Agenda item

Environmental Improvements to the River Gade

Presentations by the Environment Agency


JDoe introduced the report and invited Christopher Hall from the Environment Agency and Kieran Sheenan to make their presentation.

Christopher Hall thanked the committee and gave some background to the River Gade improvements. The key points were:

He said that the members would probably want to know why the Environment Agency were proposing it. He explained that the main driver for the project from the Environmental Agencies point of view was the Water Framework Directive, which since leaving the EU has been adopted into UK law. The river Gade was failing on a number of measures set out by the Water Framework Directive and was in a less than good status. Part of their commitment to the water quality of the River Gade. The proposal was to realign the river channel which would revitalise the chalk stream to what it used to be.

A large amount of water resources capital and water resources revenue funding had been secured from the Environment Agency in 2021 and 2022 and around £400,000 and a further £250,000 from 2022/2023 onwards from Affinity water, as Affinity is part of their revitalising rivers partnership.

The main objects of the projects were to improve the river and the adjacent parkland, creating an environment more akin to the natural chalk stream. This would improve opportunities for amenity and recreation around the river, improve resilience to low flow events and to climate change by reconnecting the river with the groundwater table. It would improve the ecology of the river by creating an environment that supports good ecological status under the water improvement regulations 2017. It would also improve the floodplain by re directing the river to the valley bottom and would also address the impact of the gauging station, which was currently in Gadebridge Park and acts as a barrier to fish, by its relocation. There would be a reduction in the maintenance of the current channel by improving flow and therefore cutting down on the growth of vegetation.

The overall cost is estimated to be around £750,000. They have around £610,000 of water resources capital money overall and as previously mentioned they have money from Affinity Water.

The project also meets DEFRA’s 25 year environment plan and the outcomes would be pure clean rivers and resilient water supply, beautiful landscapes, flourishing wildlife and native species, thriving rural economies and communities, protecting animals and plants from health risks. The project also supports Dacorum Borough Council’s policies, including the Local plan 104, supporting initiatives to improve the quality of the water in rivers and canals part C. Part D, encouraging wetland habitat creation, part F restoring culverted watercourses to a more natural state and also Local plan CS26 and the strengthening of biodiversity corridors, the better public access and links through green spaces and finally CS27 (the conservation of heritage assets) and the NPPF paragraph to identify and address the particular significance of any heritage asset that may be affected by a proposal.

So the main benefits anticipated would be that 57% Framework Waterbody Directive would be enhanced with 415 meters of river restored. 1.1kilometers of waterbody opened up to fish and eel passage, 6.5 kilometres of river habitat enhanced and 0.3 hectares of wetland habitat created. The project would also improve water sustainability, contribute to the delivery of the water land and biodiversity. It would also impact on consideration of abstraction reductions and changing the land use.

Delivery of this project is estimated to cost £750,000, which would include a 60% optimism bias. The amenity aspects of the budget were estimated at £120,000 and they Dacorum Borough Council has been asked to make a contribution to the amenity aspect. Therefore the whole project cost would be around £870,000. They were currently at the point of almost completing their modelling and creating detailed designs on where they expect the river to go and the bridges to be placed. The project was expected to commence in September 2021 and be complete in 2022. However, due to Covid, the dates were slipping. If agreement for the funding was obtained from the committee this evening, they could come up with a project plan that would be acceptable for everyone.

Kieran Sheenan shared slides outlining the proposed changes and took questions from the committee.

Cllr Beauchamp asked, assuming the project goes ahead and the river is moved, and given that the run off from the Leighton Buzzard road runs at various points into the existing perched channel and will no doubt continue to do so once it’s moved, who would be responsible for the maintenance. He said he was aware of a project taken on by Affinity Water at Gadebridge Lane, but who will ensure there is a good flow throughout and that it does not become silted. He also asked if they could give assurance in continuity of supply not just in the park, but as it joins the Water Gardens and the Riverside development. Finally he questioned how much they had spent on consultancy so far.

C.Hall responded that the responsibility, once they have completed the project, would be handed over to Dacorum Borough Council as it is currently DBC’s responsibility. However part of the project plan is that it would decrease the need for maintenance.

K.Sheenen said they are doing another study on the channel retaining water and he would be able to report back then.

A.P KSheenan to provide information on the further study

Cllr Birnie asked if there were any indication when he could report back

KSheenan said they were looking at next month.

Cllr Beauchamp asked if they had a date on when the project was likely to be initiated as the dates have moved over the years, and whether the Bowls club would be involved at every step.

KSheenan confirmed that currently they were looking approximately next spring and the Bowls club would be involved.

Cllr Timmis referred to the new bridge that was pictured and contrasted it with the White Bridge,which is very attractive, whereas the one they had pictured was more like a road bridge, rather modern and not in keeping with the chalk stream. She welcomed what they were planning for the River Gade, but there were two other chalk streams in Dacorum and wondered whether there were any plan in respect of those two streams.

KSheenan said they were in partnership with other agencies in regards to the other streams. In relation to the bridge he confirmed it was not a road bridge, the idea was that it would be a 3 meter wide bridge not designed to take traffic but designed so people can cross at diagonals, it was a wide design so as not to feel constrained and it would have a low gradient so that wheelchairs can go over. The design allows for lattice work across the parapet that would look like the White Bridge.

Cllr Birnie commented that it would have to go through the planning process.

JDoe confirmed that the whole scheme would have to go through planning with particular attention paid to the bridge, not so much because of the White Bridge itself but the site was very close to the Bury which was a listed building and any structure may well affect its setting and that would be subject to discussions with the conservation officer.

Cllr Wyatt Lowe said that they had heard a lot about the structural changes that they were proposing which would enhance the flow of the chalk stream itself.However she hadn’t heard anything about how they were going to improve the water quality as she understood that one of the issues with chalk streams was the discharges into them and they should be doing something about the water quality itself at the same time and she would like reassurance on this point.

KSheenan responded that water quality was not in the brief they were given. However, what they were going to do was capture the discharges from the Leighton Buzzard road and bury them on the existing line of the Gade, take them down and discharge them into the flood culverts which was where they were discharged anyway. They currently discharge into the river and then discharge into the flood culvert. Other discharges in the town are caught by the spring flow culvert including the ones from the Queensway carpark. He quoted a phrase “ The solution to pollution is dilution” which means they effectively put a small amount of pollution into a larger volume of water which is not perfect, but that said the river Gade itself should be cleaner. A major issue with the Gade is the fine sediment that was a pollutant in itself, as it added phosphates and nitrates to the water that causes turbidity which is bad for fish, microorganisms and for photosynthesising plants. It was also bad for the fish reds as the silt fills them up. One of the reasons they were keeping the river flowing cleaner and flowing more rapidly was that it would reduce the amount of fine sediment and that will help dramatically with the water quality. Other unseen pollutants are on the WFD requirements and the targets for the river and those are being dealt with the by the Environment Agency. Most of the point source pollutions in the UK had been dealt with, but 95% of the issue that they have UK wide is diffuse pollution. This covers things like misconnections and also agricultural runoff and pesticides and such pollution was very hard to pin down. There were larger schemes running nationwide run by Natural England in terms of greener farming. However, in terms of the solution to pollution being dilution, if they put more water in the watercourse any pollution that they do have will be diluted. One of the things that was being done by Affinity Water as a result of pressure from the Environment Agency is a reduction in the abstractions taken from the rivers, so all of that should help.

Cllr Stevens asked for assurance that the abstraction they have here was now at its peak and that they were now able to rely on the water flow to be able to keep the river flowing.

C.Hall said that the Environment Agency deal with the licences for abstraction. However he couldn’t give a definitive answer at the moment but would come back on the point.

A.P CHall to come back to the members on the licences for abstraction

Cllr England stated that from what he understood, they were not going to take the runoff water out of the water. He said he did not have much confidence in the scheme they had outlined and that it was going to take a lot of the pollution away from the river. He asked if they could be sure that, in scoping out a new channel, a large amount of the river flow would not simply go down into the course gravels which were as he understood just below the surface across the valley floor, and also how would they know where the so called original channel should be, or was it that they were not going back to roman times and were just choosing a suitable modern course for the river.

K.Sheenan responded that they were not trying to go back to the original course and he had explained that in his presentation, it would be almost impossible to say where the original course would have been as so much has been done over the ages to change it. Many view rivers in a different way to what they actually are. They imagine that river had been a single thread winding down the centre of the valley and never changing. But the chances are that it was either a wandering channel that changed course regularly or a braided channel that splits and re-joins. It all depends on the gradient and the amount of gravel in the river at that moment. What they did know was that it would have been at the bottom of the valley as the river cut the valley, but the current position was entirely man made. They would not try to recreate the original channel but try to create something that was more natural and the benefit of that would be water flowing through clean gravels leading to a reduction of silt coming into the river and depositing on the margins and destroying any reds for the fish. It would require a lot less intervention that the system that is currently there. In terms of the loss of water through the gravels, that could be an issue and they are studying that at the moment. Depending on the results of that study, they may well take a slightly different route.

Cllr England asked whether the project was wortwhile as it did not effectively address pollution problems and also asked for confirmation that they have overestimated the costs by 60% just in case something goes wrong. 

C.Hall agreed that they have overestimated what the price may be to be sure that the cost would not go any higher.

Cllr England noted that the large bridge seemed partly designed to accommodate the gauge to measure the flow and asked if that would be the part that Dacorum Borough Council were being asked to pay for.

K.Sheenan said that there would be 2 bridges. The one near the Bowls Club was part of the scheme and the Environment Agency were paying for that, but there would be another bridge further up the park, north of the Queensway car park and that would be the one that Dacorum Borough Council would be paying for. In relation to his previous question, the river was not currently meeting various Water Framework Directive targets that is was supposed to meet because of; fine sediment, lack of fish connectivity, abstraction problems and the gauging station coming to the end of its life. This meant there were not really any do nothing options.

C.Hall said that something would eventually have to be done. The water that does not go through their gauging flume is missed by the hygrometry and telemetry people and would therefore affect any flood warnings for Hemel so they do need an accurate gauging station in Gadebridge Park and they do not have one at the moment. The existing one was probably built in the 50’s or 60’s and will be coming to the end of its life very soon and something would have to replace it.

Cllr England said he had seen a lot of pictures of the River Gade from around 50 years ago and it appeared much wider. He felt the solution would be to have a new gauge and more flow in the river by taking less water out of the ground further up so that it could flow in the river.

K.Sheenan said he wouldn’t disagree with him but people in London want their water and this water extraction was an issue with population levels.

Cllr Harden said he was intrigued by the examples given of the flooding. He asked whether increasing the height of the banks of the river, as opposed to re-routing the river, would solve the problem. He was also intrigued by the sense that re-directing it for a more natural flow would resolve the flooding problem and wondered what the difference in costs would be and would it be cheaper to raise the banks of the current river, and would any of this resolve the flooding north of the white bridge

C.Hall gave as an example context on how the Environment Agency measures flood risk the flooding in the Somerset levels in 2013/2014. That was a one in 200 year event, but they expect with climate change that these events would become more frequent.

K.Sheenan said that it seemed counter intuitive, but if they put the river at the bottom of the valley it could drain the whole valley. If they keep the river where it is at the moment it is perched so that all the water that comes down doesn’t get into the river, so it is missed by the gauge so they don’t know how much water is actually going down. It drains away into the gravels. In terms of building up the banks, they have been doing that in Yorkshire since time immemorial and yet Hebdon Bridge gets flooded every year and the place is full of walls. It doesn’t work in the long term. He said that currently the perched channel has no way for the fish to get into it, so it failed on that score, it has fine sediment so it fails on that and the reason it for that was because it has no gradient because originally it was a mill lake to retain the height of the river along the edge of the valley to drop down at the head into the existing channel water wheel. So it is perched above the natural level and no matter how high you have those walls it would always have that low gradient and consequently you were always going to have fine sediment issues and extra maintenance costs. So raising the banks is a simply a short term solution. With climate change more sudden flooding events are expected as the air will contain more water vapour, leading to larger winter storms with heavier rain.

Cllr Birnie said that raising the banks would preclude the promised features that were educational for children.

K.Sheenan agreed.

Cllr Harden asked if the redesign of the river would stop the flooding north of the river.

K.Sheenan said that it wouldn’t.

Cllr Birnie asked whether amenities such as the beaches and the bridge would not be provided if DBC does not put in the money requested.

C.Hall said that they would not get the footpaths and one of the bridges. The Environment Agency would be paying for the large bridge by the Bowls Club as that would house the new gauging station. The Council’s contribution would be for footpaths, the second bridge and some information boards.

Cllr Birnie noted that the report mentioned a number of springs coming into the river and asked whether they simply comprised run off from the car parks and the Leighton Buzzard Road, or were there some natural springs that still exist and run usefully into the river.

K.Sheenan said that were some natural springs.


Cllr England agreed with Cllr Rogers that there were more studies to be reported and it would make sense to him to hear them before they gave their approval and support. He would suggest that they delay supporting it now and ask that a clearer case was put forward.

Cllr Wyatt-Lowe agreed in that they were still tweaking the project and that they had to go back and take more measurements and soundings. She agreed with a project that should in principle be an improvement however she felt that that case had not been proven tonight and she would prefer to wait until the plans that were being put forward were more defined than those that were presented.

Cllr Birnie asked whether the funds that were already raised were time limited and would a delay in the project affect the availability of those funds.

C.Hall said that they put in a bid each year from the working capital revenue budget but each year they have been successful and they were confident that they would continue to get funding.

Cllr Birnie asked if he could fully answer the funding question and come back to us with the number of other points they were taking away that evening.

A.P C.Hall to provide more information about the funding

Cllr Harden said he was trying to look at the potential risks if the project was not to go ahead and that it did not give him an answer. The issue he had was trying to still be wise with taxpayer’s money and wanting to improve something within the natural environment and that was the challenge he had in his head. He asked if they chose not to invest as a council what would then happen. They had been told that the river would get more polluted and there would be worse flooding but was that it, was it the natural scenario of the river that was going to happen? If that was the case then what would the Environment Agency’s responsibilities be and would how they deal with that be affected if the local authority does not invest?

C.Hall responded that if the council does not invest then the Environment Agency could build a project where there would be one bridge missing but there would still be the rest of the project. It would be nice if the council did contribute, however the bulk of funding was coming from the Environment Agency and Affinity Water. As for the “what would happen” the water quality is failing the WFD so they had a legal responsibility to do something to it. They have looked at other options but they feel that the channel realignment was the best one. If they were to do nothing then eventually the gauging station and the flume down the left hand side of the park would need to be replaced because of the flooding in other parts of the park. When the existing gauging station becomes useless, they would miss a lot of the flow and they would not be able to give accurate flood warnings for Hemel Hempstead Town Centre. There would also be more flooding affecting the Bowls Club leaving areas of the park unusable over winter months and the spring water would not be picked up.

Cllr Beauchamp said in its current form he couldn’t support the project, there were far too many unknowns. However he looks forward to a plan that suits all of the objectives that they have. They need to spend more time on this.

Cllr Silwal agreed with Cllr Harden in that they have already spent £130k in feasibility study, investigating and outline design so if they were to hold back on the project that would be a waste. They need to think about it.

J.Doe followed up on some of the points that were made by the members, he thought it would be fair to say that there would be more work required on this as Cabinet has to receive a report in due course to make a final decision on whether the scheme could go ahead because it runs across Borough Council land and indeed the question of the Borough Council’s contribution.

Cllr Birnie suggested in view in the opposition around the room that they welcome the report and hoped that Cabinet would continue to engage with the Environment Agency, without making any recommendation as to whether it should be taken forward.

Members agreed.

Cllr Rogers asked if we should be voting on it

Cllr Birnie a vote was not necessary

Cllr Rogers continued that they had heard from both sides of the argument and rather than just going ahead with it, there seems to be a bit of dissent in the room.

Cllr Birne explained that they were simply noting and welcoming the report. He assumed that nobody could object to their welcoming information. The committee was simply suggesting that cabinet continue to look into the project by getting more information from the Environment Agency.

Cllr Rogers said as he understood this would go forward to Cabinet and they could give the go ahead and yet they have heard many reservations about it.

Cllr Birnie confirmed it would go to Cabinet without a positive recommendation to proceed. The Committee could only make recommendations and Cabinet could choose to ignore recommendations if they wished. In any case, it would have to go to Full Council if there were a certain expenditure involved. However as there were some reservations expressed, he would be very surprised if it did not come back to this OSC meeting in due course.

Cllr Rogers suggested to ensure that was the case that they say that they recommend that it doesn’t go forward that Cabinet does not make a positive decision to go ahead with the project.

Cllr Birne said they have not made that recommendation either way.

Cllr Rogers asked if they could make that recommendation.

Cllr Silwal said that the Officer’s report recommendation was to consider and give support to the river restoration scheme within Gadebridge Park and Members to express their views.

Cllr Rogers said that he would propose that they and suggest to Cabinet that they have great reservations and they do not believe that it would be a positive step forward without sufficient information.

Cllr Wyatt-Lowe seconded that proposal

Recommendation; the Committee recommends that Cabinet do not to move forward with the plans in their current state without further information.


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