Consultee Comment-2016874.pdf

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Planning Response Form
DCC REFERENCE:
Brookhill Hall, Brookhill, Pinxton
DCC CONTACT:
Lauren Christopher
PLANNING REFERENCE:
15/00106/SCREEN
LPA CONTACT NAME:
Tim Ball
ADDRESS OF SITE:
Brookhill Hall, Brookhill, Pinxton
DATE RECEIVED:
05/03/2015
DATE DUE:
26/03/2015
SURFACE WATER:
A review of Derbyshire County Council (DCC) surface water model outputs indicate that the proposed
site is unlikely to be subject to surface water flooding during the critical storm duration, 1 in 100 year
return period event. The model shows there may be some surface water pooling close to the
boundaries shared with the watercourses however, this is thought to be associated with fluvial
flooding from the Maghole Brook and its tributaries.
When considering designing drainage systems for exceedence, the developer should consider rainfall
events in excess of the 1 in 100 year return period to allow for extreme events. An analysis of the DCC
surface water model outputs for the 1 in 1000 year critical storm duration rainfall event indicates a
similar yet extended pattern to that of the 1 in 100 year return period. The model also identifies a
large area where surface water may pool located in the north of field 3 from the motorway bridge to
the footbridge over Maghole Brook.
DCC strongly promote Sustainable Drainage Systems (SuDS) to be incorporated within the design of a
drainage strategy for any proposed development, applying the SuDS management train. The applicant
is advised to contact the DCC Flood Team should any guidance on the drainage strategy for the
proposed development be required. DCC encourages that site surface water drainage is designed in
line with the current draft National SuDS Standards, including restricting developed discharge of
surface water to greenfield runoff rates making suitable allowances for climate change and urban
creep, managing surface water as close to the surface as possible and prioritising infiltration as a
means of surface water disposal where possible. Regardless of the site’s status as greenfield or
brownfield land, DCC encourages that surface water discharge from the developed site should be as
close to the greenfield runoff rate as is reasonably practicable. Prior to designing the site surface water
drainage, a full ground investigation should be implemented to fully explore the option of ground
infiltration to manage the surface water in preference to discharging to a surface water body or public
sewer system.
It should be noted that DCC Flood Risk Management Team are not currently responsible for stipulating
a surface water discharge rate for developments further to the advice given above. This should be
agreed with the relevant Local Planning Authority (LPA).
HISTORICAL DATA:
According to DCC held datasets, there are no records of historical flooding within the site boundaries.
However there are reported incidents of flooding approximately 400m to the south of the proposed
site at the recreation ground off Wharf Road, Pinxton. DCC and Bolsover District Council installed a
flood alleviation scheme here however, given the historical records of flooding nearby the applicant
should ensure that there is no increase in flood risk downstream of the site due to the development.
FLUVIAL DATA (ORDINARY WATERCOURSE AND MAIN RIVER WHERE APPLICABLE):
Parts of the proposed site appear to interact with Flood Zone 3.
The Maghole Brook flows between the three fields from north to south, flowing along the northern
boundary of field one, the southern boundary of field two and the north eastern boundary of field 3.
An unnamed tributary flows from west to east between fields one and three (along the south eastern
boundary on field one and the north western boundary of field three) and joins the Maghole Brook
opposite field two. Another unnamed tributary flows close to the western boundary of field two and
joins the Maghole Brook in between fields one and two. DCC do not generally undertake or hold any
data relating to modelling on specific ordinary watercourses. The applicant is advised to contact the
Environment Agency (EA) who hold modelling data for Main Rivers and some ordinary watercourses.
Due to the historic mining and mineral extraction operations in Derbyshire, networks of old stone
soughs (drainage channels, sometimes known as adits) may exist beneath the ground surface in parts
of the County (particularly North East Derbyshire District, High Peak Borough, Derbyshire Dales District
and the Peak District National Park area). The applicant is therefore advised to investigate the
potential for hidden watercourses existing on the land prior to any works being undertaken.
WATER FRAMEWORK DIRECTIVE/WATER ENVIRONMENT DATA:
The Maghole Brook and unnamed watercourses are not currently assessed under the WFD (Water
Framework Directive, 2000). No activities or works should deteriorate the status of these
watercourses as the main objective of the WFD is to prevent deterioration in ‘status’ for all
waterbodies. All waterbodies should reach ‘good ecological status’ by 2015 according to the directive.
The ecological condition of any receiving watercourse can be protected by the implementation of a
SuDS scheme with an appropriate number of treatment stages that are appropriately maintained.
A brief review of the county ecological information shows that there have been no reported ecological
records within close proximity of the site.
GROUNDWATER DATA:
An analysis of the British Geological Survey (BGS) data is summarised below:
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The groundwater may be vulnerable to contamination therefore infiltrating water should be
free of contaminants,
Groundwater is likely to be less than 3m below the ground surface for at least part of the year,
The subsurface is potentially suitable for infiltration SuDS, and
Increased infiltration is unlikely to result in ground instability.
It is recommended that a site specific ground investigation is undertaken for the site based on the
review of the BGS data.
OTHER RELEVANT INFORMATION AND COMMENTS:
DCC do not hold any DG5 records for sewer flooding. Please contact your local water company for this
information.
Following the 2007 Pitt Review recommendation, Schedule 3 of the Flood and Water Management Act
(2010) designated DCC as the SuDS Approval Body (SAB). Following the enactment of this legislation,
DCC would have been responsible for approving all construction with drainage implications and
adopting any approved SuDS. However, Defra released a consultation on 12th September 2014 which
outlined an alternative way of delivering SuDS through amendments to existing planning guidance.
Following the outcome of this consultation, the SAB will no longer be implemented and LPAs will have
the duty to approve SuDS systems for new developments, with assistance from a range of consultees.
A consultation was released by DCLG on 18th December 2014 which proposed making LLFAs a
statutory consultee to the updated planning system. The updated planning system will come into
force in April 2015 however it is as yet unclear what the precise role of DCC as a consultee to this
process will be. DCC do not adopt any private SuDS schemes. As such, it should be confirmed prior to
commencement of works which organisation will be responsible for SuDS maintenance once the
development is completed.
As of the 6th April 2012 the FWMA transposed consenting powers under the Land Drainage Act (LDA,
1991) to DCC. Therefore any works in or nearby to an ordinary watercourse require consent from DCC.
(e.g. an outfall that encroaches into the profile of the watercourse, etc) would require consent under
the LDA from DCC. Upon receipt of any application (including the legislative fee) DCC has an 8 week
legislative period in which to make a decision and either consent or object the proposals. If the
applicant wishes to make an application for any works please contact Flood.Team@derbyshire.gov.uk.
DCC holds a suite of information that can inform site development across Derbyshire. The
information within this document has been interpreted and provided by an officer from the flood
risk management team.
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Historical data has been collated from a range of sources and is anecdotal. The provision of
this data is suggested to act as a guide only.
Fluvial data has been provided by the EA however the applicant is advised to contact the EA
for further information should the site lie within the floodplain of a Main River.
DCC hold BGS data under a licenced agreement and therefore are not licenced to reproduce
this information into the public domain.
DCC have modelled surface water flooding for the whole of Derbyshire. The model output
gives an indication of the broad areas likely to be at risk of surface water flooding and is
intended to act as a guide only and cannot be used to identify specific properties at risk.
Further information regarding the WFD, ecology and biodiversity should be obtained from
the EA and Natural England.
COMPLETED BY:
CHECKED BY:
DATE SUBMITTED TO LPA:
Lauren Christopher
DATE:
DATE:
10/03/2015
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