Managing subsurface water

Page last updated: Wednesday, 12 December 2018 - 3:23pm

Managing subsurface water can help to lower watertables and alleviate problems with waterlogging, rising salinity, and infrastructure damage.

Many of the technologies on this page require the Commissioner of Soil and Land Conservation to be notified, especially when the subsurface water is discharged in a way that is likely to cause concern off-site.

We recommend that subsurface water management is part of an integrated water and salinity program.

Some of these activities are covered by legislation

An owner or occupier of land must give at least 90 days notice to the Commissioner of Soil and Land Conservation of an intent to drain subsurface water to control salinity and discharging that water onto other land, into other water or into a watercourse, even on the same property. The notice must be in writing using the notice of intent to drain or pump (NOID) form. Principles and guidelines for inland drainage are covered in the Policy framework for inland drainage.

Management options

Option Land
slope
Soil
type
Fall grade Landscape
position
Purpose                                                                      
Open deep drain less than 0.2% see link page less than 0.2% lower landscape, valley floors

A channel used to intercept groundwater and discharge that water to a safe point. Open deep drains also allow inflow of surface water. Usually constructed to 1 to 3m deep to manage salinity and waterlogging.

Notifiable

Leveed deep drain less than 0.2% see link page less than 0.2%

lower landscape, valley floors

A channel used to intercept groundwater and discharge that water to a safe point. Leveed deep drains prevent inflow of surface water which reduces erosion of the drain batters. Usually constructed to 1 to 3m deep to manage salinity and waterlogging.

Notifiable

Pumping groundwater site specific

site specific

site specific

site specific

Used to drawdown the watertable (saline or fresh) to manage salinity and waterlogging under potentially productive land.

Notifiable

Desalination of groundwater or surface water

site specific

site specific

site specific

site specific

Used to produce product water of lower salinity level and brine discharge.

May be notifiable; contact the Commissioner (see Contacts below)

Siphon 1.5–2% Upslope seepages 1.5–2% In or below seepages in the higher landscape

Used to safely move saline or fresh water from higher in the landscape to safe disposal points lower in the landscape.

Notifiable

Relief well / bore       lower landscape

Used to release artesian pressure in groundwater that is leading to saline discharge.

Notifiable

Mole drain less than 2% clay / heavy loam

same or less than landslope

waterlogged heavy soils

Used for removing water from saturated clay soils. These drains are practical and relativel cheap for the close spacing required on saturated clay soils.

Notifiable in the gazetted Peel–Harvey Catchment

Evaporation basin and pond site specific clay no fall site specific

Used to hold saline discharge and prevent salt discharge to environmentally sensitive areas. They are part of a salinity management system. 

Notifiable

High water use vegetation recharge or discharge areas, independent of slope usually lighter textured soils   recharge or discharge areas Not notifiable because there is no saline discharge.

Contact information

Richard George
+61 (0)8 9780 6296
Commissioner Soil and Land