How much water can the Lake hold?
The Lake Albert Management Plan estimates that when full, the Lake represents a storage volume of around 4,000 megalitres
How is the Lake filled?
The two primary sources for filling Lake Albert are
- Crooked Creek to the South East - partially diverted from 1902, and permanently diverted into the Lake in 1969/70
- Stringybark Creek to the South West - partially diverted in 1932 and permanently diverted into the Lake in 1977
Under average rainfall conditions, the catchment area has the ability to generate an inflow of more than twice the volume of water stored in the Lake.
Once the catchment area to the south of the Lake is saturated, these two sources can fill the Lake in a relatively short timeframe.
Recent works have been undertaken on these waterways to improve the quality of the water entering the Lake.
Has anything changed recently?
Over the past 10 – 20 years considerable soil erosion works have been undertaken in the catchment feeding the Lake. The catchment now needs some wetting through rainfall before the creek system will begin to flow.
Rainfall required to saturate the catchment does become much higher in periods of drought.
Where does the water go?
The main source of water loss is evaporation.
Normal evaporation losses are 1000 mm in an average year and up to 1500 mm in a drought year. This is equivalent to half the Lake’s capacity in a dry year.
Can the Lake be deepened to ‘drought-proof’ it?
Within the Lake Albert Management Plan it was estimated that Lake Albert has accumulated approximately a million cubic meters of sediment.
It was estimated that the cost to remove this in a single project would be in the vicinity of $20M.
Council conducted drilling and soil tests when the northern end of the lake was previously dry which allowed for the removal of sediment from this area in partnership with community volunteers.
What options has Council investigated to fill the lake?
The major challenge for Council is to find a solution that is both economically and environmentally sustainable in addressing the communities concerns regarding the management of the Lake. Council has explored a number of options in detail regarding filling of the lake. These include:
From the River?
Recent conversations with the relevant State Government departments have indicated that using river water to fill the Lake could be possible; however would require a significant Review of Environmental Factors before any application.
After the review providing all requirements could be met it is likely that the licence would be issued as a zero allocation licence meaning Council would then have to purchase water from the open market to use under this licence.
An alternative to this would be to purchase a licence on the open market which already has a water allocation.
The main obstacles of using river water are:
- the high cost of obtaining and maintaining a water licence,
- the ongoing water usage costs,
- the initial capital cost required to put in place the infrastructure necessary to be able to deliver the water
Cost estimates listed in the Lake Albert Management plan vary from $6,000,000 to $30,000,000 to implement this option.
There are three main aquifers within the city area, with one forming a water source for the city. Some of these aquifers are highly saline.
Any supply from a bore would be subject to licensing from the relevant State Government agencies.
There is currently no allocation or licence available to Council for this purpose and investigations on the suitability of using groundwater would need to be completed.
From treated effluent?
For public health reasons, recycled effluent for re-use in Lake Albert would need to be of a standard that is classified as Class A. Currently Council's treatment plant’s discharge is classified as Class B. Council sought funding to extend the Sewer 2010 project to allow plant to produce Class A water however was unsuccessful.
The Lake Albert management plan estimated at the time the cost to upgrade the infrastructure from Class B to Class A discharge would be $10M - $12M.
From stormwater diversion?
Council has investigated the possibility of diverting water into the northern end of the lake via the Tatton drain. Following these extensive investigations Council resolved at the Ordinary Council meeting held February 2011 not to proceed with the diversion.