Risk of Spill Information for the Campaspe system

Friday 10 September, 2021

The risk of spill in the Campaspe system at 10 September 2021: 20%

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 1 September 2021: 147,283 ML

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

Inflow for the June – August 2021 period is indicated by the red line: 60,827 ML

The volume difference at Lake Eppalock between full supply and the storage volume on 1 September is indicated by the green line: 147,283 ML.

Notes for charts:

There are 128 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 June to 31 August in each of those 128 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 water year (2021).

The second chart displays the volume of inflow to Lake Eppalock for the period 1 September to 31 December in each of the 128 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 September 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 June to 31 August will be greater than 50,000 ML in any given year is close to 45%.

Additional notes:

  • The volumes in spillable water accounts can change due to seasonal determination increases.
  • The 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.