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 |
| (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
Also, read Soil Conservation Earthworks Design Manual
Source: https://www.agric.wa.gov.au/water-erosion/surface-water-management