ADG Dewatering Management Plan · OPW21/0315

Cone of depression

DER requires a preliminary assessment of the radial extent of the cone of depression and
pumping rates and times for all dewatering operations in ASS areas.

Empirical methods to calculate the radial extent of the groundwater cone of depression and
pumping rates and times for dewatering operations are outlined in Appendix E of 8

Treatment and management of soils and water in acid sulfate soil landscapes 1.59 MB

(Published July 2011, Revised June 2015)

Calculator

Input

Length of excavation | 26
(metres):

Width of excavation | 22
(metres): -
Required groundwater 42
drawdown (metres):
Saturated thickness of
the unconfined
aquifer’ (metres):
Hydraulic conductivity |

of the aquifer (K) 0.000949
(metres per second):

1 46

| Calculate |

Results

Effective radius of
pumping well , Re
(metres):

Radius of influence of
dewatering, R.
(metres):

(i.e. radius of the cone
of depression)

Total pumping rate
(litres per second):
Time taken to establish
the cone of depression
(hours):

m/sec

13m

53m

12l/sec

25hrs