Water Control Structures

Surface water management is needed wherever water erosion is a risk and where water movement control or water harvesting is required.

The guidelines here will help in choosing suitable earthwork structures, with links to detailed pages on those structures. Expert advice should be sought before constructing any earthworks, to avoid technical, environmental and safety risks associated with water management.

We recommend that any earthworks are part of an integrated water and salinity management program.

Surface water management options used in Western Australia

 
Earthwork

Land slope

(%)

Soil type

Grade

(%)

Landscape position Purpose
Absorption banks and level banks Up to 10     upper slope, below areas producing a lot of run-off controlling run-off water where a grassed waterway cannot be safely maintained
Grade bank Up to 10 shallow duplex / loam

0.2 to 0.5

upper and mid-slope

controlling surface water erosion; harvesting water from slopes
Dams (excavated earth tanks) Up to 10

clay / shallow duplex / deep duplex / loam

Up to 10

not in valley watercourse

storing and providing access to water for agricultural or household use
Roaded catchments Up to 6

clay / shallow duplex

Up to 6

good clay required close to surface

improving water run-off from reduced catchment areas into dams
Grassed waterways         providing safe disposal of overflow from dams or discharge from the end of grade banks
Seepage interceptor bank Up to 10 shallow duplex / deep duplex / Sand  

lower and mid-slope

controlling shallow seepage and waterlogging
Broad-based banks 2 to 6 shallow duplex / loam

0.15-0.3

upper, middle and lower slope

controlling surface water erosion; allowing easy vehicle traffic across banks

Shallow relief drains

(W drain, V drain, spoon and spinner drains)

Up to 0.2

clay / shallow duplex

Up to 0.2

valley floor

removing surface water from flooded areas
Levee waterways Up to 10

clay / sand / deep duplex / shallow duplex

Up to 10

valley floors and hill slopes

guiding and controlling the spread of water in drainage lines
Raised beds 0.1 to 2  

0.1 to 2

  raising seed beds above the saturated soil of waterlogged areas
Evaporation basins Site specific       holding saline discharge and preventing salt discharge to environmentally sensitive areas


Layout of surface water earthworks



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