circulating the water and providing a healthy eco-system. The skimmers remove surface water debris without negatively impacting wildlife, whilst the aeration system injects 6 bubble spouts into the swim zone to assist in circulating the water and aerating it.
Once the water level reaches the desired height, we plant the aquatics.
Aquatic Plants
Below are a selection of recommended plants for your pond, providing a lengthy flowering period from March to October, but with the majority from May to September.
Roll your mouse over each image for the name and flowering period.
May - Sept
Mar - May
May - July
Aug - Sept
July - Sept
May - June
June - Sept
June - July
Aug - Oct
In order to maintain the sense of scale of the existing pond, planting will focus on low growing aquatics on the side nearest the house. This will, therefore, comprise mostly of white flowering water lilies, repeated again on the far side of the swimming zone in order to extend the 'clear' view to well beyond the half way point - to at least 20m from house-side edge. Taller plants, such as the reeds - Sweet Gallingale (90cm) and Flowering Rush (60-90cm) - will be positioned on the far side of the pond (as viewed from the house).
The proposed colour scheme is whites, blues, pinks, purples, flamingo greens and tall, lush green reeds.
Construction Sequence Detail
Items marked with * are your responsibility, although we will advise and oversee.
We also itemise the number of days required for each part of the job. WL-J and SP days on site are charged at £250, whilst other labourers - sourced through you or us - are estimated at £150 per day (but hopefully less).
Number of WL-J or SP days are the first mentioned below, whilst other labourers are included in the 2nd or 3rd listing. For example: 2 x 2 days is WL-J for 2 days plus gofer for 2 days.
Drain pond and allow to dry (allow 30 days)*
Re-route pond filling system to ditch*
Dig pond to specified design*
Dig trench for electric cable*
Electrician, cabling, terminals*
Dig sump*
Dig trench for sump extraction pipe to ditch*
Dig trench for sub-pond drainage pipe to sump*
Remove willow tree and dig out roots*
(Allow 7 days for the above with WL-J on site for 3)
Lay sub-pond drainage pipe
Install paving slab for base of sump
Install sump pump and connect to drainage and extraction pipes
Install sump cap
Back-fill pool trench to sump*
Install overflow system
Back fill overflow trench, French drain outlet and trench to ditch*
Install wooden perimeter between pond and French drain
Cap wooden perimeter with protective insulation
(Allow 4 days for the above + 1)
Pour gravel into sub-pond drainage area and level off (3 x 1 day)
Install underlay (2 x 2 days)
Install Firestone membrane (3 x 4 days)
Install overlay (2 x 1 day)
Build 2 layers of sandbag wall, install skimmer return pipes at 45 degrees (3 x 1 day)
Build sandbag wall to lie flush with base of regen zone (3 x 2 days)
Install aeration points (6 of) (2 x 1 day)
Complete building sandbag wall (3 x 2 days)
Commence filling pond with water
Install regen zone pipes (2 x 0.5 days)
Pour first layer of gravel in regen zone - raking towards centre (2 x 3 days)
Lay second level of overlay (2 x 1 day)
Pour second level of gravel / sand mix (3 x 2 days)
Trim liners and membrane into French drain, install French drain pipe (2 x 2 days)
Fill French drain with gravel and level off (3 x 1 day)
Install skimmers / pumps, lay aeration pump slab, complete installation of aeration pump (2 x 1 day)
Install wooden deck and steps (TBC)
Install wooden pontoon and steps (TBC)
Plant aquatics (2 x 2 days)
Install EverEdge between French drain and lawn (3 x 3 days)
Test all systems (1 day)
From completion of the initial dig to the end of the project: allow 7 weeks
Total cost of all labour: £15,650
Quotation
Thank you for inviting Eau Naturelle to quote for assisting in the design and construction of your natural
swimming pool. As agreed, everything will be done at cost, with all invoicing going through you to keep everything transparent and above board.
Design and technical drawings for your approval prior to commencement £750 + vat (allows one revision)
All materials and aquatic plants £36,100 + vat
Labour £15,650
Miscellaneous: allow £5,000 + vat for excavation problems, weather delays, surprises
Maximum Price: £57,500
Recommended first phase, if you are comfortable with quotation: commission design and technical drawings
for approval (above price includes one revision to both drawings)
Price Excludes
Digger, digger man, dumper and earth removal
Electrician and cabling costs
Decking / Pontoon (this is only exluded at the moment as we need further discussion with you regarding
type of wood; it can then be priced up once you approve the design drawings)
Telehandler, Mini-digger, Whacker Plate
Note
We have priced pre-washed gravel at £29.45 per ton delivered. Total: 251 tons.
We have priced pre-washed sand at £17.70 per ton x 60 tons.
You can probably get it for much less and please feel free to do so.
Terms & Conditions
Due to the nature of our arrangement whereby everything is being done at cost, should you decide to proceed,
it is agreed that:
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You will be responsible for paying invoices swiftly upon receipt, in the knowledge that any delays in payment may result in unexpected delays and project / cost over-runs.
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You will designate appropriate hard standing areas for delivery and provide all necessary equipment for moving deliveries (sand, sandbags, gravel etc.) to pond site.
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You will be responsbile for any necessary insurance for those working on site.
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With the exception of WL-J and SP, labourers on site may need to be paid daily or weekly and you agree to make such payments, subject to receipt of itemised time sheets. WL-J and SP will invoice for time to date mid-project and then again at completion.
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You will kindly allow us to photograph the project at all stages for use on our website, and allow us to publish copies of the designs too.
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You will kindly allow us use your swimming pond as an occasional show pond to demonstrate our work to prospective clients. We will attend in all cases without the need for your involvement, and will always pre-agree appointment times with you.
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You will not disclose to any third parties the costings for your project and not disclose that Eau Naturelle did the work for you at cost. In fact, you may wish to tell your friends that a project of this scale, if done by an established company, would cost approximately £200,000. But for any of your friends, Eau Naturelle can probably do it for half that price. Eau yes!
Maintenance
A swimming pond needs much less maintenance than a conventional pool, as there are no chemicals to add and manage. Nature carries out almost all of the cleaning services for you, but it is still needs a small amount of regular attention. Namely, emptying the skimmers and ensuring that leaves do not build up in large quantities.
Removing leaves (and discouraging ducks) helps to keep the water's nutrient levels low. On this basis we can guarantee the water to be completely clear all the time. Many people like to spend time looking after their pond themselves. However we also have a dedicated maintenance team and offer a maintenance service which can be as often or infrequent as you need. We generally recommend that our maintenance team visits at least once a year to check on the pond's development and its equipment, assist in trimming the acquatic plants, and to give the swimming zone a hoover.
Eau Naturelle charge £250 for call outs and for up to half a day (4 hours) and £400 per day for maintenance services.
