Risk of Spill Information for the Campaspe system

Tuesday 10 October, 2017

The risk of spill in the Campaspe system at 10 October 2017: 22.0%

This value represents the percentage of years that spills occur from GMW’s share of Lake Eppalock taking into account the current storage volume, storage releases, inflows and evaporation from the storage using the historic data available.

Note: 10% or lower is the threshold for a declaration that would return water quarantined in spillable water accounts to allocation bank accounts.

Volume needed to fill Lake Eppalock at the time of assessment: 21,517 ML

Click here to find the current volumes in Campaspe system spillable water accounts. 

Ranked historic inflow to Lake Eppalock

Inflow for the July – September 2017 period is indicated by the red line: 32,980 ML

Ranked historic inflow to Lake Eppalock 

The volume difference at Lake Eppalock between full supply and the storage volume at the time of assessment is indicated by the green line: 21,517 ML.

Notes for charts:

There are 125 years of historic inflow data available for Lake Eppalock (inflow data for the period before the construction of the dam are based on modeled inflows). The first chart displays the volume of inflow to Lake Eppalock for the period 1 July to 30 September in each of those 125 years. The volumes of inflow shown are ranked in order from lowest to highest with the red line representing the volume of inflow recorded for the period in the current year (2017).

The second chart displays the volume of inflow to Lake Eppalock for the period 1 October to 31 December in each of the 125 years of historic data. The volumes of inflow shown are ranked in order from lowest to highest. The volume difference at Lake Eppalock between full supply and the storage volume on 1 October is indicated by the green line.

Probability of exceedance: Probability that the volume of inflow will be equal to or greater than a specified volume in any given year. For example, in the first chart, the probability that inflows to Lake Eppalock from 1 July to 30 September will be greater than 50,000 ML in any given year is ~55%.

Additional notes:

  • The inflow information provided here for the Campaspe system does not take into consideration the storage sharing arrangements at Lake Eppalock between GMW and Coliban Water.
  • Current year inflows are based on operational data.