3 NATIONAL RIVERS AUTHORITY ANGLIAN REGION WATER RESOURCES PLANNING: DEBEN GROUNDWATER UNIT WATER RESOURCES MANAGEMENT PLAN Andy Turner, Assistant Engineer (Water Resources) February 1995 DOCUMENT CONTROL SHEET Project: WATER RESOURCES MANAGEMENT PLANS Title: DEBEN GROUNDWATER UNIT: WATER RESOURCES MANAGEMENT PLAN File Ref: 656/3/6 Document Approval and Amendment Record Version No.: Final Report Status: Internal working document. Author: Andy Turner Drafts Checked By: Pauline Smith Barry Barton David Evans Alan Hull Gerard Stewart Dave Clarke (part) Bob Hillier Approved: *5^ * Date: February 1995 Purpose and Distribution: To refine and apply the principles of both the National and Regional Water Resources Strategies at a local scale, and to provide water resource input into Catchment Management Plans. Document History Previous Version Date Comments Number Draft 1.0 Nov 94 For comment by Deben ALF Project Team members. Draft 2.0 Jan 95 Final Draft. PEBEN GROUNDWATER UNIT: WATER RESOURCES MANAGEMENT PLAN CONTENTS 1 SU M M A R Y ..................................................................................................................... 1 1.1 Area of Study .................................................................................................... 1 1.2 Groundwater B alan c e........................................................................................ 1 1.3 Current Issues .................................................................................................... 2 1.4 Recomm endations.............................................................................................. 2 1.4.1 Licensing Policy .................................................................................. 3 1.4.2 River Flows and Environmental N eeds............................................ 3 1.4.3 River Deben Alleviation of Low Flows ......................................... 4 1.4.4 Groundwater Modelling...................................................................... 4 2 IN TRO D U CTIO N ......................................................................................................... 5 2.1 L ocation............................................................................................................... ...5 .2 .2 Current Issues .......................................................................................................5 2.2.1 Provision of Secure Water Supplies............■.........................................5 2.2.2 Protection and Improvement of the Water Environment...................6 2.2.3 Water Resources Management P o licy ...................................................7 3 DESCRIPTION ......................................................................... .................................. ...9 3.1 Hydrogeology .................................................................................................... 9 3.2 H ydrology............................................................................................................ 9 3.3 River Support ....................................................................................................10 3.4 Existing M o d e ls .................................................................................................10 4 WATER RESOURCES ........................................................................... ............13 4.1 Surface Water R esources.................................................................................. 13 4.2 Groundwater Resources ..................................................................................13 4.2.1 Hydrotechnica Resource Assessment ............................................... 13 4.2.2 Water Resources Strategy, Application of Resource Assessment................................................................ .............................14 Water Resources Planning River Deben Final Report Water Resources Management Plan February 1995 5 WATER QUALITY .....................................................................................................17 5.1 Surface Water .................................................................................................... 17 5.1.1 E.C. Fishery Directives...................................................................... 17 5.1.2 River Quality Objectives ................................................................... 17 5.1.3 National Water Council Classification ............................................ 18 5.1.4 Biological S tan d ard s............................................................................ 18 5.1.5 G e n e ra l.................................................................................................... 19 5.2 . Groundwater ...................................................................................................... 19 5.2.1 Groundwater Protection Zones (GPZ’s) ......................................... 19 5.2.2 Nitrate Vulnerable Zones (NVZ’s) ..................................................19 5.2.3 Nitrate Sensitive Areas (NSA’s ) ....................................................... 20 5.2.4 Salinity ............: .....................................................................................20 5.2.5 G e n e ra l.................................................................................................... 20 6 W ATER USE IN TH E GROUNDWATER U N IT ............................................... 21 6.1 Public Water Supply ........................................................................................21 6.1.1 Licensed A bstraction............................................................................ 21 6.1.2 Actual Abstraction ............................................................................... 21 6.1.3 Sourceworks Reliable Outputs (SRO’s ) ............................................ 22 6.1.4 Forecast Demand Growth .................; ...............................................24 6.1.5 Proposed New Sources ...................................................................... 25 6.1.6 Implications of New D evelopm ents.................................................. 26 6.2 Agriculture ......................................................................................................... 29 6.2.1 Spray Irrigation ..................................................................................29 6.2.2 General Agriculture ............................................................................ 30 6.3 In d u s tr y ................................................................................................................31 6.4 Environment .................. ......................... ..........................................................31 6.4.1 River F lo w s .................................................................................. ... 31 6.4.2 Wetland Sites ........................................................................................32 6.4.3 Saline In tru sio n .....................................................................................33 6.5 River Support ....................................................................................................33 6.6 Navigation ..........................................................................................................34 6.7 F isheries................................................................................................................ 34 6.8 Recreation and Amenity .................................................................................. 34 6.9 Effluent ................................................................................................................ 34 7 BALANCE O F RESOURCES AND DEMANDS ............................................... 37 7.1 Surface Water ....................................................................................................37 7.2 G ro u n d w ater........................*............................................................................ 38 7.3 Summary of Water Resources and Demands................................ .............. 43 Water Resources Planning River Deben Final Report Water Resources Management Plan February 1995 8 ISSUES AND O P T IO N S ..............................................................................................45 8.1 Increasing Demand for Water Abstraction, & Licensing Policy ............45 8.1.1 G roundw ater...........................................................................................45 8.1.2 Surface W a te r........................................................................................ 46 8.2 Protection and Improvement of the Environment ...................................... 46 8.3 Protection and Improvement of River Water Quality ................................ 47 8.4 River Support ................................................................................................... 48 8.5 Groundwater Modelling .................................................................................. 49 9 CO N CLU SIO N S.............................................................................................................51 9.1 Water R esources.................................................................................................51 9.2 Water Abstraction D em ands............................................................................ 51 9.3 Environmental Water D em ands...................................................................... 51 9.4 Balance of Resources