( THE M4 CORRIDOR AROUND NEWPORT SCHEME )

Transcription

1 PUBLIC INQUIRY IN THE MATTER OF THE HIGHWAYS ACT 1980 AND THE ACQUISITION OF LAND ACT 1981 AND IN THE MATTER OF: THE M4 MOTORWAY (JUNCTION 23 (EAST OF MAGOR) TO WEST OF JUNCTION 29 (CASTLETON) AND CONNECTING ROADS) AND THE M48 MOTORWAY (JUNCTION 23 (EAST OF MAGOR) CONNECTING ROAD) AND THE LONDON TO FISHGUARD TRUNK ROAD (EAST OF MAGOR TO CASTLETON)) COMPULSORY PURCHASE ORDER and- THE M4 MOTORWAY (JUNCTION 23 (EAST OF MAGOR) TO WEST OF JUNCTION 29 (CASTLETON) AND CONNECTING ROADS) AND THE M48 MOTORWAY (JUNCTION 23 (EAST OF MAGOR) CONNECTING ROAD) SCHEME and- THE M4 MOTORWAY (WEST OF MAGOR TO EAST OF CASTLETON) AND THE A48(M) MOTORWAY (WEST OF CASTLETON TO ST MELLONS) (VARIATION OF VARIOUS SCHEMES) SCHEME and- THE LONDON TO FISHGUARD TRUNK ROAD (EAST OF MAGOR TO CASTLETON) ORDER and- THE M4 MOTORWAY (JUNCTION 23 (EAST OF MAGOR) TO WEST OF JUNCTION 29 (CASTLETON) AND CONNECTING ROADS) AND THE M48 MOTORWAY (JUNCTION 23 (EAST OF MAGOR) CONNECTING ROAD) AND THE LONDON TO FISHGUARD TRUNK ROAD (EAST OF MAGOR TO CASTLETON) (SIDE ROADS) ORDER 201- ( THE M4 CORRIDOR AROUND NEWPORT SCHEME ) SUMMARY PROOF OF EVIDENCE ON LAND DRAINAGE AND WATER LEVEL MANAGEMENT OF MATEUSZ BAJOWSKI FOR THE NATURAL RESOURCES BODY FOR WALES

2 Contents 1. Introduction 2. Relevant Background 3. Site Context 4. Issues 4.1. Drainage Strategy 4.2. Reen Mitigation Strategy 4.3. Water Level Management 4.4. Collister Pill Pumping Station 4.5. Water Treatment Areas 4.6. Drainage Network Management and Maintenance 4.7. CDM Regulations 4.8. Land Drainage Consents 5. Comments on Alternative Routes 6. Conclusions Page 2 of 13

3 1. INTRODUCTION 1.1. My name is Matt Bajowski and I am (NRW) Internal Drainage District (IDD) Engineer for the Caldicot and Wentlooge Levels Drainage District since April Prior to this, I was Engineer to the Board of the Caldicot and Wentlooge Levels Internal Drainage Board (IDB), from February 2012, having started with this IDB as Assistant Engineer in June I gained an Engineering Degree in the field of Environmental Protection from the Agricultural University of Wroclaw, Poland, in In 2011 obtained a Higher National Certificate in Civil Engineering from the University of Wales, Newport. I have been a professionally qualified Civil Engineer (Technician Member) of the Institution of Civil Engineers (ICE) since I was awarded the Ben Barr Award in 2012 as the best newly qualified Technician Member of ICE in Wales, based on my work in the then IDB My experience covers: water level management, flood risk management, civil engineering works within environmentally sensitive areas, development control within flood risk areas, sustainable urban drainage systems, regular presentations to various boards and negotiations with developers regarding the adoption of assets including calculations of commuted sum and drafting agreements covering maintenance of new watercourses created within internal drainage districts During the past eight years I have also worked for the following IDBs: Caldicot and Wentlooge Levels IDB; North Somerset Levels IDB; Lower Wye IDB; River Lugg IDB; and, Powysland IDB. 2. RELEVANT BACKGROUND 2.1. The figure below shows the boundaries of the Caldicot and Wentlooge Levels Internal Drainage District (IDD). Page 3 of 13

4 2.2. The IDD area covers a strip of low-lying land that is approximately 19 miles along and 2 miles wide, running eastwards from the mouth of the River Rhymney outside Cardiff to the mouth of the River Wye at Chepstow. The sea defences of the Severn Estuary form its southern boundary and the rising uplands of East Glamorgan and Monmouthshire its northern boundary The IDD area is split into two principal parts and hydrological units: The Caldicot Level occupying 7,100 hectares to the east of the city of Newport; and, the Wentlooge Level 3,400 hectares to the west. The whole area lies below sea level, some parts are up to four metres below mean high tide level, and has a catchment of approximately 25,940 hectares year. Gwent Levels Drainage Network 2.4. The complex drainage system starts with the grips. These take water into field ditches, for which landowners are the responsible managing; and others into larger reens, the management of which is exercised under permissive Page 4 of 13

5 powers of NRW s IDD Team. The reens then discharge into main rivers, also maintained by NRW under permissive powers. Main rivers discharge into the Severn Estuary during low tide. This drainage system has been used to control water on the Gwent Levels for thousands of years, the first sea defences having been built in Roman times. NRW s witnesses giving evidence to the inquiry on the Gwent Levels Site of Special Scientific Interest (SSSIs) and landscape matters provide further information regarding the ecological and historical importance of reens Across the Gwent Levels, more than 6,000 residential properties and business units rely on the network of reens for discharge of their surface run off roof water. As ground conditions are not suitable for the use of soakaways, in light of absence of other infrastructure, the network of reens is their best option for surface water disposal The network of ditches, reens and main rivers is also a source of drinking water and field boundaries for livestock kept on the Gwent Levels Local infrastructure including roads and buildings is dependent on water levels within reens which during dry summer months increase ground stability preventing slippages of embankments and structural damage to buildings. Water Level Management 2.8. Water levels are actively managed by NRW with the aid of nearly 200 control structures spread across approximately 250km of reens and main rivers in order to provide water in summer for conservation, agriculture and ground stability reasons, and all year round to manage flood risk NRW was involved in numerous pre-application meetings with the Welsh Government s consultants to develop this area of work, around the key issue of our continued ability to undertake water level management within the Caldicot and Wentlooge Levels Internal Drainage District. However, a number of concerns over water level management remain. Page 5 of 13

6 2.10. Under the provisions of the Land Drainage Act 1991 ( the 1991 Act ) [NRW 2.1], NRW has a duty to exercise general supervision over all matters relating to the drainage of land within its Drainage District. Further to this byelaws, made under Section 66 of the 1991 Act [NRW 3.1], control works carried out and activities undertaken by others affecting watercourses within these Drainage Districts NRW IDD Reens are ordinary watercourses under the direct operational control of NRW. NRW exercises permissive powers to carry out maintenance and improvement works on ordinary watercourses within Internal Drainage Districts in Wales The Byelaws also require that persons obtain consent for activities in or adjacent to NRW IDD reens and on their floodplains. 3. SITE CONTEXT 3.1. NRW delivers water level management within the IDD area. During the summer months higher Summer Penning Level (SPL) is maintained for multiple reasons, including agricultural and nature conservation purposes linked to the Gwent Levels SSSIs Active Water level management, for a variety of purposes, requires flexibility to move water around, with the aid of water level control structures. During winter months water levels are lowered to Winter Penning Levels (WPL) with the aid of control structures in order to maximise attenuation available within the network of reens in readiness for wet period, but also to flush nutrientrich waters, which accumulate in the reen system over the summer, from the system. The reens are re-filled with less nutrient-rich water at the end of winter Current practices would need to be replicated within the new proposed sections of the drainage network. This would require new water level control Page 6 of 13

7 structures along with resources needed to maintain and operate them in future years Regular maintenance of the reens and main rivers plays a crucial role in delivery of water level management, including flood risk management. NRW undertakes the clearance of vegetation of aquatic weed using both its own employees and external contractors. All activities are regulated and take place during time frames governed by environmental restrictions NRW guidance regarding rights and responsibilities of riverside ownership in Wales replaced the Living on the edge document written by the Environment Agency [NRW 3.1]. The NRW guidance provides clarity on the responsibility for maintenance. NRW, as the IDD does not have statutory responsibility for reen management and maintenance, but exercises permissive powers in this regard. The responsibility, in law, remains with the riparian owners. 4. ISSUES 4.1 Drainage Strategy Under the M4 Corridor around Newport scheme ( the scheme ) it is proposed that surface water drained from the completed highway would primarily occur via grass-lined channels to Water Treatment Areas (WTAs) prior to discharge to water courses within the Caldicot and Wentlooge Levels IDD, at Greenfield rates. In relation to its IDD functions, NRW supports this approach. 4.2 Reen Mitigation Strategy In respect of its IDD functions, NRW considers this would be satisfactory mitigation. Please refer to the Proof of my colleague, Jessica Poole, with respect to NRW s view with respect to the Gwent Levels SSSIs [NRW 1.5.1] From the perspective of its IDD functions, NRW is satisfied with the proposed dimensions of the replacement reens and ditches as set out in the ES [ES, Page 7 of 13

8 Volume 3, Appendix 2.2 Drainage Strategy, paras and 8.1.2]. However, NRW observes that this differs from the details given in the Buildability Report [ES, Volume 3, Appendix 3.1, 4.2.2]. 4.3 Water Level Management NRW would continue to need to manage water levels across the IDD, which would best be undertaken through the use of tilting weirs or similar stainless steel control structures such as pen stocks or double leaf gates The addition of new water level control structures is marked on plans submitted to support the ES and the addition of Commitment 162 to the Register of Environmental Commitments (presented as Appendix SR18.1 to the December Environmental Statement Supplement [WG ]) partially satisfies NRW that this would enable it to continue effective water level management within the IDD. NRW also requires commitment to provide resources to cover the cost of operating the tilting weirs and therefore delivery of water level management to be made as part of the Statement of Commitments. This is crucial to our continued ability to undertake effective water level management within the IDD and lies at the heart of NRW s objection on drainage grounds In addition to water level control structures, identified and marked as part of the ES, it has been acknowledged by Welsh Government s consultants, that there might be a need for more structures to be introduced once the scheme is fully operational to address issues with water level management. NRW welcomes that this issue has now been addressed at Condition 163 of the Register of Environmental Commitments [[WG ]. 4.4 Collister Pill Pumping Station NRW requires reassurance that works associated with the scheme s drainage and reen mitigation strategies would not increase the required use of the Collister Pill (Main River) pumping station. Page 8 of 13

9 4.5 Water Treatment Areas (WTAs) WTA 12a This watercourse has been modified in recent years by the landowner. NRW raised a concern in this regard and advised that investigation be undertaken to assess the suitability and feasibility of this proposal. WTA 12b Both the WTA and the brook are located outside the IDD area. Vurlong Reen does not appear on NRW records. Monmouthshire County Council is the Lead Local Flood Authority (LLFA) for this area and NRW has asked for clarification from Welsh Government as to how water from WTA 12b would be connected to the network of reens. 4.6 Drainage Network Management and Maintenance NRW requires confirmation of maintenance and management responsibility in perpetuity for the new reens, ditches, culverts and water control It has been intimated by the Welsh Government s consultants, during a recent meeting with NRW in September 2016, that NRW could take on this management responsibility of the new aspects of the drainage system. Significant costs would be associated with taking on responsibility for this work NRW requires that acceptable arrangements are in place in order for it to be satisfied that appropriate management will occur NRW s position is that it is imperative that the outstanding uncertainty surrounding responsibility for maintenance of the replacement reens and ditches is resolved. Page 9 of 13

10 4.6.5 NRW is concerned that no reference is made in the Drainage Strategy published with the scheme to proposals for ongoing maintenance of new culverts, including routine desilting and reactive blockage removal. 4.7 Construction (Design and Management) Regulations 2015 (CDM Regulations 2015) NRW requires reassurance that its ability to undertake routine and emergency response within and adjacent to this construction site would be maintained throughout any construction period Before the commencement of any construction works, NRW would require written agreement as to the arrangements which will need to be put in place to ensure that it can continue to undertake a number of its essential activities, including: routine reen, ditch and flood risk management structure management and maintenance; emergency works, such as blockage removal and repairs to defences; wider compliance and enforcement work within NRW s remit, not directly related to the M4 construction works. 4.8 Land Drainage Consents Land drainage consent would be required for all culverts, new channels, control structures, lagoons and outfalls. NRW is responsible for land drainage consenting on ordinary watercourses within the Caldicot and Wentlooge Land Drainage District. Outside of this area, responsibility falls on the relevant local authority. NRW has advised that local authorities views are sought NRW has also advised that land drainage consents may also be required outside of the main footprint of the proposed road (e.g. where works are required for access roads) The set of drawings within Annex 1 [Proposed Reen Crossings, figure 4.2.2] do not meet NRW s requirements and would not meet standards required as part of any Land Drainage Consent application. Page 10 of 13

11 4.8.4 Furthermore, these drawings have not taken account of NRW s previously submitted design requirements, which it provided to Welsh Government s consultants for the scheme on 14 May While NRW welcomes the consideration that has been given to its design requirements [Appendix 2.2, Drainage Strategy and Appendix 2.3 Reen Mitigation Strategy], it remains concerned by the discrepancy within the overall ES. 5 Comments on alternative route 5.1 Although NRW has carefully considered the information in the ES relating to this proposed route, a comprehensive assessment of the Blue Route or any other alternative route has not been undertaken. 5.2 The Blue Route [WG 4.5.4] would have very limited impact on NRW s ability to provide water level management. 6 Conclusions 6.1 Construction of the M4 Corridor around Newport could have an adverse effect on NRW s ability to provide water level management service and undertake regular maintenance of its network of reens and main rivers unless adequate provision is made for its impact on the system of reens present in much of the area affected by the proposal. 6.2 Formal commitments are required, through the Statement of Commitments, regarding provision of sufficient resources to introduce additional water level control structures. Such commitment includes an assurance that the scheme will not increase the cost of running Collister Pill pumping station 6.3 NRW has identified technical issues in respect of two Water Treatment Areas (WTA 12a & WTA 12b). 6.4 Arrangements for future maintenance of new elements of the drainage network introduced as part of the scheme would have to be put in place to Page 11 of 13

12 ensure continuity of current standard of maintenance and continued ability to provide active water level management. 6.5 Access arrangements have to be agreed with NRW regarding access to NRW s assets on the Gwent Levels during construction phase in light of CDM Regulations. 6.6 Land Drainage Consents will have to be applied for in compliance with the 1991 Act. 6.7 None of the above commitments and/or assurances had been provided by the Welsh Government at the time of filing this proof of evidence. DECLARATION I confirm that the facts and matters referred to in this report are true to the best of my knowledge and belief. The opinions I have expressed represent my true and complete professional opinions on the matters to which they refer. Matt Bajowski EngTech MICE Date: 7 February 2017 APPENDICES 1. Land Drainage Act 1991 [NRW 2.1] 2. Caldicot and Wentlooge Levels IDD Byelaws [NRW 3.1] 3. NRW guidance regarding rights and responsibilities of riverside ownership in Wales [NRW 3.2] Page 12 of 13

13 4. Land Drainage Consents Guidance Notes for Applicants, Natural Resources Wales [NRW 3.3] Page 13 of 13