RFI - Att 1 - Slope Stablility Assessement

4.       Recommendations
General recommendations to help maintain the stability of the site are given in the document Some
Guidelines for Hillside Construction, which is attached.
Construction of the proposed dams, as described in Section 1.1, shall not be altered from the referenced
Bax design unless assessed and approved by Tectonic prior to construction.
Please note that this assessment is provided based on the implementation of the following conventional
dam maintenance measures:
    Access to the dams should be maintained to allow monitoring inspections and minor reactive
     maintenance works.
    Trees should not be planted on the filled zone within 10 m of the northern side of Dam 01. Tree
     roots can cause leakage and erosion of filled dam walls.
    Any debris which builds up in the spillway channels running from the dams should be removed to
     prevent overflow and potential erosion of the surrounding areas.
    A maintenance inspection of the dams should be made following any rainfall exceeding 100 mm
     within 24 hours, during which the spillways and earth embankment should be assessed, as discussed
     below. It is recommended that dam inspections should be undertaken by the property owner.
    During monitoring inspections, the embankments should be examined for signs of erosion, cracking,
     piping, settlement, slides, and development of seepage (on the downstream face). Any cracks
     should be filled immediately with well compacted clay. There are three main kinds of cracks:
     transverse, longitudinal and shrinkage. Transverse cracks are those that run straight through the
     dam from the upstream to the downstream side. Longitudinal cracks develop parallel to the crest
     length. Shrinkage cracks develop in a random pattern of both transverse and longitudinal defects.
     Cracks can also lead to another kind of failure known as piping, which is a term used when seepage
     water creates a tunnel or pipe along a line of weakness through the dam.
    Some minor erosion may occur over time from the spillway channel banks, particularly during
     prolonged and/or intense rainfall events. It is expected that this would be limited to relatively small
     volumes of soil in any singular event. Should any significant erosion or instability occur, or signs of
     potential instability be observed, Tectonic should be notified immediately to arrange a site
     inspection and determine an appropriate course of action.


5.       Limitations
Your attention is drawn to the document Limitations, which is attached to this letter report.
This assessment relates only to the proposed works as described in Section 1.1. Any alterations to the
proposed development such as location and extent of earthworks must be assessed and approved by
Tectonic prior to construction.




18 March 2026
25029-002-Rev0                                                                                      11 of 12