An emergency-level flood warning was issued on Thursday afternoon for the Goulburn River from Lake Eildon to Seymour north of Melbourne, with anyone in low-lying areas or close to a waterway warned they are in danger and should move to higher ground immediately.

The State Emergency Service has rescued 18 people including those driving through floodwaters in rural areas.

The SES has received more than 1000 calls for help in the past 48 hours, mainly in Swan Hill, Echuca and Seymour.

Echuca residents are advised to boil drinking water until further notice after stormwater entered a storage tank.

The rains caused landslides at Separation Creek on the Great Ocean Road on Thursday and at Falls Creek in the alpine region on Wednesday.

Severe weather warnings have been issued in most parts of the state with widespread moderate to major flooding expected.

There are 46 sandbag collection points across the state and it’s believed thousands have been distributed to residents so far.

At least 100mm of rain has already been recorded in the northern Goulburn-Broken catchment.

Watch and act alerts have been issued for major flooding of multiple river systems including the Campaspe in Central Victoria and Ovens and King rivers in northeast Victoria.

In the 24 hours to 8am on Thursday, 40mm to 80mm was recorded in the Campaspe catchment, with up to another 100mm forecast throughout the day.

The Thompson Dam in Gippsland could overflow by the weekend.

Other catchments which have not spilled in decades are flooded, including the Dartmouth and Lake Eildon dams.

Officials have been doorknocking along the Maribyrnong in inner Melbourne, while search and rescue teams are on standby.

Almost 10,000 homes were without power overnight and hundreds are yet to be restored, according to Powercor and the State Control Centre.

Sarah-Jane Gill, a manager at the Rochester Riverside Holiday Park in rural Victoria, has been evacuating guests and said she could see the river rising from her home.

“It is scary. You laugh in the face of it all but we’re very nervous,” she said.

Rochester cafe owner Lisa Froon feared water would seep through her premises but chose to remain open to provide food to locals.

“I had some tears last night,” she said.

Campaspe Shire Mayor Chrissy Weller said community safety was the priority and a relief centre is open in Echuca to support evacuated residents.

In 2011, a record flood hit the town of Rochester after the Campaspe River reached a historic peak of 9.12 metres.

Bendigo Mayor Andrea Metcalf has ordered parents to collect their children from council-run childcare centres by noon due to weather concerns.

She said the area was bracing for the impact of severe flooding in Rochester to flow downstream to Bendigo.

Multiple schools across the state, including Seymour College and Kilmore’s Assumption College, closed early and switched to remote learning due to weather concerns.

Regional transport has been impacted, with buses replacing V/Line trains between Albury and Seymour in both directions, due to extreme weather and flooding.

-AAP