22244-002-Rev1 Barina Ct

Mark Kussrow                                                                                    22244-002-Rev1
C/- CadCon Surveying & Town Planning                                                           26 February 2024




Text Figure 7: Slope/W output for existing dam wall – short term conditions

5.0        ENGINEERING ASSESSMENT
5.1       Dam Embankment Rehabilitation
To achieve a Low Risk against global instability for the main dam wall, the following rehabilitation works are
recommended:

          A civil/hydraulic RPEQ must complete an assessment of the catchment hydrology and anticipated
           flows. Subject to the results of the civil/hydraulic assessment, the existing spillway may need to be
           upgraded to ensure that a minimum freeboard of 1 m is maintained beneath the embankment crest,
           thus preventing water overtopping the embankment including during flood events.

          The surface of the dam embankment is to be protected from erosion by spreading topsoil to not
           more than 200 mm thickness and planting out using Lomandra Longifolia at spacings of about 1 m.

          Depending on the civil/hydraulic assessment and the anticipated stormwater flows, the existing
           channel along the embankment toe may also require upgrades to accommodate future flows during
           flood events. Stormwater flows must not be allowed to overtop the dam embankment crest or
           associated discharge channels.

          Areas exhibiting existing erosion scours within the main spillway discharge channel must be
           reinstated and protected from future erosion. The erosion protection required will be dependent on
           the anticipated stormwater flows which are to be determined by hydraulic analysis by a civil/hydraulic
           RPEQ. An indicative specification for rock fill is provided below, however the necessary grading for
           the rock fill should be assessed by a hydraulic or civil RPEQ prior considering anticipated stormwater
           velocities.




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