All of the Above Shouldbeagreed(Where Relevant) Withthe LPA, Internaldrainageboard,Environmental

C753 The SuDS Manual
Appendix B: SuDS planning and design processes /
Table B.1 Suggested pre-application discussion material
Ref / Requirements / Details(orreferencedocumentation) / Accepted?
(a) / Any planning and environmentalobjectivesforthe site that shouldinfluencethesurface water managementstrategy – theseobjectivescanbe put forwardbyboththedeveloper and theapproving body/LPA and shouldbeagreedby all parties
(b) / The likely environmentalortechnicalconstraints to SuDSdesignforthe site – these
shouldbeagreed by allparties
(c) / Therequirements of thelocalSuDS approval and adoptionprocesses.Theseshouldbeprovided to the developer bythedrainageapprovingbody
(d) / ThesuiteofdesigncriteriatobeappliedtotheSuDSscheme(takingaccountof(a) to(c))
(e) / Evidence that theinitial development designproposalshaveconsideredtheintegrationandlinkageofthesurfacewater managementwithstreetlayouts, architecturalandlandscapeproposals
(f) / Anassessmentof strategicopportunitiesforthesurfacewater managementsystemto deliver multiplebenefitsforthe site – thisshouldbeprovidedbythe developer andshouldincludethestrategic useof publicopenspaceforSuDS
(h) / Thestatutory and recommendednon-statutoryconsulteesforthedesignproposals –thisshouldbeprovidedbythe approval bodyorLPA
(i) / Thelikely landand infrastructureownershipfordrainageroutesand pointsof discharge(includingsewerage assets)
(j) / Anassessmentofstatutoryconsulteeresponsibilitiesand requirements,includingtimescalesforany likely requiredapprovals/consents
(k) / Any potential localcommunityimpacts,health and safetyissuesorspecificlocalcommunityconcerns and drainageapprovingbodyrequirements that shouldbeaddressed bythedetaileddesign
(m) / Anassessmentof costimplications ofstakeholderobligations
(n) / Anagreedapproachtothedesignandmaintenanceof thesurfacewater managementfortheproposedsite

Note

All of the above shouldbeagreed(where relevant) withthe LPA, internaldrainageboard,environmental regulator, watercompaniesandsewerageundertakers.TheSuDSplanningprocessshouldbeclosely linked to thedevelopmentplanningprocess,andthedrainagedesignshouldbeintegratedwherepossiblewithinthedesign of thedevelopment as a whole.

Table B.2Conceptual drainage design documentation suggested for submission at outline planning
Ref / Requirements / Details(orreferencedocumentation) / Accepted?
(a) / Definition of the natural drainagecharacteristicswithin, and hydrologically linked to,thesiteanddemonstrationthatthedrainageproposalswillintegratewithandnotcompromisethefunction of the natural drainage systems – natural flow paths forsurface water runoffshouldbeidentifiedon a planwhereappropriate
(b) / Definition of state, performance and ownership of any existing site surface waterdrainageinfrastructure anddemonstration that thedrainageproposalsconsider, use orprotectthesesystems (whereappropriate)
(c) / Proposedstrategicapproach to managing on-sitefloodriskfrom all sources(aspart ofor in alignmentwiththeFloodRiskAssessment/floodconsequences assessment), andimplications of existing floodriskforproposedSuDSdesign
(d) / Outlineassessmentof existinggeology, groundconditions(includingcontaminationand stability) and permeabilitythroughdesk-basedresearch(eg a review of geological/hydrogeological maps, infiltration potential maps and site visit observations) – todeterminethesuitability of infiltrationdrainageforthe site runoff.Infiltrationtestsshouldbecarried out at thisstage wherever possible. If infiltration is proposed but tests arenot available an alternative outfallshouldbeidentified in casefuturetests show thatinfiltration is not possible
(e) / Identification of therequirements of anyenvironmentally sensitive potential receivingwaterbodiesfortherunoff(eggroundwater protectionzones,archaeologicalfeatures,receiving water bodyenvironmental designations)
(f) / Theimpact of any stakeholderengagementonthedesignandproposedcommunityengagementplans
(g) / Confirmation of dischargepoints (ie to ground, watercourseorpublicsewer)for allreturnperiod events
(h) / Confirmation of thedesigncriteriafortheSuDS system (including an assessment of theneed and opportunityfor rainwater harvesting and use),including climate change andurbancreepallowances
(i) / ConceptualSuDSdesignincludingInterception,treatment, conveyance, peak flow andvolume control,storage and exceedanceroutes and components(anddemonstrationthat requiredindicativestorages and conveyance flows canbe delivered onsite)
(j) / Proposedmulti-functional use of SuDSspace to meetcommunity and environmentalrequirements (where possiblegreen infrastructure) and the potential contribution of the surface water management system (eg BREEAM Community, DCLG, 2008, andBirkbeck and Kruczkowski, 2012) to the development designobjectivesforsustainability
(including climate resilience)
(k) / Proposedsplit of theSuDSbetween private and public
(l) / Confirmation of approval and adoptionarrangementsfor all SuDScomponents
(m) / Details of any requiredoff-siteworks and consents
(n) / Appropriateconsideration of themaintainability of theproposedSuDS
(o) / Appropriateconsideration of theconstructability of theproposedSuDS(includingtherequirementsfor phasing orprotection of components)
(p) / An initialhealth and safetyriskassessment

Note

Table B.3 Detailed drainage design documentation suggested for submission at full planning
Ref / Requirements / Details(orreferencedocumentation) / Accepted?
(a) / Whereinfiltration is proposed, an acceptableInfiltrationAssessment has beensubmitted,includinganygeotechnical test results and evaluations
(b) / Aschemedesignassessmentwithappropriatesupportingcalculationsthat hasbeensubmittedthatdemonstratesdesignconformitywiththerequireddesigncriteriaforthesite; justification of anynon-compliance to nationalorlocally set standards
(c) / Plansoftheproposeddrainagesystem,showing:
▪drainagecatchment and sub-catchment areas (includingimpermeable andpermeablezones, and any phasing details)
▪existing and proposed site sections and levels
▪long- and cross-sectionsfortheproposeddrainage system (includingexceedanceflow managementroutes) and final buildingfinishedfloor levels
▪detailsforconnectionstowatercourses andsewers
▪maintenanceaccess and anyarisingsstorage anddisposalarrangements
▪operationalcharacteristicsof anymechanicalfeatures
(d) / Allnecessaryconsentsrequiredforoff-siteworks
(e) / Commitmentsfor approval and adoptionarrangementsfor all elements of the system(includingexceedance flow management components); commitments to anycostcontributions, valuation and security of anyrequirednon-performancebond
(f) / Appropriateconsiderationandmanagement of anyhealthandsafetyissuesrelatingtoSuDSimplementation
(g) / Thedesignofeachelementundertakeninaccordancewithbestpractice (usingdetaileddesignchecklists,where required)
(h) / Specificationsprepared and approved for all materials used in thedesign
(i) / AconstructionmethodstatementfortheproposedSuDSsystemsubmittedincluding:
▪constructionprocesses to protecttheSuDSfunctionality(includingtheprovision ofany requiredtemporarydrainagesystems)
▪programmingtoprotecttheSuDSfunctionality
▪landscapeplanting
▪consideration of accessforinspectionsbytheapprovingoradoptingorganisation
(j) / A Maintenance Plan for the proposed SuDS submitted including:
▪a description of the system andhow each part of the system is expected to work
▪managementobjectivesforthe site
▪inspection and maintenance schedules, material, tools and initialcostestimates
▪maintenance access points, easements and outfalls
(k) / An information and communications plan for the proposed SuDS scheme submitted, where appropriate, including:
▪communication with and education of existing residents
▪communication with and education of new residents
▪site and SuDScomponentspecificinformationboards
▪local communityeducation and educationstrategies (egthrough schools).Note: this is only likely to berequiredonlarger sites and maybeprovidedbythe drainageapprovingbodyorthe developer (tobeagreedbetweenthem)