TECHNICAL REPORT JANUARY cell: tel: (028) fax: POBox 1752 Hermanus 7200

Transcription

1 APPLICATION FOR A WATER USE LICENCE IN TERMS OF SECTION 21(a) OF THE NATIONAL WATER ACT, (ACT 36 OF 1998): TAKING WATER FROM A RESOURCE FOR LANDSCAPING IRRIGATION AND POTABLE USE ON ERF (ERVEN 5116 and 5117), GORDONS BAY, CAPE TOWN TECHNICAL REPORT JANUARY 2018 cell: tel: (028) fax: amanda@phsconsulting.co.za POBox 1752 Hermanus 7200 F ynbos l a n d C C t /a P H S C onsult ing Re g / /2 3

2 Contents 1. Background information: Legislation related to this application: Description of catchment: Groundwater use on site: Section 27 Motivation for WULA Public consultation on WULA List of Appendices attached to technical report: A. Water quality results, Geohydrological Borehole Siting report, Yield test, Existing GA B. Stormwater Management plan, Landscaping and Irrigation plans, Stormwater layout plan, Approved SDP, RO plant layout and reticulation layout for site 2

3 1. Background information: The Applicant for this Water Use Licence (WULA) is Shoprite Checkers (Pty) Ltd. Shoprite Checkers (Pty) Ltd is currently completing construction of a shopping centre development (see Figure 1 and 2) on Erf (made up of Erven 5116 and 5117), Gordons Bay, and will require water in future for irrigation of landscaping and for potable use in the shopping centre. It is proposed that this source of water be from a newly drilled borehole on site. The site is located on Sir Lowry s Pass Road, Firlands, with the surrounding area mostly comprised of housing developments. The Site Development Plan (SDP) in Appendix B shows the shopping centre layout, and the Landscaping and Irrigation plans (also Appendix B) provide more detail on the proposed landscaping layout and the required irrigation. The water quality and yield results for the borehole are provided in Appendix A. From the quality test results it can be seen that the water is fit for irrigation (note quality test performed against drinking water standard SANS 241-1: 2015), with a yield of litres per hour. In order to use the water as potable on site it will have to be treated by a Reverse Osmosis (RO) process.the proposed design of the water treatment plant to enable potable use inside the centre is included in Appendix B. The centre already has a General Authorisation (GA) of 1 054m 3 /annum in place for the use of the water from the borehole to establish initial landscaping on site (see Appendix A). The WULA, once authorised, will replace the GA for the site. Figure 1: Location of shopping mall site 3

4 Figure 2: Location of Erf (made up of Erven 5116 and 5117) 2. Legislation related to this application: This WULA Application is in terms of section 21(a) of the National Water Act, Act 36 of 1998: S21. For the purposes of this Act, water use includes - (a) taking water from a water resource; S21(a) refers to the groundwater abstraction to be used for irrigation and potable use on site. The following forms accompany this application (Appendix C): 1. DW DW DW DW DW DW902 For the purposes of the Public participation process on the technical report information relating to Appendix C and D will only be included in the final report to DWS. 4

5 3. Description of catchment: The site, Erf lies within quaternary catchment G22K within the Berg-Olifants Water Management Area (see Figure 3). According to the borehole siting report (Appendix A) the site is underlain by quartzose greywacke and mudrock of the Tygerberg Formation (Malmesbury Group). The aquifer underneath the site is classified as fractured with an average borehole yield potential of litres per second. The verified yield of the borehole is within range at 0.97 litres per second (see Appendix A). There are no registered (WARMS) boreholes indicated within the 1 km radius of the mall. There is an artificial wetland approximately 110m to the North of the site boundary, with no rivers or other surface water resources in close proximity to the site. Farm 90/587 Figure 3: Erf proximity to wetlands (purple = artificial) There are two small retention ponds on site (see SDP in Appendix B) for stormwater management: Pond 1 = 152m 3 (Southern corner of property); Pond 2 = 130m 3 (Northern corner of property). The site falls within a Mediterranean climate with a winter rainfall, with the Mean Annual Precipitation (MAP) measured for the area as approximately 570 mm per annum. It receives the lowest rainfall (16mm) in February and the highest (133mm) in June. The monthly distribution of average daily maximum 5

6 temperatures shows that the average midday temperatures for Gordons Bay range from 15.3 C in July to 24.7 C in February. Prevailing winds are south-easterly during the summer and north-westerly during the winter. 4. Groundwater use on site: The abstraction point for the groundwater will be from a borehole (see Appendix A for siting report and Figure 5 for position of borehole on site). As can be seen in Figure 4 the borehole is housed in a manhole under the loading yard access with water pumped to the holding tanks (five 10m 3 holding tanks) at an average rate of litres per hour. Two holding tanks are dedicated to irrigation and three to potable supply. The borehole pump automatically switches off/on through a series of float switches in the holding tanks. From the irrigation holding tanks the irrigation mainline is permanently pressurised at 6 Bar via a water booster pump connected to the tanks. The site reticulation is illustrated in Appendix B. Figure 4: Borehole installation inside manhole Of the anticipated 31m 3 /day abstracted for use on site, 26m 3 /day will pass through a Reverse Osmosis (RO) plant. The layout for the treatment plant is provided in Appendix B. Of the 26m 3 /day treated, approximately 30% is disposed of to sewer as brine (7,5m 3 /day) resulting in 18.5m 3 /day from the treatment plant at potable standard. The untreated 5m 3 /day is blended with 5m 3 of treated water and used for irrigation, leaving 13,5m 3 /day available for potable use within the centre. Total water abstracted per day = 31m 3 /day Total irrigation use per day = 10m 3 /day Total potable use per day = 13,5m 3 /day 6

7 Total brine disposed to sewer per day = 7,5m 3 /day Treatment steps in the RO plant are: 1. Sand filter with micron filtration, 2. Carbon filter for groundwater pollution protection, 3. A softener, which reduces calcium & magnesium build up to protect the RO membranes, 4. Birm filter to remove the soluble iron, 5. A thin film composite membrane (TFCM) at micron to remove excessive salt & bacteria, 6. Ozone generators which assists with sterilization & iron oxidation, 7. And lastly UV sterilization for bacteriological safety. Position of borehole Figure 5: Position of borehole indicated by red arrow and light blue circle Total annual abstraction is approximately m 3, with the highest irrigation needs during the drier months (November to April). Various water saving initiatives have been designed into the irrigation system on site: All irrigation nozzels are waste water/hard water compliant and the entire irrigation system is run via a hunter decoder controller; The landscaping on site makes use of endemic and indigenous plants in the design, and a rain meter is used to reduce abstraction and irrigation during rainfall periods via a Hunter weather station, which measures dampness levels in soil, wind direction and speed, as well as switching off the irrigation system when it rains. The landscaping design complies with the minimum requirements by City of Cape Town in order to minimise the overall need for irrigation. The irrigation system is on a timer to keep to the minimum irrigation needs and times, with seasonal adjustments and after grow in period 7

8 adjustments, and the design minimises losses through the use of Hunters matched precipitation Nozzels, which means an always perfect precipitation rate even throughout the different nozzle sizes. Irrigation is also split between trees and shrubs/groundcovers, which allows the isolation of trees only if the shrubs/groundcover do not need irrigation and vice versa. Water saving initiatives inside the centre is driven by the current need to save on potable use within the City of Cape Town area. Initiatives not only include management aspects such as dry sweeping and minimising washing down of areas unless required by sanitation standards, but also installation aspects such as water saving taps and toilets. Shoprite Checkers (Pty) Ltd is dedicated to global best practice and continuous improvement and will incorporate new initiatives as they become available over time. With the current drought conditions in the Western Cape, and in particular the need for alternative sources within the City of Cape Town area, the site needs to minimise its reliance on municipal water. 8

9 5. Section 27 Motivation for WULA 27. (1) In issuing a general authorisation or licence a responsible authority must take into account all relevant factors, including - (a) existing lawful water uses; An existing lawful water use (ELWU) is a water use that lawfully took place in the period two years before the commencement of the National Water Act (Act 36 of 1998). This allows any water use that lawfully took place to continue until such time as it can be converted into a Licence. No existing lawful uses exists for this site. A General Authorisation (Ref: 27/2/1/G1122/474/1) was registered for this property in October 2017, and this WULA will replace the GA once authorised. (b) the need to redress the results of past racial and gender discrimination; The Shoprite Group sees itself as a responsible corporate citizen contributing on an ongoing basis to the wellbeing of the communities wherein it does business. The Group has always been proud to initiate and support projects aimed at community development and benefiting the lives of others. Its social-investment programmes focus on a number of areas, but particularly on Women Empowerment, Skills Development and Hunger Relief, sharing wealth and resources with a broader set of stakeholders and investing in community and society improvement projects that have proven to be sustainable, and continue to deliver ongoing benefits where there is a need. (c) efficient and beneficial use of water in the public interest; The proposed water use linked to the site will make use of underground water. It will relieve the pressure on the potable water supply by City of Cape Town (CoCT) locally, and according to the yield test (see Appendix A) the aquifer can sustain the use on site. Various efficiency measures have been put in place for the landscaping irrigation on site in order to minimise the need of abstraction from the borehole. These include: use of endemic/ indigenous plants in landscaping design; use of weather station to reduce abstraction and irrigation during rainfall periods; planned irrigation during low evaporation times; landscaping design to comply with minimum requirements by CoCT in order to minimise need for irrigation; irrigation system on timer to keep to mimimum irrigation needs and times, including seasonal adjustments and after grow in period adjustments, irrigation system design minimises losses through use of Hunters matched precipitation nozzels, which means an always perfect precipitation rate even throughout the different nozzle sizes, irrigation is also split between trees and shrubs/groundcovers which allows trees to be isolated if shrubs/groundcover do not need irrigation or vice versa, 9

10 each irrigation solenoid is also pressure regulated to always operate at 100% efficiency zero loss/overage. With the current drought conditions in the Western Cape, and in particular the need for alternative sources within the City of Cape Town area, the site needs to minimise its need of municipal water. (d) the socio-economic impact - (i) of the water use or uses if authorised; or The proposed water use linked to the development will make use of underground water. This relieves the pressure on the potable water supply in the area by CoCT (City of Cape Town), and will also decrease the risk of losing the initial capital investment in the landscaping during future times of drought. The new development will be a mixed use development, with a shopping centre site with Shoprite as the anchor tenant. It will employ people from the local community and CoCT as a whole, and therefore have a knock-on effect on the local economy and job creation market. If the site can sustainably provide its own water it will minimise the risk of job losses during periods when there is minimal/ no municipal supply available. (ii) of the failure to authorise the water use or uses; If the proposed water use is not authorised the site will then need to use potable municipal water for the irrigation and potable needs on site over the amount allowed by the GA, which will place added pressure on already scarce potable water resources in the Cape Town Metro area. (e) any catchment management strategy applicable to the relevant water resource; None at this time. (f) the likely effect of the water use to be authorised on the water resource and on other water users; According to the borehole siting report in Appendix A, there are no registered boreholes within the 1km search radius of the site. (g) the class and the resource quality objectives of the water resource; The site lies within quaternary catchment G22K within the Berg-Olifants Water Management Area (see Figure 3). According to the geohydrological report (Appendix A) the site is underlain by quartzose greywacke and mudrock of the Tygerberg Formation (Malmesbury Group). The aquifer underneath the site is classified as fractured with an average borehole yield potential of litres per second. The verified yield of the borehole is within range at 0.97 litres per second (see Appendix A). (h) investments already made and to be made by the water user in respect of the water use in question; Shoprite Holdings has invested extensively in the purchasing of the land, the building of the infrastructure, the landscaping and environmental management compliance requirements in the Environmental 10

11 Authorisation, which shows commitment and long term investment in the area. Extensive capital investment has also been made in the installation and design of the water efficient irrigation system, the borehole and the treatment plant to enable potable use on site. (i) the strategic importance of the water use to be authorised; The authorisation of the proposed water use will be strategic from an economic point of view: 1) enabling the use of available groundwater and, 2) relieving the pressure on available potable City of Cape Town sources, and by implication enabling the municipality to distribute potable water to more users in the long term, 3) creation of localised economic activity and employment opportunities within the community. (j) the quality of water in the water resource which may be required for the Reserve and for meeting international obligations; and There is at present no reserve determined for the underlying aquifer. There are no international obligations to be met as far as water distribution is concerned. (k) the probable duration of any undertaking for which a water use is to be authorised. The Water use authorisation is linked to a long term investment and operational presence of Shoprite Checkers (Pty) Ltd in the area, and should be reviewed every 5 years to ensure demand and use appropriateness. 11

12 6. Public consultation on WULA As per Regulation 267 published on 24 March 2017 (Government Gazette 40713) public participation must be conducted as part of the water use licence application process. During the meeting with DWS on 24 October 2017 regarding the WULA requirements, the applicant was requested to place an advert according to S17(3)(d) of R267, place site notice boards according to S17(3)(a) and at the local library with the technical report for comment, and notify adjacent landowners of the WULA process. Public participation will be conducted for a period of 60 days from 11 January up to and inclusive of 12 March 2018, after which all comments received from any I&AP will be recorded in a register for consideration by the responsible authority, along with the final report. 12