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EXECUTIVE SUMMARY Water Supply A combination of sources will be used to supply the bulk water requirements of the development. If liscences can be obtained bulk raw water from the Kei River will be pumped into storage dams built specifically to supply water for the Morgan's Bay and Kei Mouth requirements. A treatment plant and storage reseNoir will be built to handle the development's needs. A new distribution infrastructure, including pipelines, booster pump stations and pressure reducing valves will be installed to enable the supply of water to the proposed development to be to the design standard requirements. Sewage Disposal Either a conventional septic tank, a hybrid toilet system , or the ' GEM ' multi tank system will be used. The percolation results from the geo-technical investigation were not specific enough to enable us to be definitive on which system will be the best to use. Further testing which will be conducted when detailed development designs are produced and we envisage certain clusters will be able to handle conventional septic tanks. Electrical Supply One connection will be made to the existing Eskom line that supplies fanm portion 77 in order to provide the total load of 1.75 MVA for the development. An underground cable network will provide electrical power to the eNen, hotel and pump stations. Eskom have given an assurance that supply is not an issue. Roads r New internal road infrastructure will be built to provide movement in and around the development, with the existing access from the R 349 being upgraded to suit specifications if necessary. Storm water New storm water infrastructure will be installed as and where required to provide proper drainage for the development. Figure 1: Concept plan of development P1 001 - Eng Servi ces Report rev1.doc 5 Kei River Eco Development _I c ~ E C- 0 Q; ~ ~i 0 w8 ~ !!I..uI,1 IIQ ~ ~ z o t= u :l Q o 0:: I­ ~ ..: 0; a:o ~- , Mango Grove Eco Estate is an initiative from local private developers that have identified the need for a lUxury eco residential and tourism development in the Kei River area. The private developer is known as the Wood/Change Gear JV cc, and they will fund and manage the implementation of this Development. This Engineering Services Report will review all the engineering services currently in place and, based on the estimated demands of this Development, will make proposals on the upgrading requirements. The following services will be addressed : • Water services; • Sanitation facilities; infra structural requirements, discharge methods, etc. ; • Electricity supply; bulk and intemal reticulation, etc. • Storm water; the control of runoff, flood line determination, etc.; • Road and Traffic aspects; access infrastnucture, layer works, pavement design and alignment, etc. David Offerman Consulting Engineers were appointed to manage the above actions and will be responsible for the planning, detailed design and Engineer's drawings, compilation of tender documentation, bill of quantities and project specifICations. They will also be responsible for the calling for construction quotations, the supervision of the construction progress, quality, certify payments for construction, and all other aspects of the project management involved in this development. 2, SPECIFICS 2.1 Description The Mango Grove Eco friendly development is to be situated approximately 9 km from the town of Kei Mouth, which is in the Great Kei Local Municipality. The local municipality falls within the Amathole District Municipality of the Eastern Cape Province. The development is also only 70 km from East London, a major city in the region. A reduced 1: 20 000 topographical map ( see Figure 2 above ) outlines the farm portions making up the development. The proposed development will be based on an eco estate format consisting of approximately 115 high income residential stands and a hotel complex comprising approximately 35 rooms. This development will focus on the upper income market. As can be seen from the map the development will be situated on Portions 72, 73, 74, 75/1 , 76, 77,78 and 79 of the farm Rocky Ridge. The area is approximately 1150 hectare and is bordered by the Kei River on the northern and eastern boundaries. All other boundaries of this Development are privately owned lands. 2.2 Topographical Features The geology of the area is made up of mudstones and sandstones of the Karoo sequence. In many cases these have been intruded by dolerite dykes and sheets. One such dyke nuns across the property in a south east to north east direction and is perpendicular to the iCwili River. Dolerite dykes are well known bore hole sites. ( for underground water) With the dyke cutting off the stream it should have excellent recharge potential. The topography of this development is varied with large flat plateaus that slope gently to the south east. These flatter slopes give way to gently undulating ones around the drainage lines, and steep to very steep slopes in the iCwili River gorge and the Kei River gorge. If we put some numbers to these slopes the site rises from approximately 40 mas I in the south east to around 204 masl in the north west. The Beaufort Group is the geologically dominant group in the district and forms part of the Karoo Supergroup. The Beaufort Group is divided into two subgroups, namely the Tarkastad and the Adelaide, which in turn can be themselves divided into formations. The following formations, the Katberg formation and the Balfour formation, make up the geology of this development. The Katberg formation is sandstone rich and is 500 to 1000 mm thick. The sandstone is well lithified and varies in composition from a fine grained, argillaceous variety to a medium coarse grained, arenaceous type. The sandstone is horizontally laminated, cross bedded or massive, and on average comprises 90% of the total thickness. The geology is responsible for the soil types and together they influence the runoff coefficient for the dams. There are three predominant soils, namely P1001 - Eng Services Report rev1 .doc 7 Kei River Eco Development , I • Shallow sandy soils that occur on sandstone. They have a bleached layer above the partially weathered • underlying rock and are extremely erodible. • Deep alluvium associated with the small non perennial streams that flow into the great Kei River • Deeper red to brown soils associated with the dolerite sheets. They have a high clay content. One of the important properties we can glean from a study of the soils is the way that they take up rain water. By knowing this we can determine the amount of runoff that will take place. 2.3 Climate The average annual rainfall is 1056 mm with a medium of 840 mm. Two distinct peaks occur in spring and autumn although none of the months are exceptionally dry. Thunder storms of high intensity are frequent and can cause erosion. If the soil horizon is saturated flooding can occur. The following is evident from the rainfall figures, namely: • March has a high average of 105 mm • July and August can be exceptional ( 155 mm and 447 mm respectively) • From the properties of the existing soils found on the properties preliminary rainfall is required to saturate the unconsolidated soil profile before runoff can be expected and thus we can expect runoff to peak in the March and October months. The shallow soil profiles in certain areas could increase runoff to 22% ( regional runoff coefficient is 15% ) 2.4 Water Demand For this development the design is based on the Red book, with a Fire Risk category of Low-risk group 1. The 115 new residential properties will be classified as high income, and hence the estimated water demand was based on the following calculations : • each erf area = 1200 m' average; • MOD = 1200 IId/erf = 138 m3/day for individual erven (Annual Average Daily Demand) • MOD =4 IId/m2 =4 m3/day for the hotel • Conveyancing losses =10 % and Summer Daily Demand (SDDPF) peak factor =1 .5; • Design peak demand = 234.3 m3/d ( = 2,7 lis ) exclusive of fire demand; • Fire Demand = Low Risk - group 1 = 900 IImin, for 2 hour duration. The main constraints are: Annual Averaqe Daily Demand ( AADD ) Erven 138 m3/day 115 x 1200Vd ~otel 4 m3/day ~ x1000Vd irotal 142 m3/day Annual Demand 1830 m3/annum Water Conveyancing Losses ( L ) 0 y, Summer Daily Demand Peak Factor ( SDDPF) .5 Design Flow for the bulk main and pumps to the storage reservoir ( DFR ) 12.7 Is \ADD x L x SDDPF Reservoir Size 77 m3 x DFR + 2 h Fire Flow P1001 - Eng Services Report rev1 .doc 8 Kei River Eco Development Peak Factor ( PF) .5 Desion Flow 12.3 Is IPFxAADD Maximum Pressure 90 m Static Head Minimum Pressure 4 m under PD Maximum Velocitv in PiDes 1.2 mls Fire Flow ( Low-risk GrouD 1 ) 900 Imin nder PD with one hydrant Minimum Fire Pressure ~ m ooen I Maximum Distance from a hydrant 40 m Maximum Fire Flow Velo"lty in PiDes mls 2.5 Sewage Disposal In most large cities and towns water borne sewage systems are in place which either gravitate the sewage to a central pump station, from which the sewage will be pumped, or else the sewage flows directly to the sewage treatment plant. However, in the rural areas and in smaller towns this is not always possible and on site ( i.e. at each property) sewage treatment processes are considered as completely acceptable viable alternatives. Numerous studies have been done on sewage treatment systems and all have specific advantages and disadvantages. Various systems are available on the market and infrastructural, as well as maintenance, costs are relatively economical. If the environmental constraints are not affected then the recommended alternative will mainly depend on the preference of the Developer based on the type of development and the economical aspects.

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