One of several teenagers seen crossing the Wealdstone Brook recently - if they fell in the water they could swallow something very nasty
A comprehensive objection has been submitted on the Brent Planning Portal to the Lidding Road Garages Planning Application. The Planning Committee will consider the application next week (Wednesday April 20th) after its deferral to consider a report from Thames Water.
Planning Officers are recommending approval LINK .
Comments can still be made on the Planning Application HERE
LIDDING ROAD GARAGES PLANNING
APPLICATION number 21/3248 APRIL 2022
The Wealdstone Brook is a river that
starts from a spring on Stanmore Common in Harrow and runs through Harrow, into
Brent near Woodcock Park in Kenton and then onto the river Brent beyond
Wembley. By the time water enters the London Borough of Brent at the cross roads of Kenton
Road and Kenton Lane it is already seriously polluted and reading counts taken
of the E.coli bacteria in the water at the end of Lidding Road in Kenton, were
one of the highest recorded from waterways in the London area. E.coli is a
naturally occurring bacterium that is found in the human gut and is therefore
an indicator of foul raw sewage in a water course.
This serious level of water pollution
is due in part to known and unknown misconnections of the foul surface water
and foul raw sewage water connections throughout its course through Harrow and
the additional misconnections in this part of Kenton, Brent. Under severe
rainfall events the Wealdstone Brook quickly fills to its maximum capacity before it reaches Woodcock Park and, due
in part to poor maintenance, blocked and damaged foul surface water and foul
sewage drains, the areas around the Brook quickly get flooded and badly
polluted. The most recent recorded foul raw sewage overspill was from the
manhole on the grass area at the end of Lidding Road on the 5th October 2021. This raw foul sewage
over spilled onto the grass area, onto the area next to it known as the Legion
Hall site and then into the Wealdstone Brook.
The Wealdstone Brook was an earth
bank water course and there are numerous recorded flooding events between 1927
and 1981. In 1977 on the 16th and
17th August the Brook
burst its banks and the whole surrounding area of Kenton was flooded including
numerous residential properties. Following this 1977 event, works were
undertaken along the length of the Brook up to and including the junction of
the Kenton Road/Kenton Lane interchange – in other words mainly on the Brent
side. These works included the widening, deepening and brick-walling sections
of the Brook from Woodcock Park down to Wembley. The aim of these improvement
works was to increase the capacity of the Brook and to speed up the flow of the
water. An engineer’s report at that time indicated that these improvements
would alleviate problems of flooding for 50 years – and that was 43 years ago.
The Wealdstone Brook is simply
incapable of coping with the expected water run-off during storm events because
it is, according to a recent Thames Water engineer, attempting to operate at
over 130% capacity during severe weather events. There is an important
difference between the Wealdstone Brook over-spilling its banks and the
flooding which occurs around the Wealdstone Brook during severe weather events.
This distinction is important in the light of the recorded history of the
Brook. As stated earlier, the Brook starts its life from a spring on Stanmore
Common in Harrow and continues to receive surface water from several sources as
it runs towards the river Brent:
1. Surface road drains taking rain water from roads and into the
Brook. Most of the outlets of these drains can be seen on the sides of the
Brook and most are at a low level where their outlet enters the Brook. Many are
blocked with debris due to poor maintenance and soon become unable to discharge
when the flowing water level in the Brook rises.
2. Water run-off from saturated ground – such as the parks, school
grounds as well as gardens which abut the sides of the Brook.
3. Damaged, broken and leaking clean water drains.
4. Misconnected foul sewage water and surface water pipes which
connect to the surface water drains as in 1).
5. Springs
Even in the driest of summers and the
coldest of winters, water continues to flow in the Brook.
It is when there are torrential
downpours and storm like conditions that we see the full force of the Brook.
Within 30minutes of a storm event in the NW London area, the Brook can be full
of water moving along it at a rate of 20 tons per second. In these situations
the Brook is at full capacity when it hits the culvert that runs under the
Kenton Road/Kenton Lane interchange and the roads around here become flooded.
The poorly maintained road drains cannot cope and cannot discharge into the
Brook. By the time the water reaches the Falcon Way culvert it is also full to
capacity. Again, road flooding around this area and around Lindsay Drive
roundabout occurs for the same reasons. These are all HA3 0 areas of Kenton. If
any problems occur further down the Brook such as blockages of the road and railway
culverts or the opening of the sluice gates on the Welsh Harp, then the flow of
water in the Brook is slowed resulting in areas around the Brook higher up
flooding even more severely.
Flooding from the Wealdstone Brook is
therefore a more complex issue than simply saying that the Brook is overflowing
its banks. It is a combination of hydrology issues which vary from event to
event and include such factors as the direction of the weather storm event, the
intensity of the downpours, the length of the downpours and, crucially to begin
with, the state of the drains. Once a storm event has started both surface foul
water and domestic foul water sewer drains quickly become full, house drains
overflow and the mixture of these waters pollutes the surrounding land and
intensifies the pollution of the Brook.
The main Wealdstone Trunk Sewer,
which follows a similar path to the Wealdstone Brook through Woodcock Park and
onto the northern section of the grounds of Uxendon Manor School, has been
known to discharge its contents from 6m underground to well over 3m above
ground during severe storm conditions. All this foul and surface water attempts
to flow into the Brook.
To put it bluntly, the drainage
infrastructure in the area simply cannot cope and is not fit for purpose. For
the Environment Agency and Thames Water to say that housing developments close
to the Brook can tap into the present infrastructure is to ignore the numerous
occasions that Thames Water and Lanes for Drains have had to clean, repair and
replace various pieces of drainage pipework in the area in the past few years.
And to attempt to build on and next to the present drainage infrastructure as
suggested in the Lidding Road garages development proposal (Planning
Application 21/3248) would land Brent Council with a substantial structural and
economic ongoing problem which would be both a disaster for the residents of
these new builds, the residents in the surrounding area as well as an ongoing
and increasing economic burden for the Council tax payers of Brent Council.
Hash Patel, a past Principal Engineer, Transportation Service with Brent
Council, following flooding around the Brook on Wednesday 26th August 2015 and Wednesday 16th September 2015 stated the following:
“Regarding the River Brent and
Wealdstone Brook, I am not aware that surface water has topped the banks (of
the Brook). I am aware of flooding in your catchment and majority is related to
inadequate capacity in the public sewer network” (my emphasis)
Thames Water knows it has to divert
the damaged, broken and dysfunctional Victorian sewer pipe that runs from
Woodgrange Close, through Woodcock Park, across the green field sites at the
end of Lidding Road, through the back gardens of numbers 9 to 14 Brookfield
Crescent and onto the manhole junction in Brookfield Crescent, before any works
can take place on the site of the old Legion Hall and the grass area at the end
of Lidding Road. This would be a very expensive piece of restructuring work.
Best not to let them pass the buck to Brent Council.
It is wrong to consider housing
developments in a flood plain zone 3 area and it is wrong to build over foul
water sewers and surface water sewers. The Environment Agency and Thames Water
are wrong to approve to the proposed housing development at the end of Lidding
Road (Planning Application 21/3248). They are, in my opinion, acting
irresponsibly.
Brent Council declared a Climate
Emergency in 2019 (www.brent.gov.uk/climateemergency)
and their pamphlet ‘Nature, green space and the climate and ecological
emergency’ should surely be the foundation and driving force in the local
Planning agenda. ‘Protect the remaining green spaces, support biodiversity,
stop flooding or reduce their severity by preventing surface run off’ – all
good intentions which need to be put into practice.
An Independent London Flood Review has been announced (Wednesday 22nd December 2021) into the flooding
events of July 2021. The review seeks ‘to better understand the extent and
causes of these floods, to assess how the drainage systems performed, and to
recommend how the increasing risks of future flooding events can be managed.’
‘The review, which has been
commissioned by Thames Water, will play an integral part in ensuring that the
company future proofs its infrastructure to protect its customers, their
communities and the environment as such severe weather events look set to
become the norm across the UK.’
‘The review will also play an
important role in improving the collaborative working between all parties
responsible for managing future flooding risks. As part of its focus, the
review will provide insights on London’s wider drainage infrastructure and
broader recommendations that could be adopted by all organisations with surface
water responsibilities. It is anticipated that the review will take no more
than 6 months with interim reports published as it progresses.’
It would be prudent of Brent Council
Planning Committee to await the findings of this review in areas where flooding
has occurred and is occurring not just in severe weather events but under
normal rainfall conditions. This should be particularly applied to areas
designated as Flood Zones 3a and 3b by the Environment Agency such as in the
Lidding Road garages Planning Application 21/3248.
‘This Independent Review will also
assist with Thames Water’s role (as a Risk Management Authority) in supporting
Local Authorities in undertaking their flooding investigations as required by
Section 19 of the Flood and Water Management Act (2010).’
‘As part of its Independent Review
this inquiry will examine the flooding mechanisms and consider the performance
of drainage systems against design standards.’
This will hopefully set a standard
whereby Brent Council Planning Officers and Brent Council Planning Committee
members can assess whether a housing development such as that proposed at the
end of Lidding Road meets the necessary flood risk assessment standards or is
too risky to consider until major changes have been undertaken to the surface
water and foul sewage water drainage infrastructure in the area of the proposed
development.
Finally, I would like to conclude on
the assumed role of the Environment Agency (EA) with regards to the Wealdstone
Brook and its maintenance including its banks. The EA claim in an email letter
to John Poole dated 28th April
2021 that they do not own the Brook and are not responsible for its maintenance
including the banks of the Brook. The EA claim the maintenance is the
responsibility of the riparian owner where the banks are owned by the landowner
which in the case of my garden would be me. There is just one problem with this
approach to the responsibility for maintenance and repair and that is that the
EA does not allow me to enter the Brook to carry out any necessary maintenance
or repair. The other issue to do with this denial of responsibility from the EA
and delegation of responsibility to riparian owners is that Brent Council would
have to take over stretches of the Wealdstone Brook and its banks where Brent
Council owned land joins the Brook or where the Council owned properties with
gardens end at the Brook since they would be designated the riparian owner.
This is particularly relevant in the case of the Planning Application 21/3248
since Brent Council would be deemed to be responsible for the maintenance and
repair of the Brook and its banks from the footbridge near the Woodcock Park
Mural, through Woodcock Park, past the end of Lidding Road, past the site of
the ex-Legion Hall grounds and down to the Falcon Way bridge at least on the
Uxendon Manor School side of the Brook. Needless to say, if this was proven to
be correct this would have very serious financial implications for Brent
Council.
References:
BRENT COUNCIL – Flood Risk Management
Strategy – Managing the Floods Risk in Brent - 2015
GREATER LONDON COUNCIL – Public
Services and Safety Committee Report (30.09.77) – from the Director of Public
Health Engineering - Flooding on 17th August 1977.
MINISTRY OF AGRICULTURE, FISHERIES
AND FOOD – Departmental Investigation into Flood Warning Arrangements in North
West London – Report – (25th April
1978)
GREATER LONDON COUNCIL – RIVER BRENT
FLOOD ALEVIATION SCHEME – ENGINEERS REPORT – MAY 1982 –WEALDSTONE BROOK.
HALCROW REPORT – The Environment
Agency Thames Region – Wealdstone Brook Investigations – Scheme No 3721 –
February 1999
ENVIRONMENT AGENCY OPERATION AND
MAINTENANCE MANUAL FOR RIVER BRENT FLOOD ALLEVIATION SCHEME – WEALDSTONE BROOK
VOLUME 3 (Contract no.BD3) LEDWAY DRIVE TO KENTON ROAD – January 2002.
WATER FLOW RATE (m3/s) READINGS OF
THE WEALDSTONE BROOK FROM THE UNIT AT THE JUNCTION OF KENTON LANE AND KENTON
ROAD – from 30TH November
1976 to 14th November
2020 DURING SEVERE WEATHER EVENTS.
SUSTAINABLE DRAINAGE SYSTEMS: WRITTEN
STATEMENT-HCWS161 made by Eric Pickles (Secretary of State of Communities and
Local Government) – 18th December
2014.
NOTES FROM THE KENTON DRAINAGE
MEETING HELD ON WEDNESDAY 12TH OCTOBER
2016
Water Industry Act 1991 – Chapter 56
– Sewerage Services – as amended.
Wealdstone Brook Water Quality
meeting Thursday 22nd August
2019 which includes a map of all the misconnections of foul sewage water pipes
and surfaces water pipes known at that point in time in the Harrow area.
THAMES WATER – Building over or close
to a public sewer – undated but updated on a regular basis on the Thames Water
website.
PINNACLE CONSULTING ENGINEERS –
PROBABILITY OF FLOODING – A flood risk assessment revision 1 as part of the
Planning Application for temporary classrooms on the Uxendon Manor School site
– undated but probably around 2015 and includes a detailed Thames Water
Drainage and Water Enquiry of the area around the school.
Flood Risk Assessment – Uxendon Manor
Temporary Classrooms – April 2015 – Price and Myers – contains important
information with regards to flood risk assessment in the area of the proposed
Lidding Road development.
Email correspondence with Hash Patel,
Principal Engineer, Transportation Services, Brent Council September 16th 2015.
London Flood Review (https://londonfloodreview.co.uk/)
December 2021
Environment Agency email from
Catherine MacDougall – Asset Performance Team Leader (Colne, Brent and Crane)
dated 28th April 2021
(ref: HNL 12715 HH) – to John Poole.
