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Presentation
The Gold Creek dam was designed by John HENDERSON (1836-1916) for the
Brisbane Board of Waterworks (WHITMORE 1996,
COSSINS
2000). The purpose of the dam was to increase the water supply for
the city of Brisbane. The dam built between 1882 and 1885 is an
earthfill
embankment with a clay puddle corewall . It was built under the general
supervision of HENDERSON and the site engineer was Alexander STEWART
(1843-1900).
The length of the dam is 187-m (624 ft) and the maximum height of the
embankment
is 26-m (86 ft). The reservoir storage capacity is about 1.8 10+6 m3.
The
catchment area is 10.48 km2 of protected forest area.
An overflow spillway is located on the left abutment on rock
foundation.
An outlet tower was built between 1883 and 1885 to draw water from the
reservoir. The original structure in cast iron failed in 1904,
following
improper operation while the reservoir was empty. The structure was
replaced
by the present concrete structure built in 1905.
Originally, the Gold Creek reservoir supplied water directly to the
city. In 1928, the reservoir was connected to Enoggera reservoir via a
tunnel beneath the ridge separating Enoggera Creek and Gold Creek
basins.
The Gold Creek dam acted as an upper reservoir for the Enoggera
reservoir
as the Gold Creek reservoir is located close to and at a higher
elevation
than the Enoggera dam. Nowadays the Gold Creek reservoir is no longer
in
use, the pipeline having been decommissioned in 1991. The reservoir is
managed by Brisbane
Forest Park, and it
was kept nearly full until early 2004
when the water level was artifically lowered for dam safety.
The spillway system
The Gold Creek catchment area and the neighboring Enoggera Creek basin
can be subjected to very intense rainfalls : e.g., 920 mm during a
storm
on 24 January 1974. Since dam construction, the spillway has been
modified
four times essentially, each time to increase the discharge capacity (CHANSON
and
WHITMORE 1998).
The
original 1885 spillway was a crude channel cut in the left abutment. In
1887, the spillway channel was widened by 15 m. In January 1887 and
March
1890, large overflows occurred and the unlined rock spillway was badly
damaged (CHANSON and WHITMORE 1996). As a
result
it was decided to build a masonry spillway in 1890. The design was
approved
by J. HENDERSON and the drawing of the spillway was signed by A.
STEWART. It is believed that the contractors for the spillway were
COWLEY
and ANNEAR. The 1890 spillway was a staircase structure made of
concrete,
the concrete aggregate being obtained from the original spillway rock
material
. The final staircase structure had twelve steps (1.5 m high) although
some original drawings showed originally 19 steps. In 1920, a low
concrete
wall was built across the spillway crest to increase the reservoir
capacity.
It was dismantled in 1932 (WHITMORE 1996). In
1975, the level of the spillway crest was lowered by 1.2-m (4 feet) to
increase the maximum discharge capacity but the steep channel was
unmodified. In 1998, the spillway crest was lowered by another 0.3 m.
Today's
spillway consists of the 1998 crest followed by the 1890 stepped
channel,
although a 5 m cut in the middle of the spillway crest was made in 2004
to
lower the water rervoir.
The maximum discharge capacity of the 1890 spillway was probably
selected
to pass the maximum observed flood at the time : i.e., 170 m3/s in
January
1887. The "theoretical" discharge capacity of the 1975 and 1998
spillways
is much larger (360 m3/s for 1975 crest design, ~600 m3/s for 1998
crest
design). But
CHANSON and WHITMORE (1996,1998)
showed that the maximum capacity of the stepped channel is 280 m3/s.
For
larger discharges, overtopping of the right sidewall would occur,
causing
unacceptable scouring and erosion at the embankment dam toe.
Discussion
Since Antiquity, dam engineers learned the risks of dam erosion and
destruction associated with large floods, and it was usual to design
dams
with a spillway system. In most early dams, the waters were discharged
over the dam crest or beside the dam. In ancient structures, a stepped
spillway design was selected to contribute to the stability of the dam
and simplicity of shape (CHANSON 2001). Later
design engineers realised the advantages of stepped channels for energy
dissipation purposes and to prevent scouring.
During the 19th century, overflow stepped spillways were selected
frequently,
with nearly one third of the dams built in USA being equipped with a
stepped
cascade. Most structures were masonry and concrete dams with a
downstream
stepped face reinforced by granite blocks (e.g. Goulburn
weir). Some dams were equipped with stepped rocklined spillways :
e.g.,
Ternay and La Tâche dams.
Others
had a lateral spillway (e.g. Le Pont dam).
Earth
embankments were usually equipped a lateral spillway (e.g. Val
House
dam, Gold Creek dam). The development of stepped spillway was marked by
two milestones : the Gold Creek dam cascade (1890, Australia) and the New
Croton dam (1906, USA). It is believed that the Gold Creek cascade
was the world's first concrete stepped spillway and the ancestor of modern
RCC
stepped spillways (CHANSON and WHITMORE 1998). Completed in
1906,
the New Croton dam spillway is probably the first stepped chute
designed
specifically to maximise energy dissipation. It is still in use despite
a major accident in 1955 (CHANSON 2001).
The educational role of
Gold
Creek dam and spillway
Water
supply in Australia is limited because of the dry climate. Hydraulic
engineering expertise is therefore critical to the country's future
developments, and most undergraduate civil and environmental
engineering
curricula in Australian universities include a significant hydraulics
component. At the University of Queensland, hydraulics and water
resource engineering are lectured in the civil and environmental
engineering curricula. The lecture material is structured to guide the
students from the basic principles of fluid mechanics to their
application to engineering design (CHANSON 2001b).
The
focus is on the basic understanding of fundamental principles and
their sound applications to real-world applications. In the context of
undergraduate and postgraduate subjects, design
applications in classroom are restricted to simple flow situations and
boundary conditions for which the basic equations can be solved
analytically or with simple models. Field work activities (Photo
No. 3) are essential to
illustrate real professional situations, and the complex interactions
between all engineering and non-engineering constraints (e.g. CHANSON
2001,2004). For example, the
construction of a dam and reservoir across a river involves first a
study of the stream hydrology and catchment characteristics, while the
design of the weir is based upon structural,
geotechnical and hydraulic considerations. A
consequent cost of the structure is off course the spillway, designed
to
pass
safely the maximum peak flood. In addition the impact of the weir on
the upstream and downstream valleys must be considered.
Although
first introduced to motivate students' interest, field studies in
undergraduate hydraulic courses have been an integral part of the
teaching pedagogy for more than ten years at the University of
Queensland (CHANSON 2004). Gold Creek dam is
one of the best field study sites for University students based in
Brisbane . Photo No. 4 and Photo
N. 5A show respectively E2408
Hydraulic design students and CIVL3140 Open channel flow students
inspecting the Gold Creek dam and its spillway system under the expert
guidance of the writer. Key features of the main spillway include a
55-m wide 60-m long broad crest, a stepped chute completed in 1890 and
the absence of downstream stilling basin. During the field work,
students surveyed the broad-crest, inspected the steep stepped chute
and investigated the downstream energy dissipator (Photo
No. 5B).
Students can become thrilled by relevant field studies directly
relevant to the course material and Gold Creek dam field studies are no
exception. For example, a broad-crested weir is often perceived as a
"dull" structure in the classroom, but it may become a
fascinating hydraulic structure in the context of a hydraulics field
work, particularly with large structures (Photo
No.
5B). The students gain also
first hand experience on real-world issues associated with a hydraulic
structure design. At Gold Creek dam, these include road access (incl.
road submergence during
floods), earth embankment dam design, concrete durability (1890
concrete steps) and spillway refurbishments.
Note that the pedagogical role of the Gold Creek dam and spillway
have been acknowledged in publications by the American Society for
Civil Engineers (Journal of Hydraulic
Engineering, Dec 2001 &
Journal of Professional Issues in
Engineering Education and Practice,
Oct. 2004), while photographs of Gold Creek dam student field trips
were published in a number of textbooks (e.g.
Elsevier-Butterworh-Heinemann
2004, Balkema 2001).
Summary
In summary, a University of Queensland team lead by Hubert
CHANSON has investigated the historical
development of the Gold Creek dam stepped cascade and its hydraulic
characteristics. The University study suggests a sound design of the
dam and the cascade, a 1890 cascade design based on Australian and
overseas experience (Victoria, Great Britain, France).
Unique features of the stepped spillway include the only stepped
cascade built in Queensland before 1900, and the world's
first use of non
reinforced concrete as construction material for a stepped spillway.
The stepped spillway is a superb example of Engineering Heritage
considering its safe operation for more than a century and the sound
cascade design by today's standards. It is the strong belief of the
writer that the Gold Creek dam stepped spillway should be heritage
listed, and that its international significance be recognised by local,
state and federal governments in Australia.
Further the Gold Creek dam and its spillway system are unique
educational and pedagogical facilties to further the education and
expertise of future graduates and professionals.
Timber crib weirs
Whetstone weir (Inglewood QLD,
Australia
1951) at low flow (H. CHANSON, Feb. 1998) - Timber
crib stepped
weir (H = 5 m) on the Macintyre Brook, completed in 1951. A major flood
occurred in 1956, the maximum recorded stream height being 11.8 m at
Inglewood.
Silverleaf weir (Murgon QLD,
Australia
1953) (H. CHANSON, Nov. 1997) - Timber crib stepped
weir
(H = 5.1 m) on the Barambah Creek. More about Timber
crib
weirs ...
Cunningham weir (Texas QLD, Australia
1953) in operation (H. CHANSON, Feb. 1998) -
Timber-crib
stepped weir (H = 4 m) on the Dumaresq river, completed in 1954. During
a major flood in 1956, the maximum recorded head-above-crest reached
7.3
m. The weir was little damaged and it is still in use. See listing in Structurae.
Greenup weir (Inglewood QLD,
Australia
1958) at low flow (H. CHANSON, Feb. 1998) - Timber crib
stepped
weir (H = 5 m) on the Macintyre Brook, completed in 1958, upstream of
Whetstone
weir. More about Timber
crib
weirs ...
Modern stepped spillway systems
New Croton dam stepped spillway (New York NY, USA 1955).
Photo
No. 1 : in July 1999 (Courtesy of Mrs J. HACKER) (Ref.: CHANSON
1995, Pergamon, pp. 189-191).
Joe Sippel weir (Murgon QLD,
Australia)
in November 1997 (H. CHANSON) - Completed in 1984, the 6.5-m high
stepped
weir is used for irrigation and water regulation purposes. The
structure
was built of steel sheet piles and concrete slabs. It is located
upstream
of the Silverleaf weir.
La Grande 2 spillway (Québec,Canada) -
Unlined rock stepped cascade in operation in 1983: Photo
No.
1, view from downstream (Courtesy of Michel Lefebvre) - Photo
No.
2 : view of the upstream steps (Courtesy of Michel Lefebvre).
Melton dam overflow stepped spillway (Melton VIC, Australia
1916). The Melton dam is an earthfill structure.
Completed
in 1916, the dam was heightened twice because of the rapid reservoir
siltation.
During the last refurbishment in 1994, an overflow stepped spillway was
added.
Photo No. 1 : general view (30
Jan. 2000). Photo No. 2 : details
of
the dam overflow spillway (30 Jan. 2000). More about
Extreme
reservoir siltation ...
Riou dam (France 1990). RCC stepped spillway :
h = 0.43 m. Photo No. 1 : view
from
downstream at sunset (photograph taken in Nov. 1994). Photo
No.
2 : view from right bank (photograph taken in Nov. 1994). Photo
No.
3 : view from the right bank of the crest, chute and stilling
basin
in June 1998. Photo No. 4 : view
from
downstream in June 1998. More
information ...
Santa Cruz arch dam stepped spillway
(New Mexico, USA). Completed in 1929, the Santa Cruz
dam
was a masonry arch dam. In 1987, the dam was reinforced by concrete
buttresses
and roller compacted concrete. A new overflow stepped spillway was
built
between two buttresses (Design: 56 m3/s) (Courtesy of US Bureau of
Reclamation
and John LABOON). More information
...
Jordan II weir (Gatton QL,
Australia
1992). Reinforced-earth stepped overflow weir (H = 5.3
m).
Photograph in Feb. 1998.
Brushes Clough dam spillway (1859-1991).
Overflow
embankment spillway system with precast concrete blocks. Photo
No.
1 : General view in 1993 (Courtesy of Mr GARDINER, NWW). Photo
No.
2 : details of the concrete blocks, showing the drainage holes
(Courtesy of Mr GARDINER). More about Embankment
overflow
stepped spillways: earth dam spillways with precast concrete
blocks...
Zaraysk dam (also called Laraisky),
Russia (Courtesy of Prof. Y. PRAVDIVETS). Overflow
embankment
spillway made of precast concrete blocks.
Loyalty Road Flood Retarding dam spillway (Sydney NSW,
Australia,
1996) - Photo No. 1
:
view from the right bank (Courtesy of D.Patrick JAMES). Photo
No.
2 : view from downstream (Courtesy of D.Patrick JAMES). Dam
height
: 30 m. RCC construction. Spillway capacity : 1,040 m3/s. Chute width :
30 m.
Bucca weir (Bucca QLD, Australia
1987) (H. CHANSON, 23 Dec. 2001). RCC irrigation weir
on
the Kolan river.
Neil Turner weir (Mitchell QLD, Australia 1984). 5.9
m
high stepped weir on the Maranoa river. Photo
No.
1 : general view in July 2001 (Courtesy of Chris PROCTOR). Photo
No.
2 : detail of steps in July 2001 (Courtesy of Chris PROCTOR).
Artifical stepped cascade at Biloela (QLD, Australia).
Design flow: 390 m3/s, step height: 2 m, width: 100 m. Photo
No.
1 : General view shortly after construction in 2002 (Courtesy
of
Dr John MACINTOSH). Photo No. 2 :
View
of a step arrangement, from the right bank (Courtesy of Dr John
MACINTOSH).
Photo
No. 3 : 1:16 scale model, based upon a Froude similitude
(Courtesy
of Dr John MACINTOSH). Photo No. 4
: physical model in operation for Q = 10 L/s (20 m3/s prototype); all
the
water flows as seepage; the colours are paint sprayed on the rockfill
to
visualise erosion and scour. Photo No.
5 : physical model in operation for Q = 103 L/s (210 m3/s
prototype);
note overflows and seepage, and the hydraulic jump downstream of the
plunge
point.
Hinze
dam spillway (Stage 3). Operation on 29/1/2013 at 12:15, Q
~
170 m3/s. Photo No. 1:
View from downstream of the stepped spillway operation. Photo No. 2: View
from upstream of the uncontrolled ogee and stepped chute operation. See
also: "Interactions between a Developing Boundary Layer
and the
Free-Surface on a Stepped Spillway: Hinze Dam Spillway Operation in
January 2013",
Proc. 8th International Conference on
Multiphase Flow ICMF 2013, Jeju, Korea, 26-31 May, Gallery
Session
ICMF2013-005 (Video duration: 2:15). (Description)
(Record
at
UQeSpace) (Video
movie
at UQeSpace). Site visit with CIVL4120
Advanced hydraulics students on 24 October
2014: Photo No.11:
general
view of stepped spillway and stilling basin. Photo
No. 12: stilling basin and
turning veins leading to an ogee weir. Photo
No. 13: stepped spillway with
3.3 m high baffle blocks in the foreground. Photo
No. 14: details of baffle
block. Photo No. 15:
engineering students discussing about the spillway system next to a
baffle block. Photo
No. 16: CIVL4120 students with Professor Chanson at the spillway
toe. Photo No. 17:
stepped spillway toe and stilling basin. Small overflow on 3 May 2015: Photo No. 18: View
from downstream; Photo
No. 19: View from upstream, with flow direction from top to bottom.
Paradise
dam,
Biggeden QLD (Australia) - RCC gravity dam equipped with an
uncontrolled stepped spillway. Photo
No. 1: General view of the
spillway on 5 March 2013. Photo
No. 2: View of the spillway
and stilling basin operation on 5 March 2013. Photo
No. 3: Details of the
free-surface next to the inception of free-surface aeration on the
stepped spillway on 5 March 2013. Photo
No. 4: turbulence and air-water flow in the stilling basin on 5
March 2013.
Stepped storm waterway systems
Storm waterway at Miya-jima (Japan) - Photo
No.
1 : storm waterway below below Senjò-kaku wooden hall on
19 Nov. 2001. The stepped chute is steep (slope > 45 deg., h ~ 0.4
m).
The Senjò-kaku wooden hall was built by Kyomori (AD 1168) and
left
unfinished at his death. It is likely that the waterway design dates
from
the 12th century.
Stepped road gutter systems : another
application
of the stepped chute design. Photo No.
1 : steep gutter along the Western freeway, Brisbane (Photograph
taken
in Dec. 1999). Photo No. 2 :
double
road gutter looking downstream, next to Sumner Rd freeway entrance,
between
Darra and Mt Ommaney, Brisbane (Photogaph taken in Nov. 1996).
Research onto stepped spillway hydraulics
Research on stepped spillways at UQ : 22º slope, h = 0.10
m, l = 0.25 m, W = 1 m, q = 0.103 m2/s, dc/h = 1.0. Photo
No.
1 : View from upstream looking towards the inception point of
air
entrainment. Photo No. 2: Side view
(Y90
= 0.078 m, Cmean = 0.48, Fmax = 149 Hz at the probe location)
(Photographs
taken on 7 July 2000). Photo No. 3
: dc/h = 1.5 (flow from left to right, run Q23). Photo
No.
4 : dc/h = 1.1 (run Q21). Photo
No.
5 : dc/h = 0.7 (run Q22). (Download
the
full results as PDF files : Part 1
and Part 2)
Research on stepped spillways at UQ : 16º slope, h = 0.10
m, l = 0.35 m, W = 1 m. Photo
No.
1 : Nappe flow (without hydraulic jump NA3) for dc/h = 0.64.
{http://www.uq.edu.au/~e2hchans/photo.html#Step_spillways} | Photographs of stepped spillways |
{http://www.uq.edu.au/~e2hchans/self_aer.html} | Self-aeration in chutes and spillways |
{http://www.uq.edu.au/~e2hchans/over_st.html} | Embankment overflow stepped spillways & earth dam spillways with precast concrete blocks |
{http://www.uq.edu.au/~e2hchans/reprints/book4.htm} | Hydraulics of stepped chutes and spillways |
Hubert
CHANSON is a Professor in Civil Engineering, Hydraulic Engineering
and Environmental Fluid Mechanics at the University
of Queensland, Australia. His research interests include design of
hydraulic structures, experimental investigations of two-phase flows,
applied hydrodynamics, hydraulic engineering, water quality modelling,
environmental fluid mechanics, estuarine processes and natural resources.
He has been an active consultant for both governmental agencies and
private organisations. His publication record includes over 800
international refereed papers and his work was cited over 3,700 times
(WoS) to 13,500 times (Google
Scholar) since 1990. His h-index is 32 (WoS), 34 (Scopus) and 55 (Google
Scholar), and he is ranked among the 150 most cited researchers in
civil engineering in Shanghai’s
Global Ranking of Academics. Hubert Chanson is the author of twenty
books, including "Hydraulic Design
of Stepped Cascades, Channels, Weirs and Spillways" (Pergamon,
1995), "Air Bubble Entrainment in
Free-Surface Turbulent Shear Flows" (Academic
Press, 1997), "The Hydraulics
of Open Channel Flow : An Introduction" (Butterworth-Heinemann,
1st edition 1999, 2nd
editon 2004), "The Hydraulics of
Stepped Chutes and Spillways" (Balkema,
2001), "Environmental
Hydraulics of Open Channel Flows" (Butterworth-Heinemann,
2004), "Tidal
Bores, Aegir, Eagre, Mascaret, Pororoca: Theory And Observations" (World
Scientific, 2011) and "Applied
Hydrodynamics:
an Introduction" (CRC
Press, 2014). He co-authored two further books "Fluid Mechanics for
Ecologists" (IPC Press, 2002) and "Fluid Mechanics for Ecologists.
Student Edition" (IPC, 2006). His
textbook "The Hydraulics of Open Channel Flows : An Introduction" has
already been translated into Spanish (McGraw-Hill
Interamericana) and Chinese (Hydrology Bureau of Yellow
River Conservancy Committee), and the second
edition was published in 2004. In 2003, the IAHR
presented him with the 13th Arthur Ippen Award
for outstanding achievements in hydraulic engineering. The American
Society of Civil Engineers, Environmental and Water Resources Institute
(ASCE-EWRI) presented him with the 2004 award for the Best Practice paper
in the Journal of Irrigation and Drainage Engineering ("Energy
Dissipation
and Air Entrainment in Stepped Storm Waterway" by Chanson and
Toombes 2002). Hubert Chanson edited further several books, including the
recent monograph "Energy
Dissipation
in Hydraulic Structures" (Chanson 2015, IAHR
Monograph, CRC Press). He chaired the Organisation of the 34th
IAHR World Congress held in Brisbane, Australia between 26 June and
1 July 2011. He chaired the Scientific Committee of the 5th IAHR
International Symposium on Hydraulic Structures held in Brisbane in
June 2014. He chairs the Organisation of the 22nd Australasian Fluid
Mechanics Conference in Brisbane, Australia on 6-10 December 2020.
His Internet home page is http://www.uq.edu.au/~e2hchans.
He also developed a gallery of photographs website {http://www.uq.edu.au/~e2hchans/photo.html}
that received more than 2,000 hits per month since inception.
More pictures of stepped spillways are
here
...
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