Standing in constant rain while a crew applied a chainsaw to a 20 metre-high tree which blocked Sundew Crescent in O'Connor, Mr Graham said crews had been flat out since last Tuesday.

More than 900 calls for help had been received, more than 700 for leaking roofs. Increasingly, large trees were falling because saturated soil could no longer provide the friction necessary to support them. He was gratified no one had been hurt.

High-quality plastic, much less expensive and just as robust as tarpaulin, was now used to keep water out of leaking roofs. An advantage of this was that crews did not have to return to collect the plastic.

Major causes of leaking roofs were blocked gutters and downpipes, poorly maintained roofs and gutters which did not have the capacity to handle the volume of water.

ACT Emergency Service had about 200 volunteers and was recruiting another 25.

''As kind-hearted as the volunteers are, we also recognise their employers,'' Mr Graham said. They paid volunteers while they helped on occasions like this.

Their families too deserved thanks.

''It is a combination of the good will of everyone which allows us to get this done.'' No government in Australia could afford to pay for all of the volunteering work.

This included St John Ambulance and rural fire services.

''No government could ever afford to have full-time staff for that.''

Some people joined the ACT Emergency Service simply to help the community.

Others as a step to joining the permanent emergency services, such as police, fire and ambulance.

''Some do it to learn the skills we can offer and some do it to increase their circle of friends.''