To: Jonathan Edwards, Wychavon District Council
Date: 04.09.2014
From: Martyn Wilson, Principal Planner
Subject: Lead Local Flood Authority consultation response in respect of land
at Defford Airfield, Defford, Worcestershire.
Recommendation: That these comments are taken into account in the
determination of this application
Summary of Worcestershire County Council response: In respect of the
departments contributing to this advice (namely Strategic Planning and
Environmental Policy and the Flood Risk Management Team) Worcestershire
County Council.
Whilst LLFA officers do not object to the proposal at this stage, we do have
concerns as set out in our detailed response below with regard to the
absence of appropriate assessment and consideration of the ordinary
watercourse and the risk of flooding in this location.
The comments below are intended to help improve the sustainability of the
proposal and to direct the applicants towards best practice.
Any departments not included within this response may choose to comment
and/or object separately.
Application No: W/14/01244/PN
Location: W/14/01244/PN – Land at Defford Airfield, Defford.
Proposal: The development of a 49.86 MW solar farm on land at Defford
Airfield, Defford, Worcestershire. The proposal is for a ground mounted solar
farm with arrays of solar PV modules set out in rows and mounted on a
framework system which is driven into the ground.
Applicant: Solar Planning Limited
Introduction
Martyn Wilson
Principal Planner
Business,
Environment and
Community
Directorate
County Hall
Spetchley Road
Worcester
WR5 2NP
The Flood and Water Management Act (2010)
The Flood and Water Management Act (FWMA) delegated upper-tier and
unitary authorities as Lead Local Flood Authorities (LLFA) with responsibility
Tel 01905 768367Fax 01905 766498Minicom (01905) 766399DX 29941 Worcester 2
mwilson2@worcestershire.gov.ukwww.worcestershire.gov.uk
Document2
for their respective area's Local Flood Risk Management Strategy.
Worcestershire County Council is therefore the LLFA for Worcestershire.
This role currently relates to ordinary watercourses, surface water and
groundwater flooding (fluvial flooding from main tributaries is still currently the
responsibility of the Environment Agency).
The FWMA has also delegated LLFAs a number of other statutory powers
and duties, extending previous responsibilities for flood risk management,
these will be of importance in considering proposals for flood risk
management for the proposed development and include:
•
•
•
•
Powers to request information from any person in connection with
the authority's flood and coastal erosion risk management
functions;
Power to designate structures and features that could affect
flooding and are considered to be significant when assessing local
flood risk;
A duty to establish a Sustainable Drainage Systems (SuDS)
Approving Body (SAB) with responsibility for approval of all
drainage plans and the adoption and maintenance of SuDS that
serve more than one property in new developments (we are
currently awaiting confirmation of commencement from Defra);
Following commencement of paragraphs 32-34 of Schedule 2 of
the FWMA on the 6th of April 2012 transfer has been made of the
regulatory powers (consenting and enforcement) on Ordinary
Watercourses from the Environment Agency to LLFA's (internal
drainage boards will still have this role on ordinary watercourses in
their system).
As permitted by FWMA a number of statutory functions of the LLFA have
been delegated to the District Drainage authorities. For Malvern Hills District
Council, Worcester City Council and Wychavon District Council this is the
South Worcestershire Land Drainage Partnership (SWDLP), this currently
includes the ordinary watercourse consenting function.
The 'emerging' Worcestershire Surface Water Management Plan
The County Council is also working in partnership with partners including
District Authorities, Severn Trent Water and the Environment Agency to
reduce the risk of surface water flooding in Worcestershire. This work
includes the development of a Worcestershire Surface Water Management
Plan (SWMP).
The emerging SWMP focuses on a high-level overview of flooding in
Worcestershire using existing data to identify a list of historical and potential
future flooding locations (including areas that may have not flooded in the
past) with potential for ‘quick win’ solutions and identify locations where
further investigation and consideration would be beneficial. This evidence
base has been utilised by JBA Consultants to inform revisions to the South
Worcestershire Level 2 Strategic Flood Risk Assessment. This evidence
base has also been used to inform the LLFA's consultation response to the
development proposals.
These comments represent those of Worcestershire County Council as the
Lead Local Flood Authority (as determined by the Flood and Water
Management Act 2010) and are officer comments only.
Summary
This is a significant development affecting ordinary watercourses and with
parts identified as falling within flood zone 3. It is therefore disappointing to
note that the LLFA has received no pre-application consultation from the
applicants. This is contrary to the advice of the Environment Agency (West
Area: Midlands Region) Development Guidance which advises applicants
"to contact the Lead Local Flood Authority Land Drainage Team (LLFA) in
your area to discuss proposals in or adjacent to ordinary watercourses and
local flooding issues related to them".
In addition we are concerned that appropriate assessment and consideration
has not been taken of the ordinary watercourses and the risk of flooding in
this location as set out in our detailed comments below.
Detailed comments
1. The LLFA supports a partnership approach to discussion regarding
development proposals of such a strategic nature and seeks a holistic
and multifunctional approach to surface water management.
2. However, whilst other parties within the County Council may have
been involved in pre-application discussion (such as the Highways
Authority) officers of the LLFA have not to date been contacted for
pre-application discussions with regard to flood risk management
proposals for the proposed development.
Flood Risk Management
3. The proposed solar panels in the south west corner of the site are
shown on the Environment Agency flood map to be located in Flood
Zone 3 (high probability).
4. The flood plain is considered to be primarily associated with Bourne
Brook; an ordinary watercourse that flows in a south/south eastern
direction through the site. A section of the brook running through the
south west of the site is in culvert. There is also a minor tributary to
the Bourne Brook running in a west/south-westerly direction through
the southern part of the site. This section of watercourse is also in
culvert through part of the site and it is considered that this may
contribute to the identified flood risk.
5. The updated version of the national scale surface water maps
(uFMfSW) published by the EA in December 2013 and the 'emerging'
Worcestershire SWMP indicate a ‘low’ to ‘High’ flood risk on the A44
and parts of the wider Defford site.
6. Paragraph 2.9 states that "there are no historical records of flood
incidents on this site, either from the EA or within the SFRA." This is a
greenfield/brownfield site and the absence of records of flooding
should not be taken as an assumption that the site does not flood.
7. The Flood Risk Assessment (FRA) submitted with the application
suggests at paragraph 3.2 that the development is entirely within
Flood Zone 1 and so is at low risk of flooding. However, it should be
noted that some watercourses have not been modelled on EA Flood
Zone Maps, which primarily show flooding from main rivers, not
ordinary watercourses with a catchment of less than 3km 2. It is
therefore considered premature to conclude that the proposed site is
entirely within flood zone 1 and not subject to flooding.
8. In addition the Environment Agencies generalised modelling used to
produce the flood maps may have only picked up the lower ground
levels adjacent to where the watercourse is culverted and does not
necessarily confirm that the other areas proposed for the panels and
shown to be within Flood Zone 1 are out of the floodplain.
9. Indeed, it would appear that a number of solar panels and supporting
infrastructure are located in flood zone 3 and 3a.
10. Further evidence is therefore required to ensure that the proposed
panels are located out of the floodplain so as to avoid the
development causing a reduction in flood storage capacity and to
protect the proposed installation.
11. A more detailed topographical survey should be undertaken for the
area of the site considered to be at flood risk. An analysis should also
be undertaken to assess the capacity of the culvert to convey flood
flows during a range of return periods (i.e. 1 in 20, 1 in 100, 1 in 100
plus climate change) in order to verify the flood map extent and to
identify a flow route should the culvert block.
12. References should be made within the FRA to the South
Worcestershire SFRA (December 2012), which also contains FMfSW
30 year & 200 year flood risk maps, supplemented by EA uFMfSW
published in December 2013, NPPF, NPPF Technical Guidance,
former PPS25 Practice Guide, SuDS Manual and any other relevant
Standards and Codes of Practice.
Ordinary Watercourses
13. The Worcestershire Green Infrastructure Partnership, the Environment
Agency and SuDS guidance/best practice advocates the 'opening up'
of culverted watercourses where possible as this provides
multifunctional benefits including water quality improvement, flood risk
management and biodiversity benefits.
14. Paragraph 2.2 notes that "there are smaller streams and ditches that
discharge into the Brook within the site". These and any other ditch
watercourses along field boundaries and pond features on the site
should also be considered and accommodated within the Drainage
Strategy.
15. For clarity an ordinary watercourse is defined under the FWMA as a
“watercourse” that does not form part of a “main river” and includes
streams and all ditches, drains, cuts, culverts, dikes, sluices, sewers
(other than public sewers within the meaning of the Water Industry Act
1991) and passages, through which water flows as defined by the
Land Drainage Act 1991 [section 72(1)].
16. The applicants are reminded that the LLFA is the consenting body for
structures or works that may affect flows along an ordinary
watercourse. Consent under the Land Drainage Act 1991 for such
features will required from the SWDLP under powers delegated to it by
Worcestershire County Council (as LLFA) and will ultimately make
recommendations for the proposed diversion.
Water Quality
17. We would advise that measures are taken to minimise and reduce silt
runoff /sediment problems.
18. Diffuse and point source pollution from agricultural and urban sources
is a significant issue for parts of the River Avon and its catchment. We
would therefore expect as a minimum two stages of water treatment.
SuDS and Green Infrastructure
19. The applicant has indicated that they do not intend to provide any
formal drainage.
20. The applicants are reminded that FRAs and drainage strategies
should assess the risks of river (fluvial), surface water and all other
sources of flooding. Once the risks have been assessed mitigation
measures should be identified to reduce or manage the risk on and off
site to an acceptable level.
21. Sustainable Drainage Systems (SuDS) should be included in
developments to manage surface water run-off and to prevent it from
exacerbating flood risk. SuDS should also help to protect and improve
water quality and add aesthetic and amenity value such as biodiversity
and ecological connectivity to development.
22. SUDs offer significant advantages over conventional piped drainage
systems in reducing flood risk by reducing the quantity of surface
water run-off from a site and the speed at which it reaches water
courses, promoting groundwater recharge, and improving water
quality and amenity.
23. Approved Document Part H of the Building Regulations 2010
establishes a hierarchy for surface water disposal, which encourages
a SUDS approach beginning with infiltration where possible e.g.
soakaways or infiltration trenches.
24. The LLFAs preference is for the inclusion of surface levels SuDS
features which promote the opportunity for ecological connectivity,
biodiversity enhancement, water quality improvement and which
contribute to the design aesthetic of the built environment.
25. We are therefore particularly disappointed to note the absence of any
surface level treatment stages within the accompanying drainage
strategy and the absence of an opportunity to capture the
environmental and aesthetic benefits this may bring.
26. We would therefore welcome clarification of the reason and
justification as to why the proposed approach has been adopted. The
proposed drainage strategy should demonstrate how sustainable
drainage system techniques (SUDs) will be used with any obstacles to
their use clearly justified.
27. Existing ditch watercourses in the area should be included where
possible in the drainage strategy proposals as part of a
comprehensive SuDS approach.
28. A minimum 8.0m easement should be provided to and around all
watercourses, SuDS features and other blue infrastructure for
maintenance access.
SuDS and the SuDS Approval Body
29. The current situation regarding long term maintenance of SuDS is that
even if the relevant sections of the FWMA 2010 are enacted, National
Standards are published and the SAB created by Worcestershire
County Council (LLFA), this will only apply to new applications post
enactment. The LLFA is currently awaiting confirmation of enactment
of schedule 3 it is therefore unlikely that adoption of SuDS on this site
will occur even if it is considered compliant by the LLFA/SAB.
30. To be clear until enactment of Schedule 3 of the FWMA the
LLFA/County Council is not legally obliged to adopt SuDS and current
view is not to retrospectively adopt such schemes. The Applicants will
therefore need to put in place appropriate and robust arrangements for
the future maintenance of SuDS and for the lifetime of the
development.