ENERGY WORKING FOR BRITAIN FOR WORKING ENERGY Wylfa Newydd Project 6.4.27 ES Volume D - WNDA Development App D8-2 - Fluvial Geomorphology Baseline Report PINS Reference Number: EN010007 Application Reference Number: 6.4.27 June 2018 Revision 1.0 Regulation Number: 5(2)(a) Planning Act 2008 Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009 Horizon Internal DCRM Number: WN0902-JAC-PAC-APP-00135 [This page is intentionally blank] Wylfa Newydd Project Horizon Nuclear Power Ltd Fluvial Geomorphology Baseline Report 60PO8007-GEO-REP-001 | V2.0 January 2018 WN03.03.01-S5-PAC-REP-00021 Fluvial G eo mor pholo gy Baseli ne Re por t Horizon Nuclea r Powe r Lt d Fluvial Geomorphology Baseline Report Wylfa Newydd Project Project no: 60PO8007 / 60PO8077 Document title: Fluvial Geomorphology Baseline Report Document No.: 60PO8007-GEO-REP-001 Revision: V2.0 Date: January 2018 Client name: Horizon Nuclear Power Ltd Client no: WN03.03.01-S5-PAC-REP-00021 Project manager: Rob Bromley Author: Sera Roberts, Katy Kemble Jacobs U.K. Limited 1180 Eskdale Road Winnersh, Wokingham Reading RG41 5TU United Kingdom T +44 (0)118 946 7000 F +44 (0)118 946 7001 www.jacobs.com © Copyright 2018 Jacobs U.K. Limited. The concepts and information contained in this document are the property of Jacobs. Use or copying of this document in whole or in part without the written permission of Jacobs constitutes an infringement of copyright. Limitation: This report has been prepared on behalf of, and for the exclusive use of Jacobs’ Client, and is subject to, and issued in accordance with, the provisions of the contract between Jacobs and the Client. Jacobs accepts no liability or responsibility whatsoever for, or in respect of, any use of, or reliance upon, this report by any third party. Document history and status Revision Date Description By Review Approved V0.1 30/01/2015 For comment Sera Andrew Rob Roberts Brookes Bromley V0.2 23/04/2015 Final for client comment Sera Katy Kemble Rob Roberts Bromley V0.3 04/2015 Final Sera Katy Kemble Rob Roberts Bromley V0.4 25/11/15 Final following proof read Steve Heidi Rob Hobbs Hutchings Bromley V1.0 10/04/17 Update (including Cycle 2 WFD data) Sera Katy Kemble Rob Roberts / Steve Bromley Hobbs V2.0 03/01/18 Update of references, main rivers and aquifers Steve Katy Kemble Rob Hobbs Bromley 60PO8007-GEO-REP-001 i Fluvial Geomorphology Baseline Report Contents Executive Summary .................................................................................................................................1 1. Introduction ..................................................................................................................................2 1.1 Overview ........................................................................................................................................2 1.2 Site description ..............................................................................................................................2 1.3 Study aims and objectives ..............................................................................................................2 2. Methodology.................................................................................................................................4 2.1 Desk study .....................................................................................................................................4 2.2 Geomorphological reconnaissance surveys ....................................................................................4 2.3 Site screening ................................................................................................................................5 3. Desk study ....................................................................................................................................6 3.1 Nant Cemlyn ..................................................................................................................................6 3.2 Afon Cafnan ...................................................................................................................................6 3.3 Afon Wygyr ....................................................................................................................................8 3.4 Tre’r Gof SSSI drains .....................................................................................................................8 3.5 Nant Cemaes .................................................................................................................................9 3.6 Other watercourses ........................................................................................................................9 4. Water Framework Directive status ............................................................................................ 10 5. Contemporary characteristics ................................................................................................... 12 5.1 Nant Cemlyn ................................................................................................................................ 12 5.2 Afon Cafnan ................................................................................................................................. 13 5.3 Afon Wygyr .................................................................................................................................. 19 5.4 Tre’r Gof SSSI Drains................................................................................................................... 20 5.5 Nant Cemaes ............................................................................................................................... 21 6. Conclusions ............................................................................................................................... 24 7. References ................................................................................................................................. 25 8. Glossary ..................................................................................................................................... 26 60PO8007-GEO-REP-001 ii Fluvial Geomorphology Baseline Report Executive Summary Horizon Nuclear Power Ltd (Horizon) is currently planning to develop a new Nuclear Power Station to the west of Cemaes, Anglesey, as identified in the National Policy Statement for Nuclear Power Generation (EN-6) [RD1]. As a Nationally Significant Infrastructure Project under the Planning Act 2008, the construction and operation must be authorised by a Development Consent Order. Jacobs UK Ltd (Jacobs) has been commissioned by Horizon to undertake a fluvial geomorphology assessment and review of physical processes information/data to inform the Development Consent Order Environmental Statement. This report summarises the baseline conditions for the fluvial geomorphology aspect of the Wylfa Newydd Project study area. Geomorphological reconnaissance surveys were undertaken in November 2014 and July 2015 to assess the baseline condition of the key watercourses potentially affected by the Wylfa Newydd Project. The reconnaissance surveys provide a record of the geomorphological conditions of the watercourses at the time of the surveys and also provide an understanding of the nature of the catchments and other associated watercourses/drainage ditches. A photographic record of the general character of the watercourses is included in this report. This report specifically details the results from the reconnaissance surveys and a desk study of available information, including map analysis (historical and contemporary), geology, soils and aerial photography. The baseline assessment concluded that the fluvial watercourses had typically been historically artificially straightened and possibly dredged for agricultural drainage purposes. The survey noted that they often demarked field boundaries and had little or no vegetated riparian buffer between the channel and cultivated land. The majority of the channels had inputs from several diffuse and point sources of fine sediment, primarily from animal poaching and inputs from field drains. 60PO8007-GEO-REP-001 1 Fluvial Geomorphology Baseline Report 1. Introduction 1.1 Overview Horizon Nuclear Power Ltd. (Horizon) is currently planning to develop a new Nuclear Power Station to the west of Cemaes, Anglesey, as identified in the National Policy Statement for Nuclear Power Generation (EN-6) [RD1]. As a Nationally Significant Infrastructure Project under the Planning Act 2008, the construction and operation must be authorised by a Development Consent Order. Jacobs UK Ltd (Jacobs) was commissioned by Horizon to prepare a fluvial geomorphology baseline to inform the Environmental Impact Assessment. This report details the geomorphological baseline for all the watercourses within the Wylfa Newydd Project study area (hereafter referred to as the ‘study area’) (see figure 1.1) with the exception of two watercourses (see section 2.3). This includes a desk study and geomorphological reconnaissance surveys. 1.2 Site description The Wylfa Newydd Development Area includes the Power Station Site and surrounding area to be used for the construction and operation of the Power Station. It is bounded to the north by the coast and the Existing Power Station. To the east, it is separated from Cemaes by a narrow corridor of agricultural land. The A5025 and residential properties define part of the south-east boundary, with