What the river changes
Flood country
The NSW SES says floodwaters flow into the valley more quickly than they can flow out, which is why they back up. The 1961 flood peaked at about 15m at Windsor, 1m above the July 2022 floods, and the 1867 flood reached 19.7m at South Windsor.
Mosquitoes after high water
NSW Health says stagnant water provides ideal conditions for mosquito breeding. Its list of common sites reads like a flood clean-up: buckets, pot plants and their bases, plastic containers, boats, trailers and tarpaulins.
Trap results nearby
NSW Health's North Richmond trap site in the Hawkesbury returned Gan Gan virus on 8 April 2025. A virus in a trap isn't a human case. It's a reason to keep standing water down and cover up in the evening.
After high water
Follow the NSW SES first
Pests can wait. Don't go back until it's cleared, and leave anything electrical or structural to the right trade.
Tip out what held water
Empty containers and boats, and check trailers and tarps. Clear debris from drains you can reach, so water moves on.
Look for new ways in
Check for gaps, shifted boards and damaged vents. Rats and mice go looking for dry shelter.
Get damp timber looked at
Timber that stays wet suits termites. If you find mud tubes or damaged wood, don't disturb them. Book an inspection.
Rodent control in Windsor
CSIRO said in May 2021 that cooler weather encourages mice to find shelter inside homes in NSW and Queensland. Around Windsor, stored feed, compost and stacked timber give them reasons to stay. A good rodent job starts with finding how they got in, then the bait stations (locked boxes that hold rodent bait) or traps go where they'll do the work. See our Sydney rat and mouse page.
Buying near the river?
A building report won't show whether termites are still around, so NSW Government advice is to get a pest inspection as well. They're separate jobs. Ask each inspector about insurance, and read our Sydney pre-purchase page before exchange.
Our take on pests in Windsor
Once the water's gone, deal with standing water first, then look at how mice might be getting in. If timber stayed wet, book a termite inspection. Tell us what you've seen, with your postcode.
Want someone to look at it?
Tell us what you've seen and your postcode, and a local pest business that handles exactly that calls you to talk it through.
