Garden Drainage Repair - Capital or Deductible

What's the consensus on this scope of work from the experts? .

Property is < 4 yrs old, and the quality of the work of the original builder is probably questionable. My initial thoughts were restoration to original condtion, hence deductible, but would the ATO argue that other than the 1m3 of garden soil and mulch, the rest is an improvement to get the drainage to work properly? (And if so, then the question is appportionment of the $2500 cost - there was probably a lot of labour involved to transport the mulch and soil to the garden, )



Drainage Issue:
As per site inspection the 100mm x 100mm black box drain along the rear fence in
garden bed is not doing anything due to the current condition of this drain
installation. This is allowing all sub-soil/ above ground water from rear neighbours
to flow under fence over drain and onto rear patio area in heavy down pores.
Scope of Work:
Remove existing box drain/concrete along bottom of fence. Excavate ground.
Supply 100mm x 100mm everhard black box drainage as per existing and set drain
in a bed of concrete along rear fence line as per existing location. Supply 200mm x
50mm sleepers and secure them to the inner face of the box drain- closest to
building to stop volume of water to rear garden/patio area from neighbours.
Approx: 12lm of timber edging. Supply new box drain, concrete.
Supply approx: 1m/3 of garden soil and level out to garden where ground has
eroded over time. Supply cypress mulch and level out to all gardens to increase
presentation of gardens/weed control.
Note
Access is limited via high fence down side of building. Manual labour to carry out
all works due to location of garden/back fence.

 

Looks partially like eligible Div 43 capital expenditure. As you say its an impovement cost > $300
You may have trouble apportioning a invoice worded that way.

 

Thanks!