HVRA Drainage Improvement Group

The Dew Pond

Along the footpath between Valley Road and Boss Lane, in the field on the right is a concrete lined pond shaded by a pretty Weeping Ash (albeit leafless at present). Locals will know this as the Dew Pond, put there for the watering of livestock.

The origins of dew ponds lie in pre-history, but are generally regarded as shallow depressions in grazing areas traditionally lined with puddling clay or chalk and allowed to fill themselves from moisture in the air. In practice it is generally considered that traditional dew ponds are just as likely to be filled by water runoff from the fields and, of course, rainfall. Essentially, a dew pond is an artificial rather than a natural feature. Most have largely disappeared and replaced by piped water supply.

The pond on Boss Lane Farm is a concrete construct, a relatively modern method introduced in the early 1900’s, but clearly used on many farms and this one fits the standard profile. The pond is not filled these days and the original tree (see both pictures) is possibly suffering from old age and Ash die back.

In the early days it seems likely that being adjacent to the Hughenden Winterbourne Stream, when the stream flowed it would feed the pond as it still does today. At some point a water supply was laid to enable water to be pumped from two wells on the farm to fill the pond.

As it happens, the pond is just on a hundred years old, built by a former owner of Boss Lane Farm somewhere between 1918 and 1922. Two photos accompany this article, one recently taken and the other, grainy picture is believed to be from the early 1930’s.

So, is this a proper dew pond? Well, yes, it would certainly seem so despite being later updated to a pumped water supply. And it may be that the pond we see was created where an earlier dew pond sat. To make a feature of the pond it would require restoration involving re-lining and a new water supply, possibly from a borehole, which would be an expensive process.

Long may it live as a rather nice village feature.

Thanks to Matt Hopkins for his help in putting this together.

DIG Activities

The winter has been relatively kind to us this year – it has been generally mild, not too wet and while the Hughenden Stream continues to flow merrily through the park, it is dry in its upper reaches.

The DIG will meet in March to discuss plans by the utility companies affecting the Valley and to plan our activities for the year. Typical work we are looking to get done this year include:

• Fixing of puddling at the foot of Trees Road by TfB (In the budget, we understand)
• Surveying and clearance of culverts & drains at the pumping station site by Affinity (promised last year…)
• Continued work on monitoring and further lining of the Hughenden Sewer to prevent surface water ingress by Thames Water. (Apparently 139 metres along Warrendene Rd were lined last year).

Paul Woodford

Affinity

During September the DIG met with Chris King of Affinity to get agreement on surveying the drainage pipes under the pumping station. This was agreed to but we have had no further contact from Chris on the subject, we assume due to pressure of work.

To try and get something done on this we have issued a complaint to the Affinity Estate Management team and asked them to find out what will be done and when about this work. Fortunately, mild and relatively dry weather this winter has meant that the drainage there has not been tested.

Road Drainage

The DIG is planning on doing an audit on road drains through the Valley during February. As it happens it already looks as though TfB have carried out some drain cleaning already without any prompting, which is encouraging.

DIG 2022 Kick-start Meeting

After a relatively quiet few months, the DIG is planning to hold a meeting in late February as a starter for the New Year and to allow us to formulate some actions for 2022.

We have requested the Agencies to provide us with their plans and hope to be able to review those at the meeting.

Flooding Training

Although we don’t associate Hughenden Valley with being in a flood risk area, there have been plenty of occasions across the years when roads and properties have been tested by high water table, prolonged rain and so on. As such, the council, Environment Agency and other organisations monitor us for flood risk.

It can therefore make sense to at least be aware of how to deal with flooding when it happens. The DIG website contains some useful advice regarding flooding on the Advice page. On a practical front, Community Impact Bucks are offering free flooding training during March, for those with an interest in the subject. See below.

Community Impact Bucks are running free flood resilience training for local residents in HUGHENDEN VALLEY and RADNAGE on 8^TH March 2022 (2.30-4.30pm).

The training is open to anyone who would like to develop their community’s resilience to emergencies such as flooding, snow, other severe weather events or utilities failures. Attendees will find out what community resilience means and what it could look like, how to develop an action plan, and also how to apply for a grant from the Heart of Bucks’ Flood Recovery and Awareness Fund.which could be used for:

• Capital items to replace those destroyed by flooding
• Emergency repairs as a result of flood damage
• Venue/room hire costs for relocating activities as a result of flooding
• Community projects to prevent future flooding
• Training for flood damage/prevention

Although we don’t associate Hughenden Valley with being in a flood risk area, there have been plenty of occasions across the years when roads and properties have been tested by high water table, prolonged rain and so on. As such, the council, Environment Agency and other organisations monitor us for flood risk.

It can therefore make sense to at least be aware of how to deal with flooding when it happens. The DIG website contains some useful advice regarding flooding on the Advice page. On a practical front, Community Impact Bucks are offering free flooding training during March, for those with an interest in the subject. See below.

Community Impact Bucks are running free flood resilience training for local residents in HUGHENDEN VALLEY and RADNAGE on 8^TH March 2022 (2.30-4.30pm).

The training is open to anyone who would like to develop their community’s resilience to emergencies such as flooding, snow, other severe weather events or utilities failures. Attendees will find out what community resilience means and what it could look like, how to develop an action plan, and also how to apply for a grant from the Heart of Bucks’ Flood Recovery and Awareness Fund which could be used for:

• Capital items to replace those destroyed by flooding
• Emergency repairs as a result of flood damage
• Venue/room hire costs for relocating activities as a result of flooding
• Community projects to prevent future flooding
• Training for flood damage/prevention

For more information about the Hughenden Valley/ Radnage flood training and to book, visit https://communityimpactbucks.org.uk/event/flood-resilience-training-for-communities-hughenden-valley-radnage/

Pumping Station Ditches and Culverts

During September Jerry Morley and Paul Woodford met with Chris King of Affinity in connection with the drainage issue we have at the pumping station at Hughenden Valley. Chris is a Surveyor with responsibilities for maintenance of infrastructure at Affinity properties.

Chris has agreed to organise a complete site survey at the pumping station, which will involve CCTV checks and, if appropriate, clearance on the two principal culverts under the site which carry the Hughenden stream. It will also involve checking boundaries and cutting back of trees and hedges which have become overgrown.

As a group the DIG are not convinced that these two culverts have sufficient capacity to keep the stream flowing properly when it is in spate. We have seen at least one instance in the last few years of the water in the Valley Road ditch coming right up to the top and threatening to flood onto the road. A simple solution would be for TfB to continue the ditch right along in front of the pumping station so that it could then empty round the perimeter fence of the site into the National Trust field.

Sewer Works in the Valley

One of the biggest problems with the Hughenden Valley sewage system is the ingress of water into the system that typically happens over the winter period. This is common in the country and happens with old infrastructure.

Fractures in pipes and inspection pit brickwork allow ground water to enter the system, whilst road surface water can enter through leaky inspection pit covers. Thames Water have stated in the past that under normal conditions, the sewers in our area run at about 40% of capacity. During a wet winter we know from bitter experience this can exceed 100%, causing spillages.

In the last issue of the magazine, we mentioned that Thames Water was carrying out work on sealing the covers to the sewage inspection pits along Warrendene. Further work was done in the same area in relation to the possible re-lining of the sewer.

This work was of an investigatory nature and Thames Water are seeking to identify leaky areas in our sewage system so that a reactive leak reduction plan can be implemented.

Interestingly, the re-lining of sewage pipes is an established process which can have a major benefit to leaky sewers. Effectively, it is a structural ‘No-Dig’ repair which creates a new pipe within a damaged sewer. A resin impregnated liner is inverted into a defective pipe, it is then pressurised and then cured to form a new pipe. We hope this work comes to pass.

Paul Woodford