Field measurement guide
Farm water calculator: additional information
Field measurement guide
Measuring dam depth
Agriculture Victoria has developed a simple tool to measure the depth of your dam. The tool called DAMDEEPconsists of a hand reel, float, beads and a sinker. It is easy to make by following the instructions in this video. Measuring the depth of your dam.
Catchment area
The catchment area is the total area of land that contributes runoff into a dam. It can be estimated with the aid of aerial photos, topographical maps or a range of online mapping programs. If a topographical map is used, the flow of water will follow the steepest slope which is where the contour lines are closest together. For more information about reading contour maps please refer to https://www.ipswich.qld.gov.au/__data/assets/pdf_file/0017/8810/activity_sheet_1_understanding_catchments.pdf
Units of measurement for water volumes
- 1,000 litres = 1 kilolitre (KL or cubic metre m3)
- 1,000,000 litres = 1 megalitre (ML) which is approximately an Olympic sized swimming pool
- 4.55 litres = 1 gallon (Australian)
Information required about your property | ||
|---|---|---|
Annual rainfall (mm/year) | mm/yr | |
Annual PAN evaporation (mm/year) | mm/yr | |
Stock type | Number of animals | |
List each type of stock class such as milking cows, steers, nursing ewes. | Maximum number of animals now or in future. | |
Number of household members | ||
Area of each garden type in metres squared (m2) | ||
Native Garden | (m2 | |
Lawn with Shrubs | (m2 | |
Vegetable Garden | (m2 | |
Other Garden | (m2 | |
Other use of water: dairy shed (please refer to publication Dairy Shed water how much do you use?' search ‘dairy shed water use’ for help estimating dairy shed water use) | ML/year | |
Other use of water: | ML/year | |
Other use of water: | ML/year | |
Method for measuring ‘other uses’ and ‘other sources’ of water
Method 1 – flow rate method – is used to measure the flow of water from a hose or pump. It requires a stopwatch and a container of known volume, and knowledge of how long the water is used for.
Volume of measuring container in litres (L) | Litres |
Time taken to fill container (secs) | Seconds |
Estimate minutes/day the water is used on this 'other use' | Mins/day |
Estimate the number of days/year the water is used on this 'other use' | |
Litres of container divided by time taken to fill | L/second |
L/second multiplied by 60 seconds | L/minute |
L/minute multiplied by average minutes spent using 'other use' water | Litres/day |
L/day multiplied by days/year the task is undertaken (divide by 1,000,000 to convert to mega litres) | ML |
Method 2 – tank volume method – can be used when water is stored in a tank or container prior to being used. The volume of water in the tank needs to be determined and then the proportion of the tank used is then applied.
Dams
For square/rectangular and gully dams, measure the dam length and width in metres and for circular dams the diameter. The dam depth will also be needed for all dam types, use the dam depth measuring hand reel and float that you've made to undertake these measurements.
Dam volume and catchment yield | ||||||
|---|---|---|---|---|---|---|
Dam name | Dam type | Depth (m) | Top dam dimensions (metres) | Catchment area (hectares) | ||
Width | Length | Radius | ||||
e.g. circular, rectangle, gully | For circular dams, radius is half of the diametre or width | |||||
Tank Volume and Roof Yield | ||||
|---|---|---|---|---|
Tank or roof name | Tank volume (litres) | Tank height (height) | Radius (metres) | Roof area (m2) |
Please list if known, otherwise measure diameter and height of tank | Half of the diameter (width of tank) | Length (m) x width (m) | ||
Other water sources | ||
|---|---|---|
Source type | Description | Volume |
List water sources such as spring, watercourse, groundwater, town mains | Provide a brief description of water source such as quality and reliability | Use flow rate or tank volume method as described above to measure if this is possible. If not describe roughly how often the source is used. |