Bureau of Meteorology logo
 
                           

Sydney

                                                                                                   

1.2 Unregulated channel

                             

Supporting information   


Details of the volume of water stored in unregulated river channels are shown in the following table.  The volume is an instantaneous estimate of static volume held in the river reaches.  It is not the total volume flowing past a point during 2009–10.

River*

From

To

Volume (ML)

30 June 2009

Volume (ML)

30 June 2010

Capertee

Glen Davis

Upper Colo

540

247

Coxs

Lithgow

Kelpie Point

143

76

Macdonald

Howes Valley

St Albans

10

2

Shoalhaven

Kadoona

Fossickers Flat

583

1,047

Wollondilly

Pomeroy

Golden Valley

74

93

All above

1,350

1,465

* Only the river sections for which data are available are included. Information about the river sections that were identified as water assets but could not be quantified is provided in the note Significant water accounting policies.

 

Quantification approach   


Data source

The NSW Office of Water: Hydstra and ‘Computer Aided Improvements to River Operations’ (CAIRO) databases.

 

Data provider

The NSW Office of Water

 

Method

Derived from measured data

For each river section S(n):

V = Q x T

The River Channel Storage will be equal to the sum of all river section volumes.

River Channel Storage = ∑ S(n) V

 

Symbol

Variable

Unit

Q

Average flow in the river section; calculated by averaging the daily flows at the upstream and downstream river gauges.

ML/d

V

Volume in each river section.

ML

T

Average travel time for a parcel of water to travel through the river section.

days

 

Uncertainty

The volume was estimated from measured data. Estimated uncertainty is in the range +/–50%, based on professional judgment with conservative uncertainty estimates of +/–10% and +/–50% for flow data and travel time, respectively.

 

Approximations, assumptions, caveats/limitations

  • Travel times are estimated to the nearest day.
  • Daily flow change between gauging sites is assumed to be linear.