Appendix B: Filter strip checklist /
Table B.9 Design assessment checklist: filter strip
Generalinformation
SiteID
Asset ID(s)
Filter strip location(s) and co-ordinates / Drawingreference(s)
Dateofassessment / Specificationreference(s)
Primary function(s) of filter strip / Conveyance/treatment
Check / MDR / Summarydetails1 / Acceptable(Y/N) / Comments/remedialactions
Dimensions(Section15.2)
Length of contributingdrainage area (indirection of flow), L (m) /
Lengthoffilterstrip(indirectionofflow),f(m) /
Width(m)
Longitudinalslope(1in ?) /
Inflows(Section15.8.1)
Provide a description of thecontributing
catchment landuseandits size(m2)
Doesthedesign include:
▪asuitable flow spreading device?
▪appropriatedropsfromtheadjacentsurface into the filter strip? /
Outfallarrangements(Section15.8.2)
Provide details of dischargearrangementsfrom filter strip
Isthe filter stripdesigned to allowinfiltration? If yes, attachtheinfiltrationassessment
Is a geomembranerequired to preventinfiltration? If yes, give reason andreferencespecificationordrawing
Depthtomaximum likelygroundwater level (m)
Conveyance(Section15.4)
Proposedvegetation, and assumed roughnesscriteria (Manning’s “n”)
Maximumvelocityacross filter strip at fullflow conditions(m/s) /
Maximum water depth at full flow conditions(m) /
Waterqualitytreatment(Section15.5)
For the 1 year 30 minute eventconfirm: /
Flow height is acceptableforeffective
treatment
Or
Maximumvelocity is acceptablefor /
effectivetreatment
Criticalmaterialsandproductspecifications(Section 15.9)
Geomembrane
Geotextile(non-woven)
Topsoil
Other(includingproprietarysystems):
Landscape/biodiversity(Sections15.6,15.7and 15.10)
Doestheproposedplantinghave potential to create biodiverse habitats?
Have native plant speciesbeen used?(Note ifornamentalspecies areproposed, give reasons and describemeasures that prevent theirmigration tonaturalwaterbodies.)
Istheproposedplantingappropriatetothelocation, visually, relative to gradient,waterdepths etcandwithrespect toaccessand maintenance?
Where relevant, confirmplantingdesigndoes not adverselyimpact highwayvisibility and safetyrequirements (checkwithhighway authority)
Istheproposedtopsoilprofilesuitable tosustaintheproposedplant speciesandisit sufficientlypermeable?
Constructability(Section15.11)
Arethereanyidentifiableconstructionrisks?Ifyes,stateandconfirmacceptableriskmanagementmeasuresareproposed
Maintainability(Section15.12)
Confirm that accessformaintenanceis
acceptableand summarisedetails
Aretherespecific features that are likelyto posemaintenancedifficulties? If yes,identifymitigationmeasuresrequired
Filterstripdesignacceptability / Summarydetailsincludinganychangesrequired / Acceptable(Y/N) / Datechangesmade
Acceptable:
Minorchanges required:
Majorchangesrequired/redesign:
Note
1Ifthereis an MDR(asindicated)confirmwhetherornotthisismetandprovidedetails of any variations.
1