Yass and Sutton State Emergency Service volunteers were called out to 20 jobs over 24 hours as a severe storm hit the Yass Valley on Saturday evening.

The Rural Fire Service was also kept busy attending 25 small grass fires in the zone which were lit by lightning strikes during the storm.

Four homes came under threat of flooding and five homes suffered roof damage.

Most of the homes threatened were in Merriman Drive, Yass, as water flowed thick and fast down the road. One home on Merryville Drive in Murrumbateman also came under threat.

The SES was also called to clear six trees, located on Yass River Road, Kaveneys Road, Scrubby Lane in Murrumbateman, the Barton Highway and at The Globe Inn in town.

With more than 70mm falling within an hour in some areas, SES operations officer Peter Chatwin urged residents to become storm ready by clearing their roof gutters.

“Most of the problems were that people didn’t have their gutters cleaned – most [callouts were] for overflowing gutters,” he said.

He said clear gutters helped to prevent flooding inside the house.

“It creates flooding inside the house – water builds up inside the gutter and can’t escape down the drain pipes … so it floods the inside of the house.”

He had received reports from residents on Yass River Road that it was “like a tornado went through”.

He said Scrubby Lane was also “trashed”.

He believed it to be close to the worst storm the organisation had seen for the Yass Area.

“Job-wise it came in fairly quickly. It’s not the worst, but it came close.”

The Bureau of Meterology issued a severe storm warning for a wide area of south eastern NSW on Saturday.

The warning came just three weeks after Yass residents were on high alert as a bushfire burnt out of control to within 10 kilometres of the township.

RFS operations manager Ian Kennerley said most of the small fires caused by lightening had been extinguished with rainfall. There had been seven still burning the following morning and another grass fire at Wee Jasper on Monday afternoon.

“To say we’ve had a busy time is an understatement.”

Mr Chatwin directed residents to keep up-to-date with storm activity via the Yass and Sutton SES Facebook and Twitter sites and visit www.stormsafe.com.au for guides on keeping safe and protecting your home during a storm.

Six members of the Yass SES were deployed to Sydney and the mid-north coast to help with storm clean up yesterday.