POKOLBIN PIPELINE PROJECT
Hunter Wine Country Private Irrigation District
The Board of
Management of the Hunter Wine Country Private Irrigation District (PID) is
pleased to have an opportunity to submit an entry for the 2001 Engineering
Excellence and Showcase Awards. (Photo above BoM & Project Manager with the
NSW Premier)
This
project’s greatest achievement other than its innovative engineering and
sophisticated control system is that as a true Community Project, owned and
operated by the community, it has demonstrated that a determined effort can
produce a valuable outcome in social, economic and employment terms by utilizing
the strength of goodwill to benefit the community.
Background
In early
1998 the Hunter Valley Vineyard Association (HVVA) formed a sub-committee to
establish whether an irrigation scheme in the Pokolbin area would be feasible.
The basis
for this was that a private pipeline existed from the Hunter River to a large
vineyard on Hermitage Road, Pokolbin. This pipeline had been successfully
operated for 20 years and was the only externally sourced irrigation in the
area. All other irrigation was from on site storage of run-off rainwater.
Further large scale development was unlikely without irrigation.
A reliable
permanent irrigation source was desirable not to increase yields, which has the
risk of lowering quality but to provide a level of insurance in drought periods.
Irrigation was not widely used in the area due to the uncertainty of water
supply.
Six
contributors donated $10,000 each for an initial feasibility study to be
undertaken by Kinhills. This report indicated that if the scale of the project
covered the vineyard area north to south between the New England Highway and
Mount View area and east to west from the Singleton Military Reserve to the
Lovedale area and if the level of participation was in excess of 80% the project
was potentially viable.
Establishment
The Lower
Hunter Water Users Association (LHWUA) was established with the assistance of
the NSW Department of Regional Affairs – Hunter Economic Development
Corporation (HEDC).
Members of
HVVA and other interested landholders were invited to join the Association and
the Kinhills report was presented to a public meeting. Over 150 persons joined
the LHWUA and each subscribed $90 per megalitre of water that they nominated
they would require per year. Some $400,000 was raised and this was administered
by HEDC to finalise engineering studies, obtain a water source and agreement for
the issue of water licenses. A management Committee of 12 persons was appointed
from the membership. The Committee met weekly to advance the project.
This and
later stages required and received the active co-operation and goodwill of both
State and Federal government and two local government authorities, Cessnock City
and Singleton Shire. The NSW State Government delegated the regional head of the
Premier’s Department to facilitate the project, and he and an HEDC
administrator attended the association’s management and planning meetings.
Water
License
The Department.
of Infrastructure & Natural
Resources (DIPNR) approved the granting of a
5-year low security Group Water License to the PID for a fee of $1,300,000.
There is an additional fee for water taken on a consumption basis.
Legislation
As a
community based project many issues arose such as ownership, liability and
security of funding. Many options regarding the structure of the entity were
explored, all of which had drawbacks.
Our legal
advisers then explored the option of setting up under the NSW Private Irrigation Districts Act 1973 which it
transpired gave all the rights and responsibilities we required and addressed
adequately the issues above.
The Act had
been used in other areas to establish small irrigation schemes of up to 20
irrigators; we planned at this stage to have up to 400 irrigators. The State
Government indicated willingness for the establishment of the Hunter Wine
Country Private Irrigation District as a statutory authority under the act. A
PID consists of lands that are proclaimed forming a PID, real persons or
corporations are not members. This provides a continuum not affected by change
in ownership of properties and consequently guarantees continuing income.
The PID is
constituted by Petition from participant landholders to the Ministerial
Corporation. The, then 320, LHWUA members petitioned and the Governor proclaimed
the Hunter Wine Country Provisional PID on 14th July 1999 and the
LHWUA was wound up. The PID changed from Provisional to a full PID when the
Group Water License was taken up and by that time the membership had risen to
384 representing 96% of the overall potential membership in the area.
The PID
levies an annual Rate or Charge on constituents to cover infrastructure,
maintenance, operating and other costs. Water usage is charged on a consumption
basis, (see Operational Guidelines)
Funding
On the basis
of a PID rather than an association we were able to obtain project loan funding
from the Commonwealth Bank of Australia. A 20-year debenture for $8.2 million
was issued with collateral provided by the cash flow from the Annual Rate or
Charge, which are enforceable under the PID Act as Charges over the land of the
constituent member. The pipeline itself is not suitable collateral, as it has no
intrinsic value other than as infrastructure.
The PID also
sought Federal funding under the Hunter Regional Adjustment Fund established on
the closure of BHP and received a grant of $520,000 towards the cost of pumps.
Construction
& Commissioning
The PID
appointed a full time project manager to supervise all aspects of the project on
behalf of and reporting to the Board of Management.
Tenders were
called for Principal Contractors for the project. A contract agreement was
undertaken with Rellney Nominees Pty Ltd.
Construction
tenders were called and let to TKC Excavations Pty Ltd. with a 26-week
construction period nominated.
Pipe tenders
were called and let to Iplex Pipelines Pty Ltd.
Pump tenders
were called and let to Brian Clulow Pumps Pty Ltd.
SCADA/Telemetry
tenders were called and let to Micro Control Engineering Pty Ltd
Energy
Australia was engaged to provide 3-phase supply to pump stations and low voltage
supply to the distributed metering and control system.
Both
Cessnock and Singleton councils fast-tracked approvals for construction and
waived the requirement for easements.
Construction
commenced at the end of August 1999 and the project was delivering water in
February 2000 a construction period of 22 weeks (allowing for time lost through
inclement weather).
Some
illustrative photographs show clockwise from top left:-
●
Trenching, ● Pipe-laid, ● Booster pumps Hermitage Road, ●
Meter box, ID post and supply valve at users boundary, ● Contactors and
VFD Hermitage Road, ● Low voltage supply, telemetry box and aerial post,
● Jump Up Creek crossing
Social,
Economic and Employment benefit
The PID has
had a social impact beyond employment in that it has demonstrated that a
community-based project could be delivered on budget on time having traversed 3
levels of government, several utilities and commercial companies. It has been a
unifying factor in the area and has led to a second PID being created in Broke
Fordwich where an 80 km 240 member pipeline is currently under construction.
The direct
economic benefit is the security offered to the annual grape crop and also for
the establishment of additional vineyards, olive groves, golf courses and
visitor accommodation.
The
University of Newcastle undertook an Economic Impact Study on behalf of HEDC and
NSW Government, which established the overall potential for an additional 600
jobs (300 direct and 300 indirect) to be created long term with this water
supply. An immediate significant increase in employment has been seen within the
first 12 months of operation. The study also predicted an economic impact of
between $1,000 and $5,000 per hectare in production value. Additional investment
flowing from the project was estimated at $140,000,000 partially due to several
resort and golf course developments with individual landholders with access to
the
PID investing an average of $160,000.
Environmental
and Heritage Impact.
The Wonnarua
Tribal Council conducted aboriginal heritage studies and there was found to be
no negative impact from the PID.
An
Environmental Impact Statement was prepared and the only issues requiring
ongoing review was salinity and water table impact.
The PID
undertook to prepare a Strategic Irrigation Management Plan (SIMP) for DIPNR and
engaged the Sydney University - Department of Soil Science and Chemistry to
conduct appropriate studies leading to a SIMP.
Landholders
will be developing on-farm Irrigation Drainage and Management Plans (IDMP)
addressing their use of irrigation.
The PID
water delivery is not a demand system and the water is supplied to on-property
storage dams or tanks for use as required in the irrigation schedule.
The PID will
monitor any macro environmental effects on a continuing basis.
Facts a
The Pokolbin Pipeline consists of
130km of modified PVC pressure pipe. The
pipe size ranges from 450mm (18”) diameter down to 80mm (3”) diameter at the
extremities.
There are a total of 11 Pumping
stations with 38 pumps that are strategically placed throughout the pipe network
with a total pumping power of approximately 1300kW.
The pipeline supplies 384 properties
at present and delivers up to 5000 million litres of water from Whittingham
(Hunter River) into the Lower Hunter Valley.
The pipeline extents from Whittingham (north of New England Highway and
Golden Highway junction) to the intersection of Old North Road and Hermitage
Roads. The pipeline then fans into
an intricate pipe network that is bound by:
·
Hermitage
Road to the West
·
Lovedale
road to the East
·
Old North
(Sweetwater) and Talga Roads to the North
·
Mount View
Road to the South
The total area that is covered by the
pipeline is approximately 500km2 and around 150km2 of this is occupied and irrigated by
the members of the Private Irrigation District.
Each property has an identifiable
valve and meter that is monitored and controlled automatically and
instantaneously. From every outlet,
information on the flow of water is passed back to a central computer system via
radio telemetry. The same radio
telemetry system is also used to receive instructions on the opening and closing
of the electric control valve.
The electric control valves have been
individually engineered such that regardless of;
1.
The location
of the valve in the system
2.
The
conditions downstream of the valve;
the flow and the pressure will be
consistent for every user.
The flow into a property is maintained
at 25m3/hr, that is 25,000 litre per hour or
5,500 gallons per hour. The
pressure at the valve is regulated to 150kPa or 22psi.
The operation of the scheme has been
scheduled to uniformly distribute water throughout the area at any one time.
The full allocation of 5000ML can be
delivered in an 8-month period (August –April), which covers an average
irrigation season for vineyards in the Hunter Valley.
The instantaneous flow rate into the
Lower Hunter through this scheme is about 300 Lps or 1080 m3/hr (which is just
over 1 million litres per hour).
Although the scheme extracts water at
this rate from the Hunter River, the net impact downstream will be negligible.
Water required by the Pokolbin scheme, is ordered from the Department of
Infrastructure & Natural Resources operators at Glennies Dam. This requested quantity of water is released from the Dam in
addition to the quantity “regulated” from the dam at that time. Therefore,
there is no danger of lowering the “environmental flow” in the river.
The risk of this is totally eliminated
by the implementation of continuous level sensors at the pump site in the river.
The system will shut itself down, if there is a fall in the level of the
River.
The system also incorporates
continuous water quality monitoring. Characteristics
such as pH and EC (acidity and salinity) are to be constantly measured and
should either constituent fall outside that of an allowable range set from time
to time by the PID Board, pumping into the Pokolbin Pipeline will cease.
The central control system, not only
schedules, controls and monitors every property connection, but it also controls
and monitors all of the 11 Pump Stations. Key Pump Stations accurately control pump performance through
Variable Frequency Drives (VFD). The CITEC proprietary software control system
provides continuous full data records that are maintained locally and archived
in Perth for retrieval.
Sensors at strategic locations
throughout the pipe network continually monitor the system pressure.
Should any of these pressure-monitoring locations be low on pressure, the
VFD at the Pump Station is alerted and VFD then increases the electrical
frequency to the motor, thus increasing the speed of pump rotation and therefore
increasing the output pressure. This
continues until the system pressure at the critical field location is satisfied.
By implementing this system of pump control energy consumption is totally
optimised at all times.
The control system also records all of
the pressures and flows in the network, and is intelligent enough to identify if
there are any leaks in the system. It
is not only able to identify that there is a leak, but is able to identify the
approximate location of the leak. The
same applies if water is being “illegally” obtained from the pipeline.
In addition to all of this, the
Central Computer is capable of also automatically generating the invoices for
monthly water consumption, ready for mailing to clients.