RFI engineering - 20230504 RFI response

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            a. demonstrate compliance with Section 3.2.2 of Austroads’ Guide to Road Design Part 4A
            by calculating the minimum Safe Intersection Sight Distance and demonstrating an
            unbroken line-of-sight can be achieved, both longitudinally and from a ‘layout’ perspective;
            b. demonstrate compliance with Section 3.2.3 of Austroads’ Guide to Road Design Part 4A
            by demonstrating an unbroken line-of-sight can be achieved, both longitudinally and from
            a ‘layout’ perspective, for the Minimum Gap Sight Distance between both conflict points
            and vehicles travelling along Maple Street; and
            c. assume all parking (cars and buses) are occupied when demonstrating an unbroken line-
            of-sight.

            A traffic assessment has been prepared to validate the adequacy of the sight distances from
            the proposed access with respect to the above points.

            It found that with the removal of the two on-street spaces immediately north of the
            proposed driveway access, the development would be able to achieve the required lines
            of sight to the north. Although a bus in the bus bay would obstruct the sight lines, it is
            considered that the transitory nature of the bus passenger pickup and drop off the bus does
            not represent a permanent obstruction. As drivers will typically have heightened alertness
            due to the requirement to give way to buses, they are more likely to be cautious in passing
            which will ensure safety of the access.

            Assessment of the line of sight to the south found that due to the topography and presence
            of on-street parking, the required lines of sight weren’t able to be achieved without further
            loss of on-street parking. The development therefore proposes a left out only exit which will
            be signed to ensure compliance.

            Issue: Earth Bank Discharge
            3. Provide additional detail demonstrating where and how the runoff from the proposed
            Earth Bank will discharge. The additional detail must be prepared by a suitably qualified
            person (RPEQ – Registered Professional Engineer of Queensland).

            The earth bank proposed for the erosion and sediment controls is a diversion berm which
            will intercept clean run-off from the upstream catchments (the existing dwelling to be
            retained) and divert it around the site works separating the non-polluted water from the
            sediment laden run-off from within the works area. The outlet will discharge at the level of
            the exterior surface through a rock energy dissipating outlet to prevent scour of the verge
            and minimise impacts to pedestrians.

            Issue: Passing Opportunity & Vehicle Manoeuvrability
            4. Provide additional detail demonstrating how the internal driveway between Chainages
            40 and 80 will function to avoid vehicle accidents. The additional detail must be prepared
            by a suitably qualified person (RPEQ – Registered Professional Engineer of Queensland) and
            include, but not be limited to:




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            a. provide Turning Path plans demonstrating that two B99 vehicles can simultaneously
            manoeuvre the internal driveway between Chainages 40 and 80 without colliding; and
            b. demonstrate if vehicles can complete the left-hand turns at Chainages 50 and 70 without
            crossing the centreline of the proposed internal driveway.
            c. if vehicles must cross the centreline of the proposed internal driveway during these left-
            hand turns and/or cannot simultaneously manoeuvre the internal driveway, provide
            comment on what driver has ‘right of way’ to avoid collisions and how this is indicated.

            Please refer to the Traffic Assessment report which addresses this matter. The assessment
            found two B99 vehicles were unable to simultaneously pass through the narrow section of
            the driveway, therefore give way line markings will be provided at both approaches as well
            as convex mirrors to provide visibility of vehicles already entering the section.

            Issue: Vehicle Swept Paths
            5. Provide additional detail and an amended Vehicle Swept Paths Plan that demonstrates
            how the proposed carparks are functional. The additional detail and amended plan must be
            endorsed by a suitably qualified person (RPEQ – Registered Professional Engineer of
            Queensland) and include, but not be limited to:
            a. realistic starting and finishing vehicle locations;
            b. assume all neighbouring carparks are occupied;
            c. provide comment demonstrating if the proposed ‘Visitor’ parking is limited to ‘rear-in’
            only and what systems are in place to indicate this to visitors;
            d. demonstrate how a B99 vehicle can enter and exit the ‘Existing Dwelling Parking’ without
            the overhang of vehicle leaving the internal driveway; and
            e. demonstrate how a B99 vehicle can enter and exit the southern-most carpark outside
            ‘Unit B’.

            The swept paths have been updated to address the requirements of the RFI. Please refer to
            the appendices within the traffic assessment which provide the swept paths requested.

            Issue: Stormwater Discharge
            6. Provide an amended Stormwater Management Plan that demonstrates how stormwater
            collected on-site will be controlled, collected, and released without causing scour damage
            to neighbouring properties or creating trip hazards for pedestrians. The additional detail
            must be prepared by a suitably qualified person (RPEQ – Registered Professional Engineer
            of Queensland) and include, but not be limited to:
            a. provide comment on the water quality of the stormwater collected in proposed
            stormwater line ‘D’ that bypasses the bioretention swale;

            The drainage within this small area has been redesigned to fall to the bioretention area as
            overland surface flow ensuring this portion of the site no longer bypasses the treatment
            swale.




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            b. demonstrate the lid type of proposed stormwater structure 1/A and how the structure
            will be constructed to avoid trip hazards in the road reserve; and

            The pit within the road reserve has been updated to a closed manhole lid to minimise
            potential trip hazards.

            c. demonstrate that the existing services along the Myall Street frontage will not be
            impacted by proposed stormwater lines 2/A – 1/A and 1/A – EX/A (including vertical
            clearances).

            Sewer main depths from Unity Water and indicative water service levels have been added
            to the stormwater longsections to demonstrate clearance. The sewer main invert is located
            at a level of between 110.35m and 110.74m with approximate I.L. at the crossing point
            110.52m. The lowest invert for the proposed drainage line is 112.5m therefore the required
            cover over sewer is achieved.

            Water main depth has been assumed and may vary between 600mm and 1.5m along the
            frontage in accordance with the SEQ Water and Unity Water standards. The actual depth
            will require potholing by the contractor to confirm final levels prior to any future operational
            works commencing. An annotation has been added to the stormwater long sections noting
            that the contractor will be required to adjust the water services in accordance with Unity
            Water requirements levels to achieve the required cover should there be a service conflict
            within the road reserve with the proposed stormwater line.

            Issue: Stormwater Quality
            7. Provide updated plans, SWMP and MUSIC model which only applies nutrient removal
            rates for proprietary products if they have been verified through SQIDEP.

            Proprietary products have been removed from the treatment line. Modelling has been
            revised to take into account treatment from the proposed rainwater reuse tanks, as well as
            the treatment from the bioretention area which was found to achieve the required level of
            stormwater quality pollutant reduction for the site. Please refer to the updated SWMP for
            further details.

            8. Provide survey of the downstream existing pit in Myall St in order to demonstrate that
            the bioretention sub-soil drains can freely discharge.

            The configuration of the proposed bioretention area makes use of a drop pit to which the
            subsoil drains will discharge. Subsoil drains will have an invert of approximately 114.4,
            and the outlet invert from the pit will be at nominally RL 113.6. The surface level of the
            downstream kerb inlet pit has been identified as 113.13m from LiDAR topography being
            below the level of the outlet pipe from the site. The bioretention sub-soil drains will
            therefore remain free draining under the proposed conditions as the elevation of the
            pipes above the downstream levels prevents water being able to back up to the proposed
            design levels.



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            Survey of the downstream pit will be required with detailed design, however there is
            currently sediment build up within the pit which will require pressure jet cleaning to
            determine the invert and final connection level.

            Issue: Sustainable Building Design Code
            9. Provide updated plans and a SWMP which incorporates rainwater collection and reuse at
            the site, sufficient to supply external non-potable fixtures such as communal landscape
            irrigation and bin washdown.

            The plans and SWMP have been updated to demonstrate the rainwater collection and reuse
            proposed for the site. As described in the report, 11 units would nominally require a
            33,000kL reuse volume to comply with the accepted outcomes of the sustainable building
            code. The development proposes a total reuse capacity of 50kL of reuse storage in addition
            to the 50kL of rainwater attenuation proposed.

            Issue: Landscape Setbacks
            10. Provide plans or information demonstrating that meaningful landscaping in the form of
            tree species can be planted and maintained in the bio-retention swale. Specific attention is
            to given to screening of the building, common areas, driveways and retaining walls on site.

            The bioretention depth has been increased to a nominal 1m depth of filter media to ensure
            deep rooting plants and trees are able to be established within the bioretention swale. For
            further information, refer to the town planning response and architectural landscaping
            plans.

            11. Provide further sections/plans that detail the contours and levels of the adjoining site
            at 9 Myall Street in relation to the earthworks, retaining walls and fences proposed.

            The sections and plans have been updated information about the levels in the adjacent
            property. LiDAR data from the Noosa-Gympie 2015 aerial survey project has been used to
            supplement the survey data to provide this information. Due to the nature of LiDAR data,
            there are some minor discrepancies between the survey and lidar data levels, however for
            information purposes the data is considered to be suitably representative of the local
            conditions.

            Issue: Waste Management

            16. Provide a waste management plan for the site demonstrating that sufficient area is
            available on site for both general waste and recycling bins.

            A waste management plan addressing this request has been prepared for the development
            and is included within the attachments.




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            17. Detail the location of a bin wash down area on site.

            Please refer to the proposed development plans for the location of the bin wash down area.
            The wash down area is to be provided with a sump which will capture the dirty water and
            discharge it to the sewer within the site. The sump and drainage from the wash down is to
            conform to the hydraulic engineer’s specification.

            18. Provide amended plans that detail the relocation of the bin area away from the Maple
            Street frontage. In this regard a landscape setback is to be provided to Maple Street with
            the bins in a location not visible to the street.

            Refer to the updated plans which have relocated bins away from the frontage with a
            landscaped set back to reduce their visibility from the street.

            We believe that the above satisfactorily addresses the matters raised in the above
            information request however, should additional information be required, please contact
            our office directly.

            Yours faithfully,
            RECOR Pty Ltd

            Prepared by



            Ben Parry
            Civil Engineer
            BEng (Hons), MIEAust CPEng NER RPEQ
            RPEQ: 28084




P +61 7 5211 1003          A 75 Noosa Dr, Noosa Heads Qld 4567   E [email protected]   recorconsulting.com