Hunter Flooding on the Paterson & Williams

Paterson The Lower Hunter River in flood, Hunter River catchment area: 22 000 sq km and its major tributaries Mean annual runoff: 2 000 000 ml Hinton 1998 PATERSON Catchments contributing to runoff: are prone to flooding. (photo courtesy Goulburn River (15%), Upper Hunter (45%), Floods typically occur Maitland SES Paterson & Williams (40%) Lower Hunter catchment area: 380 sq km in the Paterson and Unit). Williams rivers in Rural flooding summer due to cyclonic

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a in Maitland t Seaham Weir e depressions moving

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s 1989 (photo o SEAHAM south off the Queensland n

courtesy CMA).

R coast. The area of the i ve r r e v Paterson and Williams i

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s catchments comprises

m a i l l only 11% of the total HINTON i W Hunter River catchment GREEN ROCKS MORPETH H u n area, and both streams te Rive MAITLAND r r

meet the main channel

RAYMOND well below Maitland TERRACE (Figure 1). Despite the relatively small catchment sizes, runoff

floodplain from these catchments contributes 40% of the total runoff to the Hunter HEXHAM River catchment.

Figure 1. Lower Hunter Catchment, from Maitland to Hexham

HUNTER COMMUNITY RECOVERY FUND Better FloodSafe than sorry

Floods have been recorded on the since 1929 and on the Williams River since 1950. On the Paterson, 26 major floods (greater than 12.2 m (AHD*) at Gostwyck Bridge) have been recorded. Figure 2 shows floods greater than 13.5 m (AHD). The highest flood on record peaked at 15.24 m (AHD) in March 1978. On the Williams River five major floods (greater than 8.50 m at Dungog gauge station) have been recorded (Figure 3).

1955 flood In the 1955 flood, the Williams and Paterson rivers contributed a massive amount of floodwater to the Hunter River, approximating 308 000 megalitres—enough to more than half-fill Harbour. Fortunately, the peak discharges from these two rivers occurred on 24 February, one day in advance of the main Hunter River flood. If the three rivers had reached their peaks on the same day, the impacts of the flooding would have been even worse. The rural areas from Maitland to were inundated. The water was 1.4 m deep in the Victoria Hotel at Hinton and 0.5 m deep in the Clare Castle Hotel at Raymond Terrace.

Recent floods Floods higher than the 1955 flood have continued to occur on the Williams and Paterson rivers, and often strike with little warning. The recent floods in 2007 are a timely reminder to prepare for floods—have a home emergency kit ready and know your evacuation route. Even minor floods Figure 2. Floods greater than 13.5 m (AHD) recorded on the Paterson can affect rural properties and cause flooding on roads and

River at Gostwyck Bridge since 1929. causeways. ➜ Rural properties at Morpeth flooded in 1998 (photo courtesy Maitland SES). Road cut off by floodwaters at Phoenix Park in 2001 ➜ (photo courtesy John Lane).

* Australian Height Datum (AHD)—a datum used to measure Figure 3. Floods greater than 8.5 m recorded on the Williams River at vertical height based on mean sea level as zero. Dungog Station since 1950. References NSW Public Works 1994, Lower Hunter Flood Mitigation Scheme Fact Sheets 1994-1, 1994-6 & 1995-1a.

For emergency help in floods, call the SES on 132 500 www.ses.nsw.gov.au