Title

Farm Dam Boundaries 

Alternate title

FARM_DAMS 

Purpose

Use FARM_DAMS in conjunction with FARM_DAM_POINTS to visualise all man made waterbodies, including farm dams, across Victoria. This dataset based developed using source imagery captured approximately 2004 to 2010. 

Status

Completed  

Code

4283 

Maintenance and update frequency

Not planned  

Topic category

• Inland waters

Use limitation

General 

Classification

Unclassified  

Statement

Dataset Source: The FARM_DAMS and FARM_DAMS_POINT datasets combined include all man made water bodies in Victoria. Note that the term farm dams may be misleading - these layers represent all man made waterbodies, some of which are not necessarily for agricultural purposes. In addition, some may be natural features such as wetlands or lakes which were indistinguishable from man made waterbodies in the aerial imagery, and some may be large reservoirs. The State Government of Victoria commissioned a study to determine the location and impact of farm dams within Victoria. A large part of this study was the location and digitising of farm dam boundaries. For the sections of Northern Victoria within the Murray Darling Basin, these boundaries were created for a Geoscience Australia (GA) project. However, the data of capture for these dams is 2005 +/- 12 months. To address the data gaps in southern Victoria, all farm dam boundaries outside of the Murray Darling Basin were digitised to the same specifications as the GA data, using imagery from 2009/10. In addition, a sample area of approximately 6000 km2 was chosen in the MDB to investigate the level of change in farm dam development between 2005 and 2009. Update December 2018: The FARM_DAMS and FARM_DAMS_POINT layers were updated with improved attributes. The spatial data is unchanged, but attributes have been extended and field names changed to make the layers more useful. The new field names include: CURRENCY (approx date of source imagery) PLAN_ACCUR (approx planimetric accuracy) FEATSOURCE (data source used for digitising) BASIN (river basin) SDL_ID (matching SDL catchment identifier based on SDL_CATCH layer) VOL_ML_EST (estimated full capacity of dam im megalitres based on formula Vol = (SurfArea^1.32)/9600) SURFAREAM2 (surface area in square metres - for point features this surface area has been randomly assigned) FEAT_TYPE (feature type) ORIG_OBJID (unique identifier used as part of hydrological modelling for the Victorian Water Accounts) VIC_DAM_ID (unique identifier used as part of hydrological modelling for the Victorian Water Accounts) FARMDAM_YN (Yes or no flag to identify features which are genuine farm dams (Y) or features which are other man made waterbodies such as large reservoirs or treatment plant ponds (N)) RUNOFF_DAM (Yes or no flag to identify features which primarily harvest water from local surface runoff (Y) or which harvest water from other sources such as irrigation pipelines(N)) Dataset Originality: Primary 

Classification

Unclassified  

Attribute Quality

Comments

Not Known 

Positional Accuracy

Comments

Not Known 

Conceptual Consistency

Comments

Not Known 

Missing Data

Comments

Under the data collection specification for the original GA data, features were collected as either polygons or points depending on their visible area. The smallest features were collected as points and all other features were collected as polygons. Under the data collection specification for the Victorian data, all features were collected as polygons. Consequently, FARM_DAMS includes all waterbodies in southern Victoria and all larger waterbodies in northern Victoria. FARM_DAMS_POINT includes all smaller waterbodies in northern Victoria. FARM_DAMS and FARM_DAMS_POINT data sets should be used in combination to represent all features across the state. 

Excess Data

Comments

Not Known