Managing flood risk Sustainable Drainage Systems Graham Brown, Flood and Water Manager Thursday 20th August 2015 Swaffham Town Council

Background on NCC role What are SuDS? SuDS implementation NCC approach Agenda

Norfolk ranked 10th out of 152 authorities with regards to most at risk in relation to surface water flooding. In Norfolk: –37,991 Properties are at risk of surface water flooding –15,965 Properties are at risk of flooding (Flood Zone 2) –46,121 Properties are at risk of flooding (Flood Zone 3) Flood Risk in Norfolk

PFRA Map

Flood and Water Management Act 2010 County Council is now a ‘Lead Local Flood Authority’ with new statutory duties to manage local flood risk in Norfolk A number of organisations classed as ‘Risk Management Authorities’ Changes to funding – more focused on partnership working to deliver schemes Key changes

Risk Management Authorities Surface Run-off Groundwater Ordinary Watercourses Sewer Surcharging Reservoir FailureTidal FloodingMain River Flooding Highway Flooding Lead Local Flood Authorities (LLFA’s) LLFA’s, District Councils, IDB’s Water Companies Highways Authorities Environment Agency

Sustainable Drainage Systems

Mimic natural drainage from a site Reduce Flood Risk Manage runoff close to source Reduction of pollution to receiving water bodies Improvement of amenities & biodiversity Recharge groundwater

Sustainable Drainage Systems SuDS Principles The management train – SuDS components in series Source control – runoff managed as close as possible to where it falls as rain Sub-catchments – division into small areas with different drainage characteristics and land use

Source control Green roof Source control Permeable surface Source control Permeable surface Site control Detention basins Site control Detention basins Site control Detention basins Regional control Retention pond Source control/convey ance Swale Source control/ conveyance Swales Prevention/ Source control Water butts Source control/ conveyance Underdrained swale Source control/ conveyance Underdrained swale Source control/ conveyance Underdrained swales What are SuDS?

Government resolved in late 2014 to deliver SuDS on new developments using the existing planning process. Sustainable Drainage Systems

Planning policy has been strengthened to ensure that SuDS will be provided in new major developments where appropriate from the 6 April Lead Local Flood Authority made a statutory consultee to planning for "major development with surface water drainage" Flood Risk and Coastal Change Section of the Planning Policy Guidance was updated and non-statutory technical standards for SuDS were publishedPlanning Policy Guidance non-statutory technical standards for SuDS Recent changes to Planning

National Planning Policy Framework ("NPPF") published in March 2012.National Planning Policy Framework Written Ministerial Statement on SuDS issued on 18 Dec 2014 and should be viewed as forming part of national planning policy.Written Ministerial Statement National Policy on Flood Risk and SuDS

Para 103, NPPF highlights that when determining planning applications, LPAs should for all types of development; Ensure flood risk is not increased elsewhere Only consider development appropriate in areas at risk of flooding where it can be demonstrated that within the site; –the most vulnerable development is located in areas of lowest flood risk –development is appropriately flood resilient and resistant, including safe access and escape routes where required. –that any residual risk can be safely managed –that priority is given to the use of SuDS National Policy on Flood Risk and SuDS

Government updated its Planning Practice Guidance ("PPG") as part of its SuDS and LLFA planning changes. The PPG emphasises:Planning Practice Guidance –LPAs assess the flood risk posed to new development –LPAs avoid the flood risk posed to new development –LPAs and developers manage and mitigate the flood risk posed to new development Planning Practice Guidance

LPA makes the final decision about the suitability of the SuDS provision and need to: consult the LLFA on the management of surface water, (where appropriate). satisfy themselves that the proposed minimum standards of operation are appropriate. ensure through the use of planning conditions or planning obligations that there are clear arrangements in place for on-going maintenance (of SuDS) over the lifetime of the development. satisfy themselves that the SuDS are designed to ensure that the maintenance and operation requirements are economically proportionate. Determining SuDS on new Developments

SuDS hierarchy & Design - In order of precedence SuDS systems must consider discharge; Into the ground (infiltration) To a surface water body To a surface water sewer, highway drain, or another drainage system To a combined sewer SuDS National Standards

SuDS must be designed to ensure that flooding from the drainage system does not occur; –on any part of the development for a 1/30 rainfall event; –in any part of a building (including a basement); or utility plant susceptible to water (e.g. pumping station or electricity sub-station). Flows that exceed these criteria must be managed to minimise risks to people and property. SuDS National Standards

LLFA role as statutory consultee to planning is created by the Town and Country Planning (Development Management Procedure) (England) Order 2015.Town and Country Planning (Development Management Procedure) (England) Order 2015 LLFA should be consulted on "major development with surface water drainage" LLFA required to respond within 21 days LLFA Role as Statutory Consultee

Government sought to avoid unnecessary over- consultation of the LLFA and to focus their statutory consultation role on major development. In particular: –LPAs to agree with the LLFA the circumstances and locations where LLFA advice should be sought –Expectation that LLFA provide standing advice outside of major developments Involving the LLFA when Determining Applications

EA are no longer a statutory consultee on surface water. EA are still to be consulted on developments; –Within flood zones 2 and 3 –Within areas of critical drainage problems –In the bed of, or within 20 metres of the top bank of, a main river EA statutory consultee changes

NCC's initial approach will be to provide standing advice to all developments up to 250 properties or 5 ha in size. Bespoke advice above this threshold Chargeable pre-application advice in the future NCC Interim Approach

Principle areas to consult the LLFA on are; –All developments with over 250 properties or more and/or 5 ha in size. –Major development sites that are in the floodplain of the Updated Flood Map for Surface Water (1 in 30 year return and 1 in 100 year return extent maps). –Sites adjacent to, or within, known flooding locations (as evidenced by LLFA or other representations). When should NCC be consulted

NCC has received over 190 consultations since April. Resourcing is being reviewed to ensure NCC can meet statutory obligations Updating of guidance to reflect new technical standards Demand

Any Questions?