WRAM

Software

Support

Contact

Phone: 1300 5 WATER (1300 5 92837)
Email: support@ewater.org.au

eWater
Innovation Centre
University of Canberra
ACT 2601
www.ewater.org.au

Features and Limitations

Input Data

WRAM attempts to provide a link between hydrologic network models and economic models for resource allocation. As such, WRAM requires an extensive data set specifying both hydrologic relationships and economic activities. For convenience, the inputs to WRAM are grouped according to their likely source under three headings: hydrologic, economic and parameters.

Hydrologic data requirments

One of the distinct features of WRAM is that it draws extensively from the data set required to implement hydrologic network models such as IQQM. Data in this group are:

Layout of water demand nodes in the network.
Grouping of nodes limited by delivery constraints.
Maximum irrigable area of each node (ha).
Licensed volume of water (ML) associated with each node.
Maximum water requirement at each node (ML/ha/day).
Pumping capacity at each node (ML/day).
Channel or delivery capacity of each group of node(s) (ML/day).

Economic data requirements

Yield of each crop (tonnes/ha).
Crop price ($/tonnes).
Water charge ($/ML).
Variable cost of production other than water ($/ha).
Water requirement during the growth season (ML/ha).
Input-output transaction tables and water accounts for non-WRAM sectors are required for input-output analysis.

Data on the first four items can be obtained from farm budget information for regional agronomists and agriculture economists. Data on water requirements for individual crops is available either from hydrologic network models or from regional agronomists and agriculture economists. Data on crop water requirements on needed on a monthly or annual basis.

WRAM Parameters

Parameters in WRAM are:

For each node, specify whether or not water entitlement can be traded.
For each crop, specify the lower and upper limits within which crop production is allowed to change.
For each crop at each node, specify the initial crop mix and the lower and upper limits to the mix.

Output Data

Output using the WRAM Windows interface covers four main areas:

Summary information

Of particular interest is the shadow water price in $/ML. The shadow price of water is the marginal increase in the net benefit ($) per unit increase of water allocation (ML). In the absence of an established water market, the shadow price is the best indicator of the marginal value of water. The shadow price of water increases as water becomes scarce. The shadow price of water is zero when water availability is no longer a limiting factor to crop production.

Water trading

The water trading window shows the water surplus and deficit in ML in tabular and graphic forms. Water trading is theoretically possible only when the surplus equals the deficit and the shadow price of water is greater than zero.

Crop mix

The crop mix window shows the optimal decision in terms of cropping areas and crop mix for each node in tabular and graphic forms.

Water account

Water account shows the water requirement for each crop group in ML in tabular form. This information is required later on for input-output analysis.

Input-output analysis

The main outputs from input-output analysis are industry multipliers and water multipliers.

Caution Notes For User

The following assumptions were made when developing WRAM to simulate water reallocation and trading:

All water licence holders associated with a water demand node are represented as a single water trader.
Water is demanded by all nodes where water trading is allowed.
All traders in the market are price takers.
All traders possess perfect information.
Property rights are exclusive, transferable and enforceable.
Water rights are homogeneous and tradeable in standard units.
Transaction costs are nil.

Known limitations of WRAM are as follows:

Current configuration of WRAM can handle at least 58 water demand nodes and 50 separate crops in a project. The number of non-zeros in the A matrix for the LP is about 11,000. Internal parameter space requires adjustment once these limits are exceeded. Other limitations of WRAM are:

The maximum character length for names of node group and crop group is 10.
The maximum character length for node and crop names is 20.
The maximum character length for file names is 40.

There are no internal, fixed parameter values in WRAM.