19553 - Erosion and Sediment Control Plan

Area 1B
T = 1 month
A = 2580m2
S = 1.26 (Ave slope 9.5%, length 129m)
K = 0.047 (inorganic clays of high plasticity)
H = 153

Total TASK number for area 1 = 229 – just exceeds low risk threshold of 200

Area 2 & 4

Area 2 and 4 drain to a common discharge point - existing dam in lot 9.

Area 2
T = 1 month
A = 2800m2
S = 0.73 (Ave slope 4.9%, length 200m)
K = 0.047 (inorganic clays of high plasticity)
H = 96

Area 4
T = 2 months
A = 3500m2
S = 0.21 (Ave slope 1.0%, length 100m)
K = 0.047 (inorganic clays of high plasticity)
H = 69

Total TASK number for area 2 & 4 = 165 – low risk

Area 3

Area 3
T = 1 month
A = 2000m2
S = 0.69 (Ave slope 8.1%, length 80m)
K = 0.047 (inorganic clays of high plasticity)
H = 102 – low risk

Area 5 (individual lot site – example)

T = 1 month
A = 1500m2
S = 0.73 (Ave slope 5%)
K = 0.047 (inorganic clays of high plasticity)
H = 51 – low risk



2. Sediment Basin Sizing
Even though most areas of the site can be considered a low erosion risk it is recommended that
traditional sediment basins be constructed where possible (Type D/F basins). Due the fact that the
majority of the disturbance is longitudinal in shape (ie following the road alignment), there is limited
opportunity and space to construct large sediment basins within the road area and such basins will
need to be removed to allow the road pavement to be constructed. It is envisaged that batters
associated with the road formation will be topsoiled and either mulched or hydromulched to stabilise
these areas prior to the sediment basin being removed to facilitate road construction.



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