Lower Umkhomazi Bulk Water Supply System – Water Supply Scheme in Kwazulu-Natal
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LOWER UMKHOMAZI BULK WATER SUPPLY SYSTEM – WATER SUPPLY SCHEME IN KWAZULU-NATAL ENVIRONMENTAL IMPACT ASSESSMENT REPORT 14/12/16/3/3/2/1030 FEBRUARY 2018 DRAFT PREPARED FOR: UMGENI WATER Title and Approval Page Lower uMkhomazi Bulk Water Supply System – Water Supply Scheme in Project Name: KwaZulu-Natal Report Title: EIA Report Authority Reference: 14/12/16/3/3/2/1030 Report Status: Draft Applicant: Umgeni Water Prepared By: Nemai Consulting +27 11 781 1730 147 Bram Fischer Drive, +27 11 781 1731 FERNDALE, 2194 [email protected] PO Box 1673, SUNNINGHILL, www.nemai.co.za 2157 Report Reference: 10579-20171117-Draft EIA Report R-PRO-REP|20170216 Authors: S. Gerber and D. Henning This Document is Confidential Intellectual Property of Nemai Consulting C.C. © copyright and all other rights reserved by Nemai Consulting C.C. This document may only be used for its intended purpose LUBWSS – Water Supply Scheme EIA Report Draft Amendments Page Amendment Date: Nature of Amendment Number: 19/02/2018 Draft Report for 30-Day Authority and Public Review 01 LUBWSS – Water Supply Scheme EIA Report Draft Executive Summary The current water resources supplying the South Coast of KwaZulu-Natal are insufficient to meet the projected water demands. The Lower uMkhomazi Bulk Water Supply System is the recommended augmentation option for the existing Upper and Middle South Coast Supply area. Therefore, Umgeni Water propose to construct the Lower uMkhomazi Bulk Water Supply System – Water Supply Scheme in order to increase the assurance of water supply. The project area is situated in the eThekwini Metropolitan Municipality in KwaZulu-Natal. The proposed scheme will supply water to the Middle and Upper South Coast areas (Hibberdene to Amanzimtoti) within KwaZulu-Natal. The proposed developments are located approximately 10km north of Scottburgh. Locality Map The overall Lower uMkhomazi Bulk Water Supply System will consist of the following project components: • The Ngwadini Weir and abstraction works to fill the Ngwadini Off-channel Storage Dam during summer periods of excess flow; - i – February 2018 LUBWSS – Water Supply Scheme EIA Report Draft • The Ngwadini Off-channel Storage Dam, with a capacity of 10 million m3, and outlet infrastructure to release water back into the river and augment low flow periods; • A second abstraction downstream at the Goodenough Weir site to abstract the raw water for delivery to the Water Treatment Plant; • A pump station to pump water from the Goodenough abstraction to the Water Treatment Plant via; • A short rising main and 7km gravity main with; • A break pressure tank that also serves as a raw water storage reservoir; • Hydrocyclones before the pump station and Water Treatment Plant to remove sediments during periods of higher turbidity river flows and reduce the Water Treatment Plant residual (“sludge”); • A 100 Ml/d Water Treatment Plant in the town of Craigieburn; and • A potable gravity water pipeline from the Water Treatment Plant to Quarry Reservoir, the potable water delivery and tie-in point on the South Coast Pipeline. The requirements in terms of the National Environmental Management Act (Act No. 107 of 1998) for the Lower uMkhomazi Bulk Water Supply System project components are detailed below. Lower uMkhomazi Bulk Water Supply System Components and National Environmental Management Act (Act No. 107 of 1998) Requirements National Environmental Management Act No. Project Component Requirements 1 Ngwadini weir and Authorisation previously received in terms of the abstraction works to fill the Environment Conservation Act (Act No. 73 of 1989). Ngwadini Off-channel However, it was confirmed in consultation with Storage Dam during KwaZulu-Natal Department of Economic summer periods of excess Development, Tourism and Environmental Affairs flow. that a new Basic Assessment would need to be conducted due to changes in location and design. A separate Application will be submitted to Department of Environmental Affairs. Water 2 Ngwadini Off-channel Authorisation was previously received in terms of Resource Storage Dam, with a Environment Conservation Act (Act No. 73 of 1989). Development capacity of 10 million m3, However, it was confirmed in consultation with and outlet infrastructure to KwaZulu-Natal Department of Economic release water back into the Development, Tourism and Environmental Affairs river and augment low flow that an amendment to the authorisation would need periods. to be applied for due to slight changes in design. A separate Environmental Authorisation Amendment Application will be submitted to KwaZulu-Natal Department of Economic Development, Tourism and Environmental Affairs. 3 Water Supply Scheme – Abstraction Works, This will be the focus of this Application, where a Conveyance Infrastructure and Water Scoping and Environmental Impact Assessment Treatment Plant process needs to be conducted. The Environmental Impact Assessment Phase focuses on the Water Supply Scheme which forms part of the overall Lower uMkhomazi Bulk Water Supply System. - ii – February 2018 LUBWSS – Water Supply Scheme EIA Report Draft Nemai Consulting was appointed by the Umgeni Water as the Environmental Assessment Practitioner to undertake the Environmental Impact Assessment for the Lower uMkhomazi Bulk Water Supply System – Water Supply Scheme. Alternatives to be assessed as part of the Environmental Impact Assessment process are two Water Treatment Plant site alternatives, and the resulting gravity main route to the existing quarry reservoir. Of the two sites considered, Site 2 is the preferred site from a hydraulic perspective, due to the natural topography of the site allowing the works to be gravity fed, with minimal earthworks. The EIA Report provides a general description of the status quo of the receiving environment in the project area, and also provides local and site-specific discussions on those environmental features investigated by the respective specialists. This allows for an appreciation of sensitive environmental features and possible receptors of the effects of the proposed project. The study area includes the entire footprint of all the project components, which includes the construction domain and surrounding receiving environment. The receiving environment is assessed and discussed in terms of the following: • Climate; • Geology and Soils; • Geohydrology; • Topography; • Surface Water; • Flora; • Fauna; • Socio-economic Environment • Land Use • Existing Infrastructure and Structures; • Services; • Heritage; • Air Quality; • Noise; and • Visual Quality. The following specialist studies were undertaken during the Environmental Impact Assessment to inform the best alternative for the project: • Terrestrial Biodiversity Report; • Aquatic Assessment and Wetland Delineation; • Socio-Economic Impact Assessment; • Phase 1 Heritage Impact Assessment; - iii – February 2018 LUBWSS – Water Supply Scheme EIA Report Draft • Estuarine Specialist Study; and • Sediment Impact Specialist Study. The information obtained from the respective specialist studies was incorporated into the Environmental Impact Assessment report in the following manner: 1. The information was used to complete the description of the receiving environment in a more detailed and site-specific manner; 2. A summary of each specialist study is provided, focusing on the approach to the study, key findings and conclusions drawn; 3. The specialists’ impacts assessment, and the identified mitigation measures, were included in the overall project impact assessment; 4. The evaluations performed by the specialists on the alternatives of the project components were included in the comparative analysis to identify the most favourable option; 5. Specialist input was obtained to address comments made by Interested and Affected Parties that related to specific environmental features pertaining to each specialist discipline; 6. Salient recommendations made by the specialists were taken forward to the final Environmental Impact Assessment Conclusions and Recommendations; and 7. The assumptions and limitations identified in each study were noted. The Environmental Impact Assessment Report assessed the pertinent environmental impacts that could potentially be caused by the proposed project during the pre-construction, construction and operational phases of the project. Impacts were identified as follows: • An appraisal of the project activities and components; • Impacts associated with listed activities contained in Government Notice No. R. 983, R. 984 and R. 985 of the 2014 Environmental Impact Assessment Report Regulations, as amended (07 April 2017), for which authorisation has been applied for; • An assessment of the receiving biophysical, social, economic and built environment; • Findings from specialist studies; • Issues highlighted by environmental authorities; and • Comments received during public participation. The impacts and the proposed management measures are discussed on a qualitative level and thereafter quantitatively assessed by evaluating the nature, extent, magnitude, duration, probability and ultimately the significance of the impacts. The assessment considered impacts before and after mitigation, where in the latter instance the residual impact following the application of the mitigation measures is evaluated. - iv – February 2018 LUBWSS – Water Supply Scheme EIA Report Draft The proposed mitigation of the impacts associated with the project includes specific measures identified by the technical team (including engineering