3. Burrendong Dam
Asset Type Major Gated Dam
Customer Service
Area
Central
Valley Macquarie
Name of Waterway Macquarie River
Nearest Town Wellington
When
Commissioned
1967
GPS Latitude 32.41.136
GPS Longitude 149.07.986
Description of Dam
Rockfill with clay
core
Storage Capacity 1,188,000 ML
Catchment 13,900 km
2
Outlet Capacity 8,200 ML/day
Spillway Type
Gated concrete
chute
Power Station 19 MW
Crest Length 1,113 metres
Dam Height 76 metres
Current Usage
Water
Conservation
Town Water
Supply
Stock and
Domestic
Irrigation
Environmental
Flow
Hydro-Power
4. Windamere Dam
Asset Type Minor Ungated Dam
Customer Service Area Central
Valley Macquarie
Name of Waterway Cudgegong River
Nearest Town Mudgee
When Commissioned 1984
GPS Latitude 32.45.396
GPS Longitude 149.47.058
Description of Dam Rockfill with clay core
Storage Capacity 368,120 ML
Catchment 1,060 km
2
Outlet Capacity 2,333 ML/day
Spillway Type
Uncontrolled unlined rock
cutting
Power Station Potential [2 MW]
Crest Length 825 metres
Dam Height 67 metres
Current Usage
Water Conservation
Town Water Supply
Stock and Domestic
Irrigation
5. Wyangla Dam
Asset Type Major Gated Dam
Customer Service
Area
Central
Valley Lachlan
Name of Waterway Lachlan River
Nearest Town Cowra
When
Commissioned
1968 (gates
1971)
GPS Latitude 33.56.160
GPS Longitude 149.00.492
Description of Dam
Rockfill with clay
core
Storage Capacity 1,220,000 ML
Catchment 8,300 km
2
Outlet Capacity 6,700 ML/Day
Spillway Type
Gated concrete
chute
Power Station 18 MW
Crest Length
1,372 metres
(1.5 km incl
spillway)
Dam Height 85 metres
Current Usage
Water
Conservation
Town Water
Supply
Stock and
Domestic
Irrigation
Environmental
Flow
Hydro-Power
6. Carcoar Dam
Asset Type Minor Ungated Dam
Customer Service
Area
Central
Valley Lachlan
Name of Waterway Belubula River
Nearest Town Carcoar
When
Commissioned
1970
GPS Latitude 33.36.414
GPS Longitude 149.11.802
Description of Dam Concrete Arch
Storage Capacity 35,800 ML
Catchment 230 km
2
Outlet Capacity 1,470 ML/day
Spillway Type Free overflow
Power Station No
Crest Length 269 metres
Dam Height 52 metres
Current Usage
Water
Conservation
Town Water
Supply
Stock and
Domestic
Irrigation
7. Flood Warnings
Bureau of Meteorology responsibility
– They hold specific indemnity
– SWC does NOT issue flood warnings
– Should NOT estimate river heights under flood conditions
– it is NOT our role
– We work with the flood forecast group of BOM in NSW
– Also maintains close cooperation with State Emergency
services
15. BURRENDONG DAM
7 Radial gates - 16.76 m x 6.10 m
Full supply level - 1,190.060 GL
(344.733 m)
Flood level - 1,679.720 GL (350.829 m)
Top of gates - 1,706.890 GL ( 351.134
m)
Gates Withdrawn - 2,274.330 GL
(356.925 m)
16. BURRENDONG DAM
Irrigation Outlets - 3 x 60” Hollow Jet
Valves at full capacity 5,850 ML/d
1 x 30” By-pass Valve (335 ML/d)
1 Hydro (at full capacity 3,500 ML/d)
Optimum release at full capacity =
5,850+3,500+335 = 9,685 ML/d
17. General Information
During Floods low level valves may kept
open partially in order to flush out mud
and other debris
Graph A helps to determine amount to
be released
Graph B will tell you PI setting required
to release previously determined
amount
18. GATE OPERATION
Unlike Sector Gates which are
lowered, Radial Gates are raised to
release water
All 7 Radial gates are raised in
unison
When operating, storage releases
and gate openings are determined
by using Nomographs found in the
Flood Ops Manual
19. To maintain the safety of the Dam
at all times
Minimise the effect of the flood
peak downstream of the Dam. This
can be by either minimising the
peak outflow or delaying releases to
allow for D/S tributaries to subside
(This may need to be reassessed in
the future)
DAMOPERATING PROCEDURE
20. Procedural Rules
Always maintain 0.3 mitres of freeboard
Never allow the storage level to exceed
maximum permissible water level while
gates are still raised
Rate of outflow never to exceed the rate
of inflow until the flood has peaked
21. HOW PROCEDURES WORKS
It assumes inflow is at its peak at the time
of reading.
Adds on an average recession derived
from past floods
Works out how much Volume is in the
recession
Works out the gate opening needed so
that the expected future inflow can be
stored exactly in the airspace(pondage)
created by the raising of the gates
In these calculations it is assumed that the
storage will reach the maximum
permissible storage level at the time that
‘Inflow = Outflow’
22. CALCULATION OF INFLOWS
Estimated by calculating the apparent
inflow at the dam wall.
This is done by calculating the volume of
water that flowed into the dam in the last
time period (say 1 hour).
Total Inflow = rVolume + Outflow
23. TYPES OF PROCEDURE
Three Types of Procedures
Forecast Procedure
Aimed at achieving the maximum d/s
mitigation while still ensuring the safety of
the dam.
Use forecast flows both u/s and d/s,
rainfall information, info from a number of
other sources.
Emergency Procedure
Primary aim is to ensure the safety of the
dam.
Provide some d/s mitigation.
Crisis Procedure
Only aim is to ensure the safety of the
dam.
24. Airspace Operation Rules
(d) each bay shall have different maximum rates of releases, and
these releases which are above water orders, shall be equal to
the inflow up to the maximum combined release, plus
downstream tributary flow, and these releases shall be in
accordance with the following:
(i) bay 1—Burrendong Dam water storage between 100% and 120%,
and releases to a maximum of 5,000 ML/day at Warren, which
equates to approximately 5.5 metres at Warren town,
Orders + 700 to 1 400 ML/d
(ii) bay 2—Burrendong Dam water storage between 120% and 130%,
and releases to a maximum of 12,000 ML/day at Gin Gin, which
equates to approximately 6.5 metres at Warren town, and
Orders + 1 400 ML/d
Orders + 5 000 ML/d (if peak >131 %)
(iii) bay 3—Burrendong Dam water storage between 130% and 142%,
and releases to a maximum of 18,000 ML/day at Gin Gin, which
equates to the minor flood level of 7.5 metres at Warren town,
Orders + 5 000 ML/d
12 000 ML/d (if peak < 142 % & no flow @ Reddenville)
25 000 ML/d or D/S peak (if peak >142 % or flow @ Reddenville)
25. Airspace Operation Rules
release rates lower or higher than those indicated in
subclause (1) (d) for each FMZ bay may be made if:
(i) the release rate specified in subclause (1) (d) will cause
prolonged inundation of the floodplain and result in
economic losses to agriculture,
(ii) the release rates specified in subclause (1) (d) will restrict
landholder access to their properties for extended periods,
or
(iii) the environment and community would benefit from lower
or higher rates of release, and
30. Flood Levels at Dubbo
Minor - 5.5 m = 57,000 ML/d
if conditions permit, try to maintain
57,000 ML/d or lower at Dubbo
Moderate - 7.9 m = 94,500 ML/d
Major - 11.0 m = 237,000 ML/d
31.
32. Gate Operation
Graph A helps to determine amount to
be released
Graph B will tell you PI setting required
to release previously determined
amount
During Floods only low level valves are
kept partially open in order to flush out
mud and other debris
33. WYANGALA DAM
STRUCTURE
8 Radial gates - 14.63 m x 12.91 m
Full supply level - 1,217.670 GL
(378.854 m)
Top of gates - 1028.35 GL ( 379.158 m)
Gates withdrawn - 1284.07 GL (
380.073 m)
34. WYANGALA DAM
Irrigation Outlets - 2 Hollow Jet Valves
& 1 FDC Valve
– 1 x 30” Valve (640 ML/d)
– 1 x 60” Valve (3,400 ML/d)
– 1 x FDC Valve (3,100 ML/d)
Hydro A (at full capacity 2,600 ML/d)
Optimum release at full capacity =
about 7,000 ML/d
35. GATE OPERATION
Unlike Sector Gates which are
lowered, Radial Gates are raised to
release water
All 8 Radial gates are raised in
unison
When operating, storage releases
and gate openings are determined
by using Nomographs found in the
Flood Ops Manual
37. Wyangla Dam Capacity (%)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
Jun/01
O
ct/01
Feb/02
Jun/02
O
ct/02
Feb/03
Jun/03O
ct/03
Feb/04
Jun/04
O
ct/04
Feb/05
Jun/05O
ct/05
Feb/06
Jun/06
O
ct/06
Feb/07
Jun/07
O
ct/07
Feb/08
Jun/08O
ct/08
Feb/09
Jun/09
O
ct/09
Feb/10
Jun/10O
ct/10
Date
WyanagalaStorage(%)
38. Flood Levels at Cowra
Minor - 8.5 m = 47,800 ML/d
if conditions permit, try to maintain
47,800 ML/d or lower at Cowra
Moderate - 10.7 m = 85,300 ML/d
Major - 13.4 m = 239,000 ML/d
39.
40.
41.
42.
43.
44.
45.
46. EFFECTS OF SECTOR GATES
•Unlike Radial Gates, Sector gates are lowered to release water
How Procedure Works Standard schedule to fill in that guides user through the process. Each calculation follows the same steps and you end up with a series os stepped gate openings and therefore releases. It is a self correcting procedure ie. if an error is made in the current reading it does not carry through to the next. Each calculation is independent. Dam staff should fill in the emergency schedule (the operators will explain why different releases are being made).
INFLOWS Fluctuations that occur from time to time in the inflows need to be treated cautiously as they could occur for a number of reasons such as bad readings, storage reading inaccuracy, human error in calculations etc. Should always recheck the calculation and wait for another reading to confirm, or even do an earlier reading if confirmation is required quickly. Although not essential it is recommended that you plot the Inflow Hydrograph at the dam during an event.
Both Forecast and Emergency procedures are based on the same principles and techniques.
Both Forecast and Emergency procedures are based on the same principles and techniques.
Both Forecast and Emergency procedures are based on the same principles and techniques.
