River Lugg SSSI Restoration Technical Report Draft for Comment and Consultation
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River Lugg SSSI Restoration Technical Report Draft for Comment and Consultation January 2015 Revision 2 Document Control Sheet BPP 04 F8 Version 16; October 2013 Project: Wye and Lugg SSSI Restoration Client: Environment Agency Project No: B228B001 Document title: River Lugg SSSI Restoration – Technical Report Ref. No: Originated by Checked by Reviewed by NAME NAME NAME ORIGINAL Katy Kemble Helena Parsons Helena Parsons NAME As Project Manager I confirm that the INITIALS Approved by above document(s) have been subjected to Andy Lee Jacobs’ Check and Review procedure and that I approve them for issue DATE 1/09/14 Document status: First draft REVISION NAME NAME NAME 1 Katy Kemble Alison Flynn Alison Flynn NAME INITIALS Approved by As Project Manager I confirm that the Helena Parsons above document(s) have been subjected to Jacobs’ Check and Review procedure and that I approve them for issue DATE Nov 2014 Document status: First revision for client comment REVISION NAME NAME NAME 2 Katy Kemble Sera Roberts Helena Parsons NAME INITIALS Approved by As Project Manager I confirm that the above document(s) have been subjected to Helena Parsons Jacobs’ Check and Review procedure and that I approve them for issue DATE Jan 2015 Document status: Draft for consultation Jacobs U.K. Limited This document has been prepared by a division, subsidiary or affiliate of Jacobs U.K. Limited (“Jacobs”) in its professional capacity as consultants in accordance with the terms and conditions of Jacobs’ contract with the commissioning party (the “Client”). Regard should be had to those terms and conditions when considering and/or placing any reliance on this document. No part of this document may be copied or reproduced by any means without prior written permission from Jacobs. If you have received this document in error, please destroy all copies in your possession or control and notify Jacobs. Any advice, opinions, or recommendations within this document (a) should be read and relied upon only in the context of the document as a whole; (b) do not, in any way, purport to include any manner of legal advice or opinion; (c) are based upon the information made available to Jacobs at the date of this document and on current UK standards, codes, technology and construction practices as at the date of this document. It should be noted and it is expressly stated that no independent verification of any of the documents or information supplied to Jacobs has been made. No liability is accepted by Jacobs for any use of this document, other than for the purposes for which it was originally prepared and provided. Following final delivery of this document to the Client, Jacobs will have no further obligations or duty to advise the Client on any matters, including development affecting the information or advice provided in this document. This document has been prepared for the exclusive use of the Client and unless otherwise agreed in writing by Jacobs, no other party may use, make use of or rely on the contents of this document. Should the Client wish to release this document to a third party, Jacobs may, at its discretion, agree to such release provided that (a) Jacobs’ written agreement is obtained prior to such release; and (b) by release of the document to the third party, that third party does not acquire any rights, contractual or otherwise, whatsoever against Jacobs and Jacobs, accordingly, assume no duties, liabilities or obligations to that third party; and (c) Jacobs accepts no responsibility for any loss or damage incurred by the Client or for any conflict of Jacobs’ interests arising out of the Client's release of this document to the third party. Executive Summary Jacobs was commissioned by the Environment Agency to produce separate Technical Reports for the restoration of the River Lugg and the Lower Wye. In addition, Management Reports to complement each Technical Report were also produced by Jacobs. This is a Technical Report on the geomorphological assessment and ecological interpretation of the Lower Lugg. The River Lugg is a major tributary of the River Wye, crossing both the Welsh and English borders. The River Lugg is designated as a Site of Special Scientific Interest (SSSI) in England. The River Lugg from Hope-under-Dinmore south is also designated as a Special Area of Conservation (SAC) (River Wye/Afon Gwy SAC; EU code UK0012642) under the Habitats Directive. The River Lugg is a cross- boundary catchment straddling the Welsh-English border flowing eastwards from its source at Pool Hill in Powys, Wales through the towns of Presteigne and Leominster, turning south where it reaches its confluence with the River Wye at Mordiford near Hereford. The river shows a good example of transitional river type, with both upland and lowland river morphologies represented. Natural England has subdivided the River Lugg SSSI into four management units, all of which are assessed to be in ‘unfavourable condition’. There are also two Water Framework Directive water bodies within the English section of the River Lugg, one of which is of poor ecological status and the other good ecological status. This report is required to assess the current geomorphological condition and the main physical pressures on the Lower Lugg to inform a Management Report that will provide suggestions to help achieve favourable condition in each of the management units and the River Wye SAC. A detailed desk study was conducted for the River Lugg catchment, providing an understanding of the hydrology, historical processes, amenity value, water resources, ecology and the geomorphological background. The desk study identified gaps in the data record, which was used to inform the targeted selection of field survey sites. The initial field surveys were undertaken during January and February 2014, but due to adverse weather conditions and flooding not all sites could be surveyed. As a result further surveys were undertaken during October 2014 to complete the field data collection component of this project. The surveys consisted of a combination of bespoke fluvial audits; stream reconnaissance surveys and spots check surveys of the river reaches. Spot check surveys were typically undertaken to either ground truth data from previous surveys or where access was limited due to intemperate conditions or issues with land access. During the survey, modifications to the natural geomorphology and habitat quality of the river and riparian zone were noted along with any land-use pressures and impacts observed within the river reaches. The data was recorded in the field using mobile mapping technology. The main findings from the Technical Report have shown that weirs are a major impact on the natural functioning of the Lower Lugg. Major flood defences are also present through Leominster. Outside of these high impact modifications to both the channel and banks, the Lower Lugg is a relatively natural river and although sections have been historically modified, there is evidence of natural recovery in some reaches. Most pressures on habitat suitability along the Lower Lugg include the following: River Lugg Technical Report_DraftForConsultation Weirs – presenting a barrier to longitudinal and lateral sediment and flow dynamics as well as fish migration. Weirs also impound water resulting in alteration to flow types and in-channel and marginal habitats. Historic channel realignment. Bank reinforcement – preventing geomorphological processes from occurring and removing a sediment source. Poaching from livestock. Degradation of the riparian zone – which may lead to accelerated bank erosion, reduced channel shading and increased stream water temperatures, and increased potential for diffuse sediment and pollutants to enter the river. Invasive non-native species (currently already being addressed outwith this restoration plan). Restoration of individual management units will contribute to the River Lugg SSSI and River Wye SAC achieving ‘favourable condition’. Based on the desk study and site surveys, the Lower Lugg has been divided into 26 reaches and assigned a restoration category. The restoration categories have been decided upon as follows: Significant channel restoration (3 reaches): Major works required such as removal of extensive bank reinforcement or weir removal/modification. Assisted natural recovery (2 reaches): Minor works required such as removal of minor channel structures and or naturalisation of bank profiles to remove channel resectioning. Implementation of bioengineering techniques to improve modified channels, embankment breaching to improve channel cross-sections, flood storage, wet woodland and backwater creation. Natural recovery/conserve and protect (3 reaches): Allow current natural processes to continue. No intervention is required or minor improvements such as riparian zone replenishment could be implemented. Riparian zone management (18 reaches): Grazing management, buffer strips, tree planting and/or tree management to improve sediment budgets or encourage natural temperature control. The Environment Agency and Natural England recognise the challenges linked to the river faced by landowners and managers throughout the catchment. The Statutory Bodies recognise that the successful implementation of a restoration plan will require effective and positive engagement with all stakeholders. The restoration actions in the accompanying management report are suggested as a means to achieve favourable condition of the SSSI and SAC. Both the River Lugg Technical Report and Management Report will inform future decision making by statutory bodies and should help the targeting and uptake of agri-environmental schemes, thus encouraging farmers to seek financial advice to adapt their current practices. Given that the River Lugg is a tributary of the River Wye and forms part of the wider Wye catchment area, this Technical Report and associated restoration Management Plan will link to the Wye catchment plan being developed by the Wye and Usk Foundation (WUF). The WUF catchment plan will look at all aspects of the catchment and incorporate this Lugg River Restoration Plan (RRP) and other complementary initiatives for the SSSI/SAC such as the Nutrient Management Plan.