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HYDROLOGICAL SERVICES

Performance

Water Resources Assessment

Flood Warning Service

Hydrometeorological Advice

OBJECTIVE

To provide an effective national source of hydrological and hydrometeorological data and advice and to meet the needs of the general public, emergency services and other specialised users for effective, reliable flood warning services.

OUTPUT

Publications, reports and data sets on Australia's surface water resources and their utilisation and on the links between weather, climate and surface water; along with a comprehensive national flood warning service for coastal and inland rivers provided, according to local arrangements, in collaboration with relevant state and local government agencies; and advice to public and private sector organisations on the use of hydrometeorological information in design, construction and other applications.

OUTCOME

Enhanced community safety and well-being through the effective use of hydrological and related services by the general public and other major social and economic sectors.

Hydrological Services include water resources assessment, the provision of flood forecasting and warning services and hydrological and hydrometeorological advice for design. These services depend heavily on the information collected through the Bureau's basic national meteorological observation networks. The Flood Warning Service also operates a special purpose network of rainfall and river level stations in cooperation with State and Local Government agencies.

Hydrology Sections, incorporating Flood Warning Centres, exist in all Regional Offices of the Bureau. Overall coordination is provided by the Head Office Hydrology Unit, which also provides some services. Regional service delivery depends on close cooperation with State and Territory water and emergency service authorities and Local Government agencies.

Resource Use

The resources committed to Hydrological Services in 2000-01 are summarised in Table 3 and are given in more detail in Table 13.

Table 13. Hydrological Services expenses and revenue ($'000) and staff level for 2000-01 together with the actuals for1999-2000 and the 2000-01 Budget and Budget plus Additional Estimates appropriations.

	ACTUAL EXPENSES 1999-2000	BUDGET 2000-01	BUDGET & ADD. EST. 2000-01	ACTUAL EXPENSES & REVENUE 2000-01
	($'000)	($'000)	($'000)	($'000)
FINANCIAL
EXPENSES
Employee Expenses (Appropriation)	3,900	3,756	3,737	3,812
Employee Expenses (Section 31)	208	181	181	193
Supply of Goods and Services (Appropriation)	965	658	843	1,246
Supply of Goods and Services (Section 31)	183	-6	-10	187
Operating Leases Rentals	484	482	479	517
Depreciation	367	409	403	369
Other Goods and Services Expenses	0	0	0	0
(WMO Contribution)	0	0	0	0
Capital Use Charge	23	57	61	0*
TOTAL PRICE OF OUTPUT	6,129	5,537	5,694	6,324
REVENUE
Appropriation	5,544	5,362	5,521	5,521
Sale of Goods and Services	402	175	171	171
Miscellaneous - other	2	0	2	2
TOTAL REVENUE	5,948	5,537	5,694	5,694
STAFFING
Staff Years (actual)
- Funded from Employee Expenses (Appropriation)	55.0	54.9	54.6	52.7
- Funded from Supplier Expenses (Appropriation)	0.2	0.2	0.2	0.5
- Funded from Section 31 Receipts	3.9	3.9	3.9	3.8
- Funded from Capitalised Salaries (Asset Replacement)	2.4	6.0	6.0	6.2
TOTAL STAFFING	61.5	65.0	64.7	63.2

* In 2000-01, Capital Use Charge was not accounted as an expense.

Performance

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Performance during 2000-01 was assessed at two levels in terms of the:

· quality, quantity and price of the outputs directed to the achievement of the planned outcome relative to the agreed target levels; and

· contribution of the outputs to the achievement of the planned outcome.

The measures used as a basis for performance assessment were as published in the Portfolio Budget Statements 2000-01 for the Environment and Heritage Portfolio (Budget Related Paper No. 1.7). The performance for 2000-01 against each of the performance measures and targets for quality, quantity and price of outputs is summarised in Appendix 11.

The key strategies used to enhance the Bureau's hydrological services and contribute to the achievement of the planned outcome during 2000-01 included identification of the services required to meet the needs of various user groups, through consultation or membership of formal representative bodies, such as the:

· Australian National Committee on Large Dams (ANCOLD);

· State/Territory Flood Warning Consultative Committees;

· State/Territory emergency service organisations;

· State/Territory water authorities;

· Agriculture and Resource Management Council of Australia and New Zealand (ARMCANZ);

· Cooperative Research Centre for Catchment Hydrology (CRCCH);

· National Committee on Water Engineering of the Institution of Engineers, Australia;

· Commonwealth Department of Agriculture, Fisheries and Forestry;

· Commonwealth Department of the Environment and Heritage;

· National Land and Water Resources Audit;

· Standards Association of Australia;

· Commission for Hydrology of the World Meteorological Organization (WMO); and

· Intergovernmental Council for the International Hydrological Programme (IHP) of UNESCO.

A notable achievement during the year was the election of Mr Bruce Stewart, Superintendent Hydrology, to the position of vice-president of the WMO Commission for Hydrology.

The contribution to achievement of the planned outcome during 2000-01, assessed in terms of the indicators listed in Appendix 12, is reviewed below for each of the individual outputs (Water Resources Assessment, Flood Warning Service and Hydrometeorological Advice), drawing on the performance information summarised in Appendix 11.

Water Resources Assessment

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Water Resources Assessment in the Bureau contributes to the assessment and management of Australia's water resources through coordination of the Bureau's input to water resources issues and projects. This includes the assessment, design and development of data collection networks, development of information systems, development of water management decision support tools and monitoring climate variability and climate change issues that may impact on future water resource availability. Water Resources Assessment also acts as a focus for Australian input to, and dissemination of information from, the international hydrology and water resources programs of the World Meteorological Organization and UNESCO.

The project to develop a national data bank of stochastic climate and streamflow models, being undertaken within the CRCCH Climate Variability program, made up a significant part of the work program throughout the year. A major literature review and report of recent Australian and overseas research on point and multi-site stochastic climate models was completed and published. Initial testing of annual rainfall models selected following the literature review, using data for 40 sites across Australia, was completed and a report prepared for publication. The testing has shown that a first order Markov model is adequate for generation of rainfall data in Australia. The daily rainfall models selected from the literature review are currently undergoing testing and further development using data from 20 sites across Australia. A workshop that explored the use of stochastically generated data in assessing the risk of water supply systems was hosted by the Bureau in February. The workshop included participants from water agencies in eastern Australia and was successful in raising the level of understanding of the generation and use of stochastic data to assess risk.

The collaborative project between the Bureau and the CRCCH to prepare national evapotranspiration maps was completed and the maps were published in June. In addition to the printed map set that forms part of the new edition of the Climatic Atlas of Australia, the evapotranspiration data are being made available in digital form as gridded data sets on a CD-ROM.

The RAINMAN Streamflow- Runoff Project moved into its final phase during the year, with the next version of the RAINMAN (rainfall management) decision support tool expected to be released during 2001-02. This project is being undertaken by the Queensland Department of Primary Industries in collaboration with the Bureau of Meteorology, the University of Melbourne and the Queensland Department of Natural Resources, with funding from the Land and Water Resources Research and Development Corporation (LWRRDC), with the objective of upgrading the RAINMAN decision support tool to include a seasonal streamflow analysis capability and a data base of streamflow data. During the year, the Bureau processed additional observed streamflow data obtained from a number of water agencies to bring up-to-date the data set previously assembled for this project. In addition, time series of modelled data for 83 sites were also obtained from the New South Wales Department of Land and Water Conservation, to complement the modelled series prepared by the University of Melbourne for other parts of the country.

The problem of corrosion of the bucket support mechanism in tipping bucket rain gauges (TBRGs) used by the Bureau to measure rainfall intensity, was eliminated with the replacement of the last affected gauges during the year. The replacement of the corroded gauges took considerably longer than expected owing to difficulties in identifying a solution to the problem and then in securing a supply of replacement gauges that met the required accuracy standards. A tendering process to establish a supply contract for the provision of TBRGs that meet the Bureau's specification was completed. Unfortunately, the two makes of equipment tendered failed to consistently meet the calibration standards set down in the specification. Consequently, the replacement of the remaining chart recorders in the rainfall intensity network was not able to proceed. A reassessment of the equipment specification was commenced, drawing on information received from other National Meteorological Services and the recommendations of the World Meteorological Organization . It is expected that a new tendering process will be undertaken during 2001-02, following this review.

Stream Gauging Information, Australia, the national catalogue of river level stations operated by the State and Territory water agencies and the Bureau, was released as a Web-based searchable data base in January. Efforts were made to provide a more complete picture of the national river network by including the details of river stations operated by the smaller regional, and major urban, water agencies. The Web data base will be updated progressively as these station details become available.

The institutional arrangements to enable the ongoing updating of Australian Water Resources Assessment 2000 (AWRA2000) data bases and products continued to evolve. As part of its coordinating and facilitating role proposed under these arrangements, the Bureau hosted a AWRA2000 Technical Review Workshop during June. The workshop was attended by 30 representatives from 15 stakeholder organisations. The workshop reviewed the strengths, weaknesses, opportunities and threats in relation to AWRA2000, identified activities required to deliver an ongoing capacity to report on the status of Australian water resources and discussed the institutional arrangements required.

Activities undertaken to fulfil the national and international components of Water Resources Assessment during the year included coordination and administration of Bureau participation in ARMCANZ and national representation on the WMO Commission for Hydrology and the UNESCO Intergovernmental Council for the International Hydrological Programme.

National activities aimed at ensuring that projects undertaken and priorities identified meet the needs of the Australian water industry included:

· membership of the Australian National Commission for UNESCO Science Network and of various ARMCANZ Committees and Working Groups; and

· input to ARMCANZ documents, such as the National Water Quality Management Strategy and the High Level Steering Group on Water, emphasising, in particular, the importance of climate influences on water resource issues and national water resources assessment issues.

Input was provided by the Bureau to international projects, and dissemination of information from Australia was promoted at an international level, through:

· provision of Australian representation at the meeting of the UNESCO International Hydrological Programme Regional Steering Committee for South-East Asia and the Pacific, in Christchurch, New Zealand in November;

· provision of Australian representation at the Eleventh Session of the WMO Commission for Hydrology, in Abuja, Nigeria, in November. Mr Bruce Stewart, Superintendent Hydrology, was elected as vice-president of the Commission for Hydrology at this session;

· participation in the UNESCO-sponsored Asian Pacific FRIEND (Flow Regimes from International, Experimental and Network Data) Project and its associated scientific program, maintaining the Australian Node for the Internet based Asian Pacific FRIEND Water Archive for the provision of data to researchers in the region and sourcing data from countries in the region for inclusion in the water archive;

· management of the WMO Hydrological Operational Multipurpose System (HOMS) National Reference Centre for Australia;

· membership of the WMO Region V (South-West Pacific) Working Group on Hydrology;

· membership of the WMO Commission for Hydrology Advisory Working Group;

· chairing the WMO Commission for Hydrology Working Group on Basic Systems; and

· participation in a review of the Ontario (Canada) Hydrometrics by Performance Management Network Inc., Canada.

Flood Warning Service

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The Bureau of Meteorology flood warning service contributes to enhanced community safety and well-being through the provision of effective and efficient flood warning services, in close cooperation with State and Local Government agencies.

Users of flood warning services include emergency management agencies and members of the public, particularly those in flood prone areas. The Bureau disseminates flood warnings and information to the public (via the media, Internet and fax) as well as direct to flood response agencies for more detailed interpretation and dissemination. The Bureau operates one essential part of what is referred to as the `total flood warning service'.

User satisfaction with the functioning of the Flood Warning Service was gauged through the following activities:

· Debriefings - feedback from flood-affected communities during formal debriefings with other agencies involved in the `total flood warning service'. Considerable positive feedback was received at these debriefings along with suggestions for improvements and extensions to the service;

· Flood Warning Consultative Committees - feedback from agencies involved in the `total flood warning service' through the Flood Warning Consultative Committee (FWCC) in each State/Territory. The FWCC is responsible for setting the priorities for development of the flood warning service and comprises representatives from these agencies;

· Reports - formal assessments of service performance following some major flood events. These reports are usually only commissioned following major flooding events where problems were experienced. The reports usually investigate and make recommendations for the `total flood warning service'. Often the investigation leading to the report includes surveys of users. The reports are objective, being carried out by organisations external to the Bureau, but often are commissioned or jointly sponsored by the Bureau;

· Formal Reviews - feedback provided through formal reviews of components of the Bureau's Hydrological Services;

· Conferences, workshops and meetings - ongoing feedback from users at conferences, workshops and meetings; and

· Systematic user surveys - this approach was introduced for the first time this year and is planned to be used more extensively in future years.

Feedback on the Bureau's flood warning services gathered through the above activities revealed a high level of satisfaction with services in general during 2000-01. Specific criticisms of the services provided during the major flooding in New South Wales were followed up through public meetings and direct consultation with affected parties to resolve the areas of concern.

The first major flood of the year occurred during July along the North Esk River, particularly at Corra Linn, following heavy rainfall across the northern part of Tasmania. Strathbridge was flooded when the Meander River reached a major flood peak and Deloraine, also on the Meander River, experienced moderate flooding. This flooding also cut many roads and involved occasions of flash flooding in several areas in the north of the State. The same areas of Tasmania were flooded again in October when heavy rainfall led to significant, but less serious, flooding along the Meander River, again at Strathbridge and Deloraine. This period of heavy rainfall also led to minor flooding in the upper reaches of the South Esk River at Fingal. The only other flooding during October was in Victoria, where heavy rainfall caused flooding of roads and some flash flooding in the Melbourne metropolitan area.

In November, widespread rainfall occurred in many parts of Queensland. The worst flooding was along the Warrego River with moderate flooding in the upper reaches around Charleville increasing to major flooding in areas downstream to the New South Wales border. The Macintyre River, along the New South Wales-Queensland border, flooded several towns and properties, including Goondiwindi which experienced major flooding. Further downstream, Mungindi suffered moderate flooding later in the month. The only other major flooding for the month occurred along a number of the inland rivers, including the Bulloo River around Quilpie, and the Thompson and Barcoo Rivers and Cooper Creek with moderate to major flooding around Windorah extending to the Christmas period. Other Queensland rivers to experience flooding during November included the Condamine-Balonne Rivers, the Fitzroy River (several areas) following very intense rainfall along the coast between Mackay and Rockhampton, and the Paroo River. Further south in New South Wales, major flooding was reported during November in the Namoi, Macintyre, Macquarie and Gwydir Rivers, and moderate to major flooding occurred in the Darling River. The heavy rainfall also extended across the Warrego, Bogan, Lachlan, Castlereagh and Paroo Rivers in western inland New South Wales and the Hunter River near Newcastle, flooding many communities and agricultural areas to minor to moderate levels. In Tasmania, moderate flooding was reported in the upper and middle reaches of the South Esk River, particularly around Fingal and Llewellyn. The only significant flooding in Australia during the month of December was in Queensland where rain falling on catchments already wet from the previous month's rainfall led to fairly widespread flooding. This began with tropical cyclone Sam which caused flooding in six river basins along the north tropical coast, in particular the coastal catchment of the Don River. In addition many inland rivers were flooded during the month including the Paroo and Bulloo Rivers, Thomson and Barcoo Rivers and Cooper Creek, the Diamantina and Georgina Rivers. In the gulf region, the Nicholson, Gregory, Albert, Leichardt, Flinders and Cloncurry Rivers also flooded, with flooding extending right through to the end of the month in some cases.

The most significant river flooding during the year occurred in northern New South Wales during February and March. Heavy rainfall in early February led to major flooding in the town of Lismore on the Wilson River and, a month later, the towns of Grafton and Kempsey experienced extensive flooding following heavy rainfall over a period of several days. In Grafton, the high risk that the levee could have overtopped led to the evacuation of several thousand people. Less serious flooding occurred in surrounding areas during both of these events.

Photo Heavy rainfall in March lead to the highest flooding since 1954 in and around Grafton, New South Wales, including the small town of Ulmarra (above). (Courtesy of the Northern Daily Examiner)

The flood warning service covered communities in all States and the Northern Territory and included flooding in small creeks as well as in the longer slow flowing inland river systems. The warning products included early alerts to the possibility of flooding, site-specific forecasts of river height and the expected impact in terms of minor, moderate or major flooding in specific river basins, and more generalised products issued on a regional basis. During 2000-01, 2088 flood warning messages were issued, which is greater than the average for the last decade. A near record number of warnings was issued in New South Wales.

The number of flood warning products issued, particularly through the Bureau's web site, increased again in 2000-01. This service attracted positive feedback from a wide range of users during flood periods as well as from other groups of users such as canoeists and other recreational users of inland waterways. The total number of accesses to automated hydrological service delivery systems was some 660,000 during 2000-01, of which around 10,000 were accesses to facsimile systems and 650,000 were accesses to products on the Bureau's web site. The number of hydrological data, information and flood advisory services issued this year was around 400,000 against a `target' of 150,000.

The growth in products issued this year was attributable primarily to the extension of automatically generated summaries of rainfall and river height data from two States (Queensland and Victoria) to all States and the Northern Territory. These products were posted on the Bureau's web site and updated on an hourly basis. A new service introduced toward the end of the year was the real-time map display of rainfall and river level information. Initially developed in Queensland, dissemination of these maps on the Bureau web site was extended to all States and the Northern Territory. The setting of performance targets in this area will remain problematical owing to the dominant impact of weather conditions on the need for services and the volume of services provided.

New and improved technical systems were introduced during the year to improve the efficiency of the service and to extend its coverage to new areas. In Victoria, new data collection networks were installed on the lower Goulburn River and upgraded equipment was installed at several stations in the Tasmanian flood warning network to improve the reliability of the system. A number of projects was commenced in Queensland, funded through the Regional Flood Mitigation Programme, including systems to improve flood warning for the Burdekin, Houghton, Tully and Murray Rivers. The flood warning data collection system in New South Wales was strengthened during the year by the introduction of new equipment to upgrade some sites and improve network densities, and a preliminary flash flood warning system was developed for the lower Cooks River. In the Northern Territory, the Bureau provided support to the improvement of the warning system for the Waterhouse and Roper Rivers. In Western Australia and South Australia, the emphasis during the year was on consolidating the existing networks by repair and replacement of faulty equipment, with only a small number of new sites being installed.

The major focus for technical improvements continued to be the development of hydrological applications for the Australian Integrated Forecast System. The range of products generated through this system increased, in particular with an increased range of Web-based products. The hydrological modelling system was further enhanced and is now fully implemented in Queensland and partially implemented in Victoria. The local agency data collection software (ENVIROMON) was further developed and new versions released to Regional Offices and local agencies. A new software system to manage the polled telephone telemetry component of the data collection network was trialed during the year.

Flood Warning Consultative Committees (or their equivalent) continued to be a major forum for interacting with service users and ensuring services meet user needs and priorities. A growing emphasis on risk management focussed attention on warning systems and the demands for new and improved warning services continued to grow, stimulated particularly through the Regional Flood Mitigation Programme of the Department of Transport and Regional Services in some States. In Western Australia, a new Floodplain Management Council was formed, with improvements to the flood warning system being an important part of its terms of reference.

Involvement in the research activities of the Cooperative Research Centre for Catchment Hydrology continued this year, with a particular highlight being the development of a new tool for the short term forecasting of rainfall, especially suited to flash flood warning. This tool (known as SPROG, for Spectral PROGnosis) was trialed as part of the World Weather Research Programme evaluation of nowcasting tools undertaken in September (covering the Sydney Olympics). It showed comparable, if not better, performance than the more established tools used overseas. An example of the output from SPROG is shown in Figure 55.

Figure 55. Sample output from the Spectral Prognosis (SPROG) system, which provides guidance for the short-term forecasting of rainfall, particularly in flash flooding events, and which was trialed as part of the World Weather Research Programme evaluation of nowcasting tools, in Sydney from September to October.

Hydrometeorological Advice

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The Hydrometeorological Advisory Service contributes to enhanced community safety and well-being through the provision of specialised hydrometeorological advice and products to the scientific and engineering communities for the safe design of a wide range of hydrological and other civil infrastructure. In particular, government and community planning for secure water supply, and the safety of the infrastructure that supports it, relies on credible advice about the long-term variability of rainfall. The development of robust techniques for the analysis of this element and the provision of pertinent hydrometeorological advice to planners was a major component of the Bureau's hydrometeorological services again this year. Ongoing liaison and collaboration with State water agencies ensured the relevance of the developments and increased the likelihood that optimum use was made of the advice provided.

Hydrometeorological advice and products include estimates of Probable Maximum Precipitation (PMP), design Intensity-Frequency-Duration (IFD) rainfall information and a range of other statistical rainfall analyses, provided on an incremental cost recovery basis.

Probable Maximum Precipitation estimates are currently provided using one of four estimation methods:

· the Generalised Short Duration Method (GSDM), for short durations and small areas, published as Bureau of Meteorology Bulletin 53;

· the Generalised Tropical Storm Method (GTSM), for long durations in regions where tropical storms are of importance;

· the Generalised Southeast Australia Method (GSAM), for long durations in regions not affected by tropical storms; and

· a limited transposition method for the west coast of Tasmania, for long durations, based on a set of extreme storms specific to the region.

The Tasmanian west coast method is a new method which was applied to four catchments last year. A description of the development of this method was published as Report Number 7 in the Hydrological Report Series: Development of the method of storm transposition and maximisation for the west coast of Tasmania; an electronic version of this report was made available on the Bureau web site.

The main source of design rainfall information for hydrological studies in Australia continues to be the Bureau's rainfall IFD data as published in the 1987 edition of Australian Rainfall and Runoff (ARR). There was also demand for more specialised rainfall intensity information and analyses, which are being used as input to a wide range of design flood models and environmental studies including:

· the design and risk assessment of dams, bridges and drainage systems;

· the design of buildings;

· soil conservation studies; and

· the design of, and formulation of operational procedures for, satellite telecommunications links and mobile-phone networks.

Demand for IFD studies remained high during 2000-01, with 320 Computerised Design IFD Rainfall System (CDIRS) products requested and provided.

Revision of the GTSM continued during the year. The Generalised Tropical Storm Method Revision (GTSM-R) is now into its third year and continued to be a major component of the Hydrometeorological Advisory Service (HAS) activities. The project continued to receive significant financial sponsorship from major water authorities in Western Australia, New South Wales and Queensland.

A database of approximately 120 of the largest tropical storms in the rainfall record has been constructed and isohyetal analyses for each of the storms have been prepared. The site-specific components of each of the storms, such as moisture availability and topographic influences, are then accounted for in order to identify the most efficient storms over a range of areas and durations. This technique affords a larger sample of storms than would otherwise be possible with the existing 100 years of rainfall data. The result is a better estimate for the largest depth of precipitation that could realistically fall in the region of Australia where tropical storms are the source of the most significant rainfall.

A thorough understanding of the meteorological influences that give rise to extreme rainfall events within the region is necessary in order to delineate meteorologically homogeneous zones across which storms can be transposed. Figure 56 shows the region of applicability of the Generalised Southeast Australia Method (GSAM), the GTSM region, and the location of the storms studied. Storms which occurred in the GSAM region but which are meteorologically similar to those occurring in the GTSM region are also included in the GTSM-R storm database. The storms were grouped into four broad categories which describe the meteorological situation that gave rise to the extreme rainfall. The tropical cyclone related events are confined to a band around the coast and inland events tend to be dominated by monsoonal activity.

Figure 56. Regions of applicability of the Generalised Southeast Australia Method (GSAM) and the Generalised Tropical Storm Method Revision (GTSM-R), together with the locations and categories of the storms studied.

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