Meeting documents
- Meeting of Services Overview Committee, Thursday, 13th June, 2019 6.30 pm (Item 100.)
To receive an update from Thames Water and other relevant representatives on flood prevention/matters and future challenges within the District.
Minutes:
Thames Water
Members
received a presentation from Thames Water representatives, Mr Huw Thomas, Local
and Regional Government Liaison Officer and Ms Dagmara Weatherall, Infrastructure
Planning Manager on the waste network arrangements and infrastructure in the
Chiltern District. The presentation covered the following and can be viewed
appended to these minutes:
- An overview of the Thames Valley sewerage network responsibilities.
- Drainage Strategies which had included detailed investigations
that helped with the understanding of drainage problems in Chalfont St
Peter (Maple Lodge) and Chesham and how they may be improved.
- An overview of the Maple Lodge sewer treatment works which
served a population of 495,000 and had a typical daily treated flow of
100,000 cubed metres, this could rise to in excess of 250,000 cubed metres
during wet periods.
- Proposed improvements including sewer repairs with watertight
lining; new monitors at some local sewage pumping stations to identify
when pumps are operating more than expected; groundwater levels being
monitored in the control centre with response teams informed if thresholds
passed; and to investigate if roof drainage can be separated from our
sewer network.
- How proposed local plan growth and other key growth challenges
in the region would be dealt with. Developers were being encouraged to
contact Thames Water in advance of submission of planning applications.
Customer relationship managers were proactively seeking out site
developers and working to meet developers, promoters and agents for large
development sites at an early stage of the planning process.
- Once a site identified as a risk to the wastewater network had
been approved for planning, an impact assessment would be undertaken to
identify if there was detriment to the network. Where certainty of growth
from other sites was also known then a strategic scheme would be
developed.
- Drainage and Wastewater Management Plans - these were the most
extensive, collaborative and forward-looking plans developed within the UK
wastewater industry to date. A framework was published in September 2018,
this consisted of Water and wastewater companies; Defra; Environment
Agency; Ofwat; Consumer Council for Water and; the National Infrastructure
Commission.
- Sustainable Drainage Systems (SuDS) which were an opportunity
to remove local impermeable area that would normally contribute to surface
water run-off. £150,000 would be made available to all boroughs in the
region for the installation of surface water management.
The Committee recorded its thanks to Mr
Thomas and Ms Weatherall for the presentation. Questions from Members were
welcomed, and the following key points were made:
It was affirmed to the Committee that
developers were being encouraged to make use of the free pre-planning enquiry
process, following which they would receive a letter outlining whether there
was sufficient capacity in the existing network or whether investment was
needed. Thames Water was consulted on and made recommendations to the local
Planning authority on all significant developments.
Impact assessments would be completed
once planning approval for developments had been completed. When these had
concluded it would be known how large the solution would need to be and whether
existing networks could handle the additional flow.
A statement of common ground agreement
was formalised as part of the Chiltern and South Bucks Local Plan, this was
signed by Thames Water, Chiltern and South Bucks District Councils and the
Environment Agency.
Following a Member comment, it was
confirmed that installations which assisted collection of rainwater, avoiding
heavy flow into the sewer network such as water butts could often result in a
refund to the consumer. This rebate was due to less surface water being dealt
with from individual properties. Members suggested that this could be marketed
further to make consumers aware.
In relation to the £150,000 investment
to local authorities to deal with surface water run-off, it was clarified that
this had been set aside for authorities as they were now, meaning that each of
the five existing Councils in Buckinghamshire would be entitled to a separate
fund of £150,000 with the transition to a unitary authority not having an
impact on this.
A Member raised a concern that the
sewer which ran through the Misbourne valley from Amersham to Chalfont St Giles
appeared to have leakage and asked whether this had been addressed. It was
confirmed that the sewer had been investigated and the findings would be
reported back to Members. It was understood that the pipes were relatively old
and were not sealed the same way as water mains would be.
There were 14 mobile pumping station
units strategically placed across the Thames Valley and these were not fixed to
individual locations. The units would be moved as and where needed.
Affinity
Water
Members
received a presentation from Dr Di Hammond on revitalising chalk rivers in the district.
The presentation included the following and can be viewed appended to these
minutes:
·
The
reasons behind the Revitalising Chalk Rivers initiative, these included being
more visible and working together to promote the great river restoration work being
completed.
·
River
habitats and functional feeding groups as well as the effect of restoration on
LIFE scores.
·
Catchment
changes which may affect the river including dredging and straightening of the
river channel; land drainage and loss of wetlands and; urbanisation.
·
Potential
benefits of river restoration such as improved fish passage; increased aquatic
plant diversity; natural flood risk management; water quality improvement;
health and wellbeing and mitigation for climate change.
·
Examples
of river restoration work completed in recent years and potential projects at
River Misbourne sites including Barn Meadow, the Community Orchard site and
Amersham to Quarrendon Mill. An outline design was displayed for the Amersham
to Quarrendon Mill river path.
·
The
“#whynotwater†campaign which called for government to act on mandatory water
efficiency labelling so consumers could make informed choices on appliances
purchased; rights for tenants to request landlords install water saving
measures; ensure fixtures and fittings met minimum standards to avoid wasting
water and every Local Plan in a severely water stressed area should include the
target of 110 litres per person per day.
The Committee recorded its thanks to Dr
Hammond for the comprehensive presentation. Questions from Members were
welcomed, and the following was clarified to the Committee:
It was confirmed that the plan was for
work to commence on the River Misbourne toward the end of 2019. A Member highlighted the importance of being
mindful when dredging not to destroy the lining of a river as this could
prevent the river from filling. It was confirmed that Affinity would plan to
dig any new channels close to groundwater, maintaining inflow. The aim was to
make the river more natural and resilient to river droughts.
Buckinghamshire
County Council
Mr Alex Back, Senior Strategic Flood
Management Officer, Buckinghamshire County Council clarified the
responsibilities of each agency and reported an update on an ongoing project to
increase flood resistance measures for properties in surrounding areas of
culverts. This included measures such as electrics being wired high up,
appliances being kept above flood level and solid wood floors. These resilience
measures would reduce the time people need to spend out of their properties.
Businesses were also an area of focus to ensure that the impact from flooding
would not keep them closed for a significant period. The County Council was a
statutory consultee on all major planning applications and the lead local flood
authority who had a statutory duty to investigate any kind of flooding.
Environment
Agency
Members
received a presentation from Ms Natasha Gibbs, Technical Advisor on the two
main rivers running through the district, the Chess and the Misbourne and the
flood alerts and warnings which were in place.
The flood
warnings were established based on full modelling being completed following the
wider flooding of the River Misbourne in 2013/14. The Environment Agency was
working closely with Affinity on the restoration of chalk streams and was also
working on ensuring that the HS2 project did not have a significant impact on
the Misbourne.
All options
for improving the Misbourne had been deemed economically unviable at present as
the Environment Agency had been unable to secure funding. It was hoped that the
programme would be explored again post 2021 when grant aid and the flood risk
settlement had been agreed.
Further work was being undertaken to
engage riparian landowners to ensure assets and river banks were adequately
maintained to reduce flood risks and meetings were being held with partners to
address maintenance. Should any Member wish to know the grade of a culvert at
any given time there was an asset mapping online service (link included below)
which they could use.
The
Environment Agency continued to monitor ground water levels to predict
implications on the Misbourne network. Culvert inspection took place every 5
years as per T98 inspection. It was said that a Grade 4 culvert was deemed
‘poor’ and would likely see an increased number of inspections. Grade 5
culverts required immediate attention.
A Member asked what needed to be done
where severe water loss could be seen and was advised that there was an
incident hotline (noted below) and members were encouraged to report all
expected issues, whether these were on private land or not so that these could
be inspected.
Members raised the Culvert at the
Maltings, Amersham as a concern, this culvert was graded as a 5 and it was
advised that this would be checked by the Environment Agency prior to any
expected heavy rainfall. Members were encouraged to forward any concerns to the
EA.
The useful links and contact
information are as follows:
The online asset map which detailed all
assets the Environment Agency holds information.
https://environment.data.gov.uk/asset-management/index.html
The May 2019 water situation report
which contained information around the Chilterns Chalk levels was also
available online at https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/807680/Hertfordshire_and_North_London_Water_Situation_Report_May_2019.pdf
HNLenquiries@environment-agency.gov.uk
- e-mail address to be used for information around certain assets or
watercourses.
PSO-Thames@environment-agency.gov.uk
- e-mail address to be used to provide information around works near a river.
The webpage to visit beforehand for further information was https://www.gov.uk/guidance/flood-risk-activities-environmental-permits
The incident hotline: Telephone 0800 80
70 60 https://www.gov.uk/report-an-environmental-incident
The Chairman thanked Ms Gibbs for her
detailed presentation.