Category Archives: DIG

DIG Article for HNews Winter Issue

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

DIG Report End September 2021

The transition of HVDIG into the HVRA is now complete. The final part was the closing down of the DIG email addresses, which means that we can now fully close down the old HVDIG website and email system run through TSOHOST. Email addresses for the DIG committee are now:

Peter Cannon: chairman@hughendenresidents.org

Paul Woodford: treasurer@hughendenresidents.org

Matt Hopkins: digdeputychair@hughendenresidents.org

Debs Lemon: digdeputysecretary@hughendenresidents.org

Sarah Mustapha: digsecretary@hughendenresidents.org

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.

Paul Woodford

DIG Report End July 2021

DIG AGM

The DIG AGM was held during July. The main points were that the accounts for 2020/2021 were audited and signed off by Bob Hawkins, the bank accounts is now closed and funds transferred to HVRA. In addition, the new constitution was approved and officers agreed to continue.

Drainage Issues

Trees Rd suffered from a heavy day’s rain with the road grills overflowing and a large amount of puddling at the foot. The Trees Rd team cleared the grills a day or two after.

We reviewed this with Jonathan Roberts the drainage engineer from Bucks CC. He will consider possible additional work, such as joining the grill soakaways to the road drains pipeage. Also he will look at the road surface & edging blocks at the foot of Trees Rd. This will not be priority work.

The DIG team also met with Jonathan to look at the drainage issue that we have at the corner of Boss Lane by the Hopkins field gate and which can lead to flooding of Boss Lane. There is an issue of drainage pipe sizing here plus some other problems. We have not been successful in making progress. Jonathan agreed to conduct some research  into historical survey data and also to look at possible solutions to our problem.

Paul Woodford

Drainage Works in the Valley

Thames Water are currently carrying out drainage works up in Warrendene Road for a serious amount of work. We understand that the sewage inspection pits in the road are being re-rendered around the tops and the lids will then be sealed.

The purpose of this is to prevent the entry of surface water into the sewage system, which contributes significantly to the overloading of the system in Hughenden Valley.

We understand this work will be carried out over several weeks and go right down Valley Road as well as Warrendene. There may be disruption to road users as parts of the sewage system in upper Valley Road run along the centre of the road.

DIG Report End April 2021

Sewer Status

Just when we all assumed that the sewer problems in the Valley had gone away, we found out that they haven’t. After the recent dry weather, inspection pit levels had pretty much returned to normal levels and it was largely assumed that the problems had gone away.

However, late in the month it was discovered that the ‘back of houses’ sewer run that is opposite the Village Hall was full and close to overflowing.  The Boss Lane sewer, which it joins, is also dangerously full. TW have visited a few times, but other than pumping out one resident’s inspection pit, have simply checked levels and advised there is little they can do. We keep monitoring.

Ditch Clearance

On the 10th April, the day of the Village litter pick, a small group of volunteers gathered by the pumping station for a general clear-up of the ditches and culverts there.

The culverting where the stream runs under Valley Road was in much need of clearance of leaves, twigs and assorted rubbish.

Fortunately the ditch along towards the Village Hall was in better shape, although the ditch itself is quite deep and difficult to access. Having said that, a couple of hours work has left the area in much better shape. It’s something that we plan to do regularly from now on, perhaps two or three times a year.

Road Drains

After pestering Transport for Bucks via the FixMyStreet website, we have at last had some serious work done on the road drains through the Valley from Church Farm up to the end of Warrendene Road. Hopefully they are all in good order now.

DIG Website

The HVDIG website is no longer being updated. Although still there, the Home page and Blog advise that the web site is no longer being updated and to go to http://www.hughendenresidents.org/dig. 

Paul Woodford

3 May 2021

Spotted in the Valley

After months of requesting the road drains to be jetted and cleaned, something seems to be happening. A team from TfB was spotted mid-week cleaning in Valley Road.

We hope the work continues because a recent audit by a DIG team found that roughly 70 of the 100 or so road drains from Church Farm up to the end of Warrendene were partially or totally blocked.

April Update

Audit of Drains

A small group of 4 within the DIG spent a busy couple of days in March carrying out an audit of the road drains from Church Farm right up through the village to the end of Warrendene Road. The result was that some 70 drains were blocked or partially blocked out of 100 or so. These were reported (individually) via the FixMyStreet website to TfB, and to their credit, the tops of all of them have been brushed since then. Actual cleaning/jetting may take a little longer – it’s only been a year so far.

DIG Website

The DIG website has been rebuilt and is now accessible from within the HVRA website, and adopts the same look and feel as the HVRA website. Take a look – it’s at www.hughendenresidents.org/dig although for the meanwhile the old website is still there at www.hvdig.org .

Status of Sewers

I think we can all breathe a sigh of relief in that the levels in our inspection pits have dropped and the risk of sewage escapes appear to be receding.

There have been two instances of the sewer junction at the corner of the pumping station leaking sewage, causing much consternation in the village. The DIG has written to Thames Water and requested for the inspection hatch to be replaced with a sealed lid. We wait to see if we get a positive answer.

Trees Road

We requested via FixMyStreet that the broken up road surface at the foot of Trees Rd be repaired as it was hazardous and leaving a semi-permanent pool of water there. This area has been quickly repaired, but it remains to be seen if the repair will prevent the pooling of water there – it’s meant to be able to run down the road to the nearest drain. We also need to speak with the water engineer to see if deeper soakaways are feasible there, as one of the soakaways completely overflowed in the last downpour.

Ditches & Culverts Group

We have set up a small group of volunteers for the ditches & stream area near the pumping station, as that is rather prone to accumulating rubbish. The first clean is planned for Saturday 10th April

We know also that for some years just one person has been looking after the ditch area opposite the Harrow, which is also prone to blocking up. It would be good to gather a few others to help out occasionally with that.

Agencies Update

Bucks Council have been successful in their bid regarding the Chilterns & Berkshire Downs Groundwater Resilience project. This means they will receive Defra funding for groundwater monitoring systems, which will include covering Hughenden Valley. A workshop will follow.

Thames Water has advised us that they are introducing a new planning system to replace their existing Drainage Strategy plans. (See the Little Marlow Drainage Strategy on the Documents page of the DIG website). The new planning system is referred to as a Groundwater Impacted System Management Plan (GISMP).

The GISMP’s focus is upon groundwater monitoring and the infiltration of groundwater into the sewage network. Where risk zones are identified it is planned to conduct fixes and improvement interventions within the normal maintenance cycle – presumably this means in the relative short term. Larger interventions will require budget and hence a longer cycle to resolve.

Sewage Leak at Corner of Pumping Station

On 17th February, a leak was spotted from the sewage inspection hatch at the corner of the pumping station site in the village. This hatch, which lies in the National Trust field (and hence open to all), is sited where the sewage pipe from Naphill comes down to join the main sewer heading to Wycombe.

The leak has tended to be intermittent and not a great flow, but nevertheless has been allowing sewage to get into the watercourse. The DIG alerted Thames Water on 18th and the site was visited by engineers, but they advised that the leak was due to hydraulic pressure and little could be done other than waiting for the pressure on the sewers to recede.

Since then we have alerted the Environment Agency, whose responsibility it is to monitor such leaks, plus the National Trust. The NT put up the signs towards the end of last week.

we are mailing the NT this week to suggest that they should consider putting further signs up in the park, where of course, dogs and children play in the waters.

Leaking Inspection Hatch

Article for Hughenden News Spring Edition

The Stream, Water Table and the Sewers

The winterbourne stream flows again this year in the village, and that makes it two years in a row, in itself a bit of a rarity. Although the stream dried up in the upper reaches last summer, it kept flowing all the way through from Church Farm. Since January, the source of the stream has gradually worked its way back up the Valley and through the village. At the time of writing, the stream is flowing from the ditch opposite the Harrow and down through the village. Strangely, it does not appear in the Hopkins Farm field alongside Valley Road, but re-emerges in Boss Lane.

The downside of having the stream up is that the water table is up in the Valley also. This applies particularly along Valley Road towards the pumping station. Here we know that the sewer main running to High Wycombe is currently full. In a wet winter such as this latest one, ground water and surface water infiltrate the system and overload it. The net result is the risk of sewage escapes, an unpleasant experience. Householders here are watching the situation closely and checking levels in their inspection pits. Thames Water is fully alerted to this situation and if it worsens we may need to call in temporary overpumping systems to help ease the pressure in the sewer main.

Trees Road & Trees Avenue

During the winter it was decided to try and build a small team to perform some self-help on the drainage grills at the foot of Trees Road. Both Trees Ave and Trees Road are un-made up and prone to clogging the drains and allowing water to sweep down onto Valley Road causing a few issues. A small team already existed cleaning the grills in Trees Ave.

The net result was a WhatsApp group of about 15 residents from both roads to perform periodic cleaning. The group go together on 24th January – a day of heavy snow you might recall – for the first clean. The job itself is not trivial, especially this first one, as the job had not been done on Trees Road for years. The team was led by David Mynors who showed the rest how to dismantle the grids and clear the drainage conduits. This was a great result, after two hours of hard work, with everyone wishing that a visit to the Harrow was possible.

Since then, TfB have visited after much badgering to perform a jetting & drain cleaning operation. They are needed to clear out the drains and pipework adjacent to the drainage grills. All we have to do now is persuade TfB that the rest of the road drains in Hughenden Valley need cleaning.

HVDIG Now Part Of HVRA

A special meeting of HVDIG took place at the end of January via Zoom and HVDIG is now part of the residents association and led by Peter Cannon, the Chairman. We are now called the HVRA Drainage Improvement Group.

As a first step, the HVDIG website has been altered to include the name changes and now incorporates the HVRA website banner/heading that emphasises the new identity. Further changes will take place over time, such as constitution and banking.