Visual Specialist Opinion on Preferred Layout Alternative 4 September 2014 (Megan Anderson of MALA)

Transcription

1 Visual Specialist Opinion on Preferred Layout Alternative 4 September 2014 (Megan Anderson of MALA)

2 Sillito Environmental Consulting Suite 105, Block B2 Tokai Village Centre Vans Road Tokai September 2014 Attention: Colleen McCreadie Dear Colleen ERF 2224, HOUT BAY VISUAL SPECIALIST REVIEW OF AMMENDED LAYOUT ALTERNATIVE 4 Further to our correspondence, herewith our findings with regard the Proposed Layout Alternative 4 for Erf 2224, Hout Bay. We have reviewed the letter from J Paul Van Wyk, Urban Economists and Planners cc, addressed to yourselves, dated 08 April 2014, with regards the Townplanning Considerations: Response to matters raised by DEA&DP., This has provided a clear understanding of the amendments to the SDP and tabled Layout Alternative 4. The amendments include: a re-configuration of erven in the southern enclave such that buildable areas and access roads would not be on slopes greater than 1:4, with specific prescriptions in the EMP; access considerations; increase ecological buffer along the Bokkemanskloof River as well as no encroachment of residential erven into this area, however a marginal encroachment to provide access to proposed Erf 30; a reduction in the number of single residential erven from 73 to 65; a reduction of the number of units (from 23 9) between the CPPNE-line and CCMM Urban Edge line which equates to fewer units on the higher lying slopes; and of these 7 higher lying erven, building platforms are situated lower down the slope as a result of steeper slopes; and firebreaks and firetruck tracks are incorporated. These amendments provide for further mitigation of visual impacts as follows:

3 1. Change from un-built, open area to a built landscape the Layout 4 Preferred SDP has fewer single residential erven equating to less built area. Furthermore, the more visible and visually sensitive upper reaches of the site will be left open and un-built. 2. Visibility from scenic tourist route the fewer single residential areas on the upper slopes, which are more visible from the scenic routes, reduces this visual impact. 3. Light Pollution should be marginally reduced as there are less single residential erven. We confirm that part visual requirements of the previous report have been met however the required mitigation measures must still be met: Extensive tree planting along roads to reduce visibility of buildings and provide a green mountain view; appropriate landscaping in POS; architectural guidelines; and lighting guidelines and control. In addition, it would be necessary to have landscaping guidelines/controls provided for the residential erven that the CPPNE and CCMM Urban Edge lines, so that in-appropriate landscape development is prevented. I trust you find the above sufficient. If you have any queries, please do not hesitate to contact me. Yours sincerely Megan Anderson (PrLArch)

4 Civil Engineering Services Report, August 2014 (Eckon Engineers)

5 CONSOLIDATION OF PORTION OF ERF 8343 & ERF R/2224, HOUT BAY AND SUBDIVISION OF CONSOLIDATED ERF. CIVIL ENGINEERING SERVICES REPORT 1. INTRODUCTION Ekcon (Pty) Ltd was appointed to investigate the effect of the proposed consolidation of portion of erf 8343 and erf R/2224, Hout Bay and subdivision of consolidated erf on the Civil Engineering services infrastructure. Erf R/2224 was rezoned to Sub divisional Area on 13 July 1994 for a maximum of 88 single residential erven, 2 rural erven and 1 special residential erf (to comprise of a maximum of 8 units). 2. SITE LOCATION AND DESCRIPTION The site is situated in the Upper Valley area in the north-eastern parts of Hout Bay on the western slopes of the Constantiaberg stretching southward between the Vlakkenberg (east) and Skoorsteenkop (west) mountain peaks, south of Hout Bay Main Road. The Bokkemanskloof River runs from south to north through the property. Oakhurst Estate and erf 8343 are located north west of the proposed development. The property falls under the jurisdiction of the South Peninsula Administration of the City of Cape Town. 3. EXISTING SERVICES 3.1 Roads Blue Valley Avenue is located parallel to the eastern boundary of the site. Several side streets (Gumtree, Pine, Conifer, Birch, Asch, Restio, Myrica, Saffron) are located along the west of Blue Valley Avenue and terminate on the eastern boundary of erf 2224.

6 2 A services servitude traverses the site south of the proposed High Level Road for the Municipal water supply. Currently a gravel road exists within this servitude and crosses the Bokkemanskloof River by means of stormwater culverts under. 3.2 Stormwater The site falls naturally at an average slope of approximately 12% in a northerly direction and towards the Bokkemanskloof River. The Bokkemanskloof river is the natural drainage route for the greater catchment area of 196 hectares (refer to Figure 5) and drains through three existing culverts under the pipetrack. A battery of four mm diameter culverts are located in the main Bokkemanskloof Stream and has a capacity of approximately 24m³/s. Two mm diameter culverts are located 40m to the west of the main channel and have a combined capacity of approximately 12 m³/s. Another set of four 600 mm diameter culverts are located to the east of the main channel and has a capacity of approximately 4 m³/s. The combined culverts are capable of passing the 1:100 year peak flow of 34 m³/s without the pipe track overtopping. However, there is a high risk that the drop inlets to the main culverts will become blocked by debris. Consequently, the floodlines have been derived on the assumption that this will occur and that the pipe track will be overtopped. The Bokkemanskloof Stream and its tributaries has a total catchment area of 1,96 km² where it crosses the pipe track at the bottom of the erf. The catchment can be divided into three subcatchments corresponding to the catchments of the watercourses that cross the erf, namely: Catchment 1: the main Bokkemanskloof Stream catchment 1,21 km² in area Catchment 2: the catchment of the minor stream that discharges on the east side of the main channel to the culvert under the track, with an area of 0,26 km² Catchment 3: the catchment of the tributary stream to the west of the main watercourse with an area of 0,49 km². The catchments comprise steep mountain slopes. The Mean Annual Precipitation for these catchments is 958mm. An existing open stormwater channel runs along the eastern boundary of the property as an overland escape route for the stormwater from the Blue Valley Development. P:\Ekcon\Projects Ekcon\1866 ERF 2224 Oakhurst\Admin\Reports\REVISED CIVIL ENG SERVICES REPORT doc

7 3 3.3 Sewerage An existing 150 mm diameter sewer pipe is located 1,5m inside the eastern boundary of the site for almost the entire length of the boundary. A sewer line was installed for the new Farm Stall development on erf 8292 and was extended across Dorman Way as a connection for erf Other sewer lines are located in the private development north-west of the proposed subdivision. Sewer lines will also be provided with the proposed development of erf 8343 west of the Bokkemanskloof River. 3.4 Water An existing water main is located along Blue Valley Avenue to the east of the proposed subdivision. Pipes are also located along the side streets from Blue Valley Avenue up to the eastern boundary of property. Water pipes are also located along Dorman Way. Water services are located in the private development north-west of the proposed subdivision. New water services will also be provided with the proposed development of erf 8343 west of the Bokkemanskloof River. As noted under 3.1 above, a services servitude is registered south of the proposed High Level Road for the municipal bulk water supply pipe line. 4. NEW SERVICES All new services will be designed according to the Guidelines for the Provision of Engineering Services for Residential Townships (Blue Book) and Municipal requirements. 4.1 Roads (Refer to drawing P1866-C-002) A portion of the property will be allocated as road reserve for the proposed new High Level Road. This bypass road has been designed by Jeffares & Green and the proposed layout is indicated on drawing P1866-C-002. The construction of this road will cut off the access to the southern portion of Blue Valley Avenue. To overcome this problem Jeffares & Green have P:\Ekcon\Projects Ekcon\1866 ERF 2224 Oakhurst\Admin\Reports\REVISED CIVIL ENG SERVICES REPORT doc

8 4 indicated an access road from the proposed High Level Road across the existing pipe track onto Blue Valley Avenue. From discussions with Jeffares & Green it became evident that the exact position of the proposed access is flexible and it could move west or east. Access to the north-eastern parts of the property can be provided from the side streets off Blue Valley Road. Access to the portion of property south of the proposed High Level Road will come from Blue Valley Avenue via the pipeline servitude. This route was recommended and approved with the original re-zoning application. Discussions were held with Municipal Officials at Kendal Water Works who confirmed that they did not have any in-principle objections to this proposal. All internal roads can be classed as residential Access loops (Class 5b) or Access culs-desac (Class 5c) and will be located in 10m wide road reserves. A surfacing width of 5,5m is proposed with a cross fall and precast mountable kerbs on both sides. A typical road crosssection can be found on drawing Figure 1. The proposed kerb radii at intersections are 6,0m. The town planning layout was designed such as to avoid steep road gradients; however in some instances this could not be avoided. One can expect that the preferred maximum gradient of 12% (1:8) will be exceeded for some sections of the internal roads. It is recommended that the maximum gradient must not exceed 15% (1:7). 4.2 Stormwater management (Refer to Stormwater management plan MC145-C900 and Stormwater management report MC145/1) The steep topography of the terrain results in a high run-off factor. There will only be a small increase in run-off due to the development. The run-off from the roads and erven will be managed with the use of permeable lined open drains, permeable paving along roads and the use of public open spaces as filtration areas for the storm water runoff generated over the development. All storm water will eventually be discharged into the Bokkemanskloof River which is the natural overland escape route for the major storm event. Please refer to Stormwater Management plan MC145-C900 and Stormwater Management report MC145/1 prepared by Graeme McGill Consulting for a detailed description of the storm water management plan for the proposed development. P:\Ekcon\Projects Ekcon\1866 ERF 2224 Oakhurst\Admin\Reports\REVISED CIVIL ENG SERVICES REPORT doc

9 5 4.3 Sewer reticulation (Refer to P1866-C-003) The expected peak sewer flow from the proposed development is 3.4 l/s. The proposed development will be provided with 150mm diameter gravity underground water borne sewerage system making provision for 110mm diameter erf connections. Sewer for the south-eastern portion of the property will be collected in pipes along roads, servitudes and through the private open spaces to two foul sewer manholes situated on the lowest points located on the outside of the most northern and most western corners of erf 47. The sewerage for the south-western portion of the property will be collected in pipes along roads, servitudes and through the private open spaces to a foul sewer manhole located directly north of erf 55. This manhole then links with the foul sewer manhole situated on the outside of the most western corner of erf 47. As an alternative proposal the sewerage from the south-western portion of the property can also be collected on the north-western side of erf 52 piped through private open space forming part of Oakwood Estate and ultimately draining towards an existing foul sewer main running parallel to the proposed new bypass road. This option however will only become viable once the approval of Oakwood HOA has been obtained. The sewerage collected in the two manholes situated on the outside of erf 47 will be conveyed towards the existing foul sewer main situated on the outside of the most northern corner of the property by means of linking it to the new foul sewer main to be provided for the erven on the northern portion of the property. The sewer collected from the northern portion of the property in pipes along roads, servitudes and through the private open spaces together with the sewer from the south-western and south-eastern portion of the property will thus be drained towards the existing foul sewer main situated on the outside of the most northern corner of erf 29 except for erf 16 to 19 which will drain towards an existing foul sewer manhole situated north-west of erf P:\Ekcon\Projects Ekcon\1866 ERF 2224 Oakhurst\Admin\Reports\REVISED CIVIL ENG SERVICES REPORT doc

10 6 4.4 Water reticulation (Refer to drawing P1866-C-004) The average erf size is 1 200m². The average water demand per erf is estimated at 2200l/day. The domestic peak flow is 13.7l/s (PF of 8). A minimum flow for fire hydrants of 6l/s is recommended. The proposed development will be provided with 110mm diameter supply water mains. Individual 22mm diameter connections will be provided for each erf. Municipal meters will be installed to individual erven. The proposed development can be classed a Low-risk-Group1 fire risk and therefore requires fire hydrants at 240m spacing. 4.5 Refuse removal Refuse removal facilities will be provided and arrangements made for collection in accordance to the Integrated Waste Management Policy of the City of Cape Town and the guidelines for minimum requirements for waste collections and waste storage areas/rooms published by the solid waste management department. 5. CONCLUSION From the above we confirm that all the Civil Engineering services can be provided for the proposed consolidation of portion of erf 8343 and erf R/2224, Hout Bay and subdivision of the consolidated erf. MW CASPER Pr Tech Eng for EKCON 26 Aug 2014 P:\Ekcon\Projects Ekcon\1866 ERF 2224 Oakhurst\Admin\Reports\REVISED CIVIL ENG SERVICES REPORT doc

11 NOTES: 1. THIS DRAWING IS BASED ON THE WGS84 2. THE CONTRACTOR SHALL OBTAIN ALL THE NECESSARY WAY LEAVES AND PERMITS BEFORE STARTING WITH ANY WORK ON SITE 3. HEIGHTS ARE BASED ON m ABOVE MSL. 4. ALL SERVICES: WATER, SEWER,STORMWATER,TELKOM, AND ELECTRICITY TO BE PROPERLY BLANKED OFF AND MADE SAFE BEFORE COMMENCING WITH ANY WORK ON SITE. 5. SERVICES: THE POSITION OF U/GROUND SERVICES MUST BE VERIFIED ON SITE BEFORE CONSTRUCTION. 6. ALL WORK TO BE IN ACCORDANCE WITH THE RELEVANT SECTION OF THE SABS A NR. NO. DATUM DATE SYSTEM. FOR COMMENT WYSIGING REVISION GETEKEN DRAWN TEL:(021) FAX:(021) KLIENT CLIENT PROJEK PROJECT ERF 2224 HOUTBAY TEKENINGTITEL Large boulders Large boulders DRAWING TITLE WATER LAYOUT NAAM NAME ONTWERP DESIGNED GETEKEN DRAWN NAGESIEN CHECKED SKAAL SCALE 1:500 DATUM DATE GOEDGEKEUR APPROVED 2014 PR ENG TEK/DWG STATUS P1866-C-004 WYSIGING REVISION A P

12 CENTRELINE OF ROAD ROAD RESERVE BOUNDARY NOTES: 1. THIS DRAWING IS BASED ON THE WGS84 SYSTEM. 2. THE CONTRACTOR SHALL OBTAIN ALL THE NECESSARY WAY LEAVES AND PERMITS BEFORE STARTING WITH ANY WORK ON SITE 3. HEIGHTS ARE BASED ON m ABOVE MSL. 4. ALL SERVICES: WATER, SEWER,STORMWATER,TELKOM, AND ELECTRICITY TO BE PROPERLY BLANKED OFF AND MADE SAFE BEFORE COMMENCING WITH ANY WORK ON SITE. 5. SERVICES: THE POSITION OF U/GROUND SERVICES MUST BE VERIFIED ON SITE BEFORE CONSTRUCTION. 6. ALL WORK TO BE IN ACCORDANCE WITH THE RELEVANT SECTION OF THE SABS SURFACING BASECOURSE SUBGRADE ELECTRICAL NGL MK10 KERB 2.5% CK5 KERB TELKOM WATER SEWER STORMWATER A NR. NO. DATUM DATE FOR COMMENT WYSIGING REVISION GETEKEN DRAWN TEL:(021) FAX:(021) KLIENT CLIENT PROJEK PROJECT ERF 2224 HOUTBAY TEKENINGTITEL DRAWING TITLE ROADS LAYOUT Large boulders Large boulders NAAM NAME ONTWERP DESIGNED GETEKEN DRAWN NAGESIEN CHECKED SKAAL SCALE 1:500 DATUM DATE GOEDGEKEUR APPROVED 2014 PR ENG TEK/DWG STATUS P1866-C-002 WYSIGING REVISION A P

13 NOTES: 1. THIS DRAWING IS BASED ON THE WGS84 2. THE CONTRACTOR SHALL OBTAIN ALL THE NECESSARY WAY LEAVES AND PERMITS BEFORE STARTING WITH ANY WORK ON SITE 3. HEIGHTS ARE BASED ON m ABOVE MSL. 4. ALL SERVICES: WATER, SEWER,STORMWATER,TELKOM, AND ELECTRICITY TO BE PROPERLY BLANKED OFF AND MADE SAFE BEFORE COMMENCING WITH ANY WORK ON SITE. 5. SERVICES: THE POSITION OF U/GROUND SERVICES MUST BE VERIFIED ON SITE BEFORE CONSTRUCTION. 6. ALL WORK TO BE IN ACCORDANCE WITH THE RELEVANT SECTION OF THE SABS A NR. NO. DATUM DATE SYSTEM. FOR COMMENT WYSIGING REVISION GETEKEN DRAWN TEL:(021) FAX:(021) KLIENT CLIENT PROJEK PROJECT ERF 2224 HOUTBAY TEKENINGTITEL DRAWING TITLE SEWER LAYOUT Large boulders Large boulders NAAM NAME ONTWERP DESIGNED GETEKEN DRAWN NAGESIEN CHECKED SKAAL SCALE 1:500 DATUM DATE GOEDGEKEUR APPROVED 2014 PR ENG TEK/DWG STATUS P1866-C-003 WYSIGING REVISION A P