BabtleBrown & Root RiverLittle Ouse (Brandonto ThetfordNavigation) Pre-FeasibilityStudy Stage2 Report t:t-) '. :'j ,,...i _t-ji;:1 1,:il !" *# E{-:s- ',.jij EnvironmentAgency Anglian Region BBR Ref: 0006077/D4l135 EA ProjectRef: LVN 17010 Babtie Brown & Root JV 8 The SquareMartlesham Heath lpswich Suffolk lP5 3SL Tel 01473624326 Fax 01473623021 BabtieBrown & Root River Little Ouse Brandon to Thetford Prefeasibility Study - Stage 2 Report Rev Date Purpose Draft 26t6t03 Draftfor Discussion 20t8t03 Stage1 Reportissue A 1611tO4 Stage2 Report(Draft for Discussion) B 16t2t04 Stage2 Reportdraft in preparation C 25t5t04 Stage2 Reportincorporating EA commentsof 2614104 D 17t10t05 Stage2 Report(Final) incorporatinq EA comments Front Cover Photo Abbey Heath Weir, River Little Ouse, Thetford. 35 Stage 2 Flnal Revo.dc RIVERLITTLE OUSE (BRANDONto THETFORDNAVIGATION) Notes Pagesnot printed (or reprinted) 2: Blank 28: Blank 29: Titlepage only - AppendixA, EnvironmentalReport. 52: Blank 53: Titlepage only - Citations(Appendix 3 - sic) 54: Blank 55 - 67: ThetfordGolf Course And Marsh,Sites of SpecialScientific lnterest, Conservationof Wild Birds. SeePages 35 to 47 in originalreport. 68: Blank 69: Titlepage only - AppendixB, Photographs 70 - 76 14photographs. See pages 50 to 56 of originalreport. 77: Titlepage only - AppendixC, Works Required for Navigation 78 - 79 Scheduleof newworks - Seepages 58 & 59 of originalreport 80: Blank 81: Titlepage only - AppendixD, CostsEstimates 85: Titlepage only - AppendixE, EconomicAssessment 91: Titlepage only - WorkingGroup Consultation 92: Blank 93 - 94: WorkingGroup. See pages 67 & 68 of originalreport 98: Blank 99: Titlepage only - AbstractionLicence Summaries 100:Blank 103-106:River Flow Records 107',Drawings BabtieBrcwn&Root River Little Ouse Brandon to Thetford Prefeasibility Study - Stage 2 Report Tableof Gontents |NTRODUCT|ON............. '....".""....'....4 TECHNTCALASSESSMENT............... .'........."""".8 swoT ANALYSIS.. .'.....13 PLANN|NG|SSUES....... .......'.."'..'...16 ENVTRONMENTAL1SSUES.........,....... ..".......'."'18 scHEMECOSTS....... .'..............'......20 ourLrNE BENEFTTS.. ...............'......21 ECONOMTCBENEFITS.. ............----.-22 coNcLusroNs.............. ..........-.......2s RECOMMENDATIONS... ...-...----".....27 Appendices AppendixA - Environmentallmpact Assessment Report AppendixB - PhotograPhs AppendixC - WorksRequired for Navigation AppendixD - CostEstimates AppendixE - EconomicAssessment AppendixF - WorkingGroup Consultation AppendixG - AbstractionLicence Summaries AppendixH - RiverFlow Records Drawings 0006077/01/01 - StudYArea 0A06077101102 - SSSI's 0006077/01/03 - SAC's 0006077101104 - CurrentStructures and PreferredLock Locations, Forestry Commission 0006077/01/05 RiverCorridor Habitat, Forestry COmmission 0006077/01/06 - PotentialEnhancement Areas, Forestry Commission 0006077101107 - ScheduledAncient Monuments 00060771D2108 - HistoricStaunches and ExistingWeirs 00060771D2109 - NavigationProposals - Plan& Longsection Rr\2003v'fir60r7 EA Brandon to 35 Stagc 2 Flml RevD.dc 1 ol 107 BabtieBrcwn&Root River Little Ouse Brandon to Thetford Prefeasibility Study - Stage 2 Report SUMMARY 1.1 This report presentsthe initial environmentaland technicalassessments for providing enhancementsto the environment,and navigationon the Little Ouse betweenBrandon and Thetford. 't.2 The areas of potentialenvironmental enhancement have been identifiedbased on informationprovided from a corelist of consultees,particularly the ForestryCommission. The key englneeringworks required for the navigationto be reopenedbetween Brandon and Thetfordhave been identified. 1.4 Budgetcosts and benefitsfor theseproposals have been determined; the costsare in the regionof f6.5 to €7.5million. 1.5 An assessmentof the economicbenefits has beencarried out for a rangeof scenarios. The medium(intermediate) case scenarios suggest that the navigationproposals would yiefda positiveNPV after approximate$ 2A b 25 years. Thereis scopeto restorethe floodplain in the vicinityof Two MileBottom and to a lesser extentSanton Downham. However, the affectof increasedlevels on the flooddefence aspectshas not beenfully examined at this stage. Investigationswould be neededto determinethe potentialaffects of navigationon river flowsdue to increasedwater levels, and confirmthe technicalfeasibility of the proposals. 1.8 Furtherenvironmental studies are requiredto identifythe presenceof protectedspecies alongthe rivercorridor and considerthe effectsof extendingthe navigationto Thetford.In addition,consideration should be givento the effectsof navigationon riverbank stability fromwave action.These issues would need to be addressedunder the environmental mitigationproposals for the scheme. R;U0030006077EA Brandon to Thetfqd\Adm\D@uments\IN-'35 Stage 2 Final RevD.d@ 3 of 107 BabtieBrown & Root River Little Ouse Brandon to Thetford Prefeasibility Study - Stage 2 Report INTRODUCTION Background 2.1.1 The river LittleOuse is a gentlysloping river draining the low-lyingland of the Brecksin Norfolk,and meandersfrom Thetford,past SantonDownham, Brandon and Hockwold- Cum-Wiltonuntil it flowsinto the riverGreat Ouse at BrandonCreek. 2.1.2 The river befueen Brandonand Thetfordflows throughthe ThetfordForest, part of which is part of the BrecklandForest SSSI and part of in the Thetfordgolf courseand Marsh SSSI. 2.1.3 The river LittleOuse is at presentnavigable by small boats up from its confluencewith the riverGreat Ouse up to Brandonon the NorfolUSuffolkborder. Limitations on the size of boatsthat can navigateto Brandonare as follows: r Limited headroom of approximately2]m at the railway bridge downstreamof Brandonlock. Thereis limitedwidth, length, depth and headroomat BrandonLock (4m wide,14m long,1.2m deep and 2m headroom). 2.1.4 Boatscurrently have access from the riverLittle Ouse to the riverGreat Ouse, where they can navigatenorth to the DenverSluice complex or south towardsEly. Accessto this watenruaysystem will enable boats using the river Little Ouse to gain access to the proposedFens Waterway Link and Nar OuseNavigation (to King'sLynn). 2.'t.5 The section of the river Little Ouse upstreamof Brandon is not navigabledue to insufficientwater depth in placesand restrictionscaused by existingstructures such as bridgesand gauging weirs. 2.1.6 There is considerableexisting amenity value along the lengthof river betweenBrandon and Thetford,and there are severalenvironmental designations covering this area (see Appendix A). Use is made of the watercoursefor canoeing and there are other recreationaluses of the area. 2.1.7 The ForestryCommission have extensiveresponsibilities for the managementof land adjacentto the river, and are keen to improvethe water level managementso as to improvesome of the existingland uses. Project Aims 2.2.1 The purposeof this schemeis to enhancethe amenitiesprovided from the river Little Ouse and the adjacent area of the Thetford Forest Nature Reserve. The Forestry Commissionis continuallyworking tro enhance the localarea through the reinstatementof natural habitats associatedwith the flood plain. The boating communityis keen to increasethe currentnavigation on the riverLittle Ouse to Thetford. R:\20{r3\0mo0z EA Brandon to Thetio.d\Adm\Itcumts\D4-135 Stage 2 Flml Revt .da 4 ot 1O7 BabtieBrcwn & Root River Little Ouse Brandonto ThetfordPrefeasibility Study - Stage2 Report 2.2'2 The project group's aims are to enhance and improve the provisionof navigable waterwaywhilst maintaining/improving the standardof floodprotection curently offeredto the respectivearea. The key membersof the projectgroup are: r EnvironmentAgency . KeystoneCommunity Partnership . ForestryCommission r EastAnglian Waterways Association . GreatOuse Boating Association . lnlandWaterways Association o BrecksCountryside project o EnglishNature o ForestHeath District Council e BrecklandDistrict Council 2.2'3 The purpose of this prefeasibilitystudy is to examine the issues associatedwith reopeningthe lengthof watercoursebetween Brandon and Thetfordto navigation,and to identifyany potential enhancements to theamenities in thearea. 2'2.4 This study has been prepared by Babtie Brown & Root commissionedunder the EnvironmentAgency's NEECA frameworkagreement. This report identifiesthe key environmentalissues and the scope of work, which would be requiredto reopen the navigation. Tasks 2.3.1 The purposeof this prefeasibilitystudy is to identify: r The currentwater level management regime and standardsof floodprotection offeredto the studyarea. The waterlevel management requirements necessary to enablethe re-openingof the riverLittle Ouse to navigation,between Brandon and Thetford,and the restrictions imposedon its users(i.e minimumdraft, widths and headroometc). Any potentialfor floodplain restoration within the areaof the NatureReserve. The scope/extentof futureworks required to implementthe scherne. r Outlineoptions and associatedcosts. o Outlinebenefits. Associatedinterests; nature conservation, landscape, fisheries, recreation, amenities,local communities, land use,archaeology, planning issues, water resourcesand water quality. Study Area 2.4.1 The extentof the studyarea is shownin drawing00060Z7101101. 2'4.2 A descriptionof the locationis givenin Section2.2 of the EnvironmentReport under AppendixA" Photographsof the site are shownunder Appendix B. R:U003\00060n EA Brildon to Thetford\Adm\Dcumsts\D4-l35 Stage2 Final RevD.d@ 5 of 107 BabtieBrcwn & Root River Little Ouse Brandon to Thetford Prefeasibility Study - Stage 2 Report NavigationHistory 2.5.'l