Tamarina Beach Club Hotel Extension
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5 BASELINE ENVIRONMENT Drawings relevant to this section are as follows: Topographic Plan including Tree Survey Location Plan 5.1 DESCRIPTION OF PROJECT SITE AND PROJECT AREA 5.1.1 Project Site The site is freehold land located at Tamarin on the Western coast of Mauritius in the District of Black River. As per the Black River Outline Scheme, the site is located within settlement boundary and the South West Tourism Zone that extends from Flic en Flac/Wolmar to Le Morne Peninsula. The Project site is generally bounded as follows: towards the east by the existing Tamarina Beach Club Hotel towards the south by the line of High Water Mark towards the west and the north by Domaine de Wolmar The coastal frontage, approximately 80 m long, is found, between the following coordinates: Latitude 20°19’17.20”S and longitude 57°22’41.66”E north site Latitude 20°19’14.95”S and longitude 57°20’40.18”E south of site The site extent is of 36,938.84m2 excised from all that remains of 900A (Domaine Wolmar) belonging to Medine Ltd as per title deed T.V 555 No 31, 3nt (Refer to Appendix A for Land Survey plan and Title Deed). Medine Ltd has confirmed in writing that it has duly authorised its subsidiary, Tamarina Beach Club Hotel Ltd, to proceed with the construction of an extension to its existing 50-room hotel on the aforesaid plot of land (Refer to Appendix A for letter of authorisation). The portion under development for the hotel extension is limited to the coastal frontage and of approximate rectangular shape 65m coastal frontage x 50m inland. Figure 5-1 below show the existing hotel blending in the vegetation and to its left the site earmarked for the proposed hotel extension with a rocky shore. Extension of Tamarina Beach Club Hotel at Tamarin 5-1 September 2014 Existing Hotel Hotel extension Figure 5-1: Aerial view of Existing Hotel and site for Extension to the left The site is currently undeveloped and with alien vegetation cover (refer section 5.3 Terrestrial Biodiversity) There is no natural surface water feature on site (refer section 5.2.3 Site Hydrogeology and Hydrology) There is currently no building on site; no services and infrastructure serving the site. There is however an overhead CEB line that shall be relocated along the site boundary, with CEB approval. Pictures of site are shown in Appendix E and forms part of the EIA report. 5.1.2 The Project Area There is no agreed figures on the extent of a Project Area. It is however commonly considered in Environmental Impact Assessment studies as being land comprised within 1,000 m radius from site; the “Project area” is shown on the Location Plan attached. The Area of Environmental Influence for such type of development, i.e. low density hotel development with associated infrastructure and services, is however much smaller than the project area and can be reduced to 500 m from site boundary; the “Area of Environmental Influence” is shown on the Location Plan attached. The Area of Environmental Influence includes the following main man-made features: To the east, Tamarina Beach Club Hotel and further east (and north east) Tamarina Golf Estate To the west and north, Domaine de Wolmar, being former grazing grounds The Area of Environmental Influence includes the following main natural features: To the south west, the line of high water mark. It should be noted that there is no reef opposite the site, thus no lagoon. Extension of Tamarina Beach Club Hotel at Tamarin 5-2 September 2014 5.1.3 Site Topography As shown on the topographic plan attached, the site slopes in a general north-east to south-west direction and towards the sea. The blocks located at the rear of the portion of land to be developed for the hotel extension are generally found on contour 6.5m; the blocks located at the front are generally found on contour 4.5m; both are distant of about 35m. The slope is thus generally in the range of 5-6%. 5.2 GEO-DATA 5.2.1 Site Geology The geology of Mauritius is dominated mostly by deposits of basaltic lavas following volcanic activities which occurred during two distinct periods. The general series of basaltic rocks are as described in the Table 5-1 below. LAVA SERIES AGE (MILLION YEARS BC.) Younger Volcanic Series Late Lavas 0.025 to 0.2 Intermediate Lavas 0.5 to 0.7 Early Lavas 1.7 to 3.5 Older Volcanic Series 6.8 to 7.8 Table 5-1: Volcanic Series From the “Land Resource and Suitability Map, FAO/MSIRI”, extract of which is reproduced in figure 5-2 below, the project area lies within the northern and western intermediate lava plains and slopes (index 2.4). 2.4 site Figure 5-2: Geological Map - Land Resource and Suitability Map According to the 1:50,000 Geological Map of Mauritius, the site is underlain by fresh basalt of the Younger Volcanic Series that are characterised by uniform doleritic facies. These lavas are light greyish in colour and show many phenocrysts (large crystal surrounded by a finer-grained matrix in an igneous rock) of olivine scattered in the doleritic network of feldspars and pyroxenes (silicate Extension of Tamarina Beach Club Hotel at Tamarin 5-3 September 2014 minerals). They are often porous and vesicular and show many cracks and fissures, but they are also sometimes compact. Scoriaceous textures are common, mainly at the upper and lower parts of the flows. Weathering is in general not important and is very often in concentric beds production onion-type alteration structures. According to the Soil Map of Mauritius, the natural strata consists of Grey Hydromorphic Soils. These soils have developed below the 1,250mm isohyet. The typical profile consists of a greyish cast A horizon over a B horizon showing grey, yellow or brown mottlings. 5.2.2 Site Geotechnical Conditions The following description is extracted from the Geotechnical Report issued by Water Research Co Ltd (refer Appendix F) The depth and thickness of the various strata observed in the Trial Pits are shown in the logs and are summarised in Table 5-2. Trial Excavation Elevation Groundwater STRATA (m) Pit Depth (m) Depth Topsoil Completely Moderately (m) (m) weathered Basalt weathered basalt TP1 2.75 6.50 2.5 0.00-0.030 0.30-2.75 -- TP2 2.75 4.25 2.75 0.00-0.035 0.35-1.70 1.70-2.75 TP3 1.95 3.50 -- 0.00-0.030 -- 0.30-1.95 Table 5-2: Summary of Geotechnical Data The following sections summarise the descriptions for each of the encountered strata. 1. Topsoil. Topsoil was encountered for all Trial Pits from the surface in an average thickness of 0.30m and was generally described as soft dark brown to black very gravelly low plasticity sandy Silt with frequent roots and sub rounded cobbles and boulders. 2. Weathered Basalt – Clay. Completely Weathered Basalt (CWB) was encountered at TPs 1 and 2 underlying the Topsoil. The stratum was generally described as firm light greenish brown with white deposits very gravelly high plasticity silty Clay with frequent sub rounded cobbles and boulders 3. Weathered Basalt – Rock. Moderately Weathered Basalt (MWB) was encountered at TPs 2 and 3 underlying the Completely Weathered Basalt layer or the topsoil and extending to a minimum depth of 2.75m. Thickness of this stratum ranges between 1.0m to 1.5m. The MWB was described as moderately weak to moderately strong creamish grey with orange and black discolorations vesicular very closely jointed. The thickness of the weathered rock varied between 1.05m to 1.65m and it extended to the maximum explored depth of 2.75m. 4. Groundwater. Groundwater was encountered at trial pits TP 1 and 2 only. Groundwater observations were carried out for 48hrs and not fluctuations in the groundwater level were observed. Extension of Tamarina Beach Club Hotel at Tamarin 5-4 September 2014 5.2.3 Site Hydrogeology and Hydrology (i) Site Hydrogeology The hydrogeology of a site pertains to the underground water features of this site. The site lies within the aquifer of Curepipe/Vacoas/Flic-en-Flac commonly known as the Curepipe aquifer, and more precisely in the coastal reservoir of Flic en Flac – Tamarin. This aquifer comprises: 1. The western part of the intracalderic groundwater reservoir centred on Arnaud-Curepipe point; 2. The median reservoir of Palma – Beaux Songes, limited to the south by Montagne du Rempart/Trois Mamelles and to the north by Montagne St Pierre/Corps de Garde/ridge of Candos; 3. The coastal reservoir of Flic en Flac – Tamarin. It is a multi-layer aquifer constituted by the superposition and the juxtaposition of basaltic flows, healthy or more or less weathered, separated by clayish facies. The superficial part of the underground water reservoir flows generally through a unit of healthy basaltic flow (recent basalts and /or intermediate basalts). It has a hydraulic behaviour characterised by a high piezometric gradient (3.2% at Vacoas). The hydrogeological characteristics of the intermediate series (multi-layered aquifers) are very interesting, and the piling of basaltic flows within these series have provided important yields of the order of 300m3/hour. 6.2.3.2 Site Hydrology The hydrology of a site pertains to the surface water features of this site. There are no natural water courses on site. There is no man made irrigation drain on site. According the 1:25000 Map of Mauritius, extract of which is shown in Figure 5-3 below, there is one man made irrigation drain that flows from an upper reservoir down to the sea.