Lake Eppalock Holiday Park owner Peter Rose says this summer has been the quietest yet in his eight years of owning the business, due to the reservoir's low water level and blue-green algae.
As of January 9, Lake Eppalock was at 30.09 per cent capacity, its lowest level in about three and a half years.
Read more: Eppalock just one-third full
Mr Rose said bookings started to drop after a blue-green algae alert was issued last month, and close to Christmas they were hit with cancellations.
"We just really need the weather to change... The lake's built for irrigation, the irrigators need their water, so we need the right amount of rain," he said.
Bendigo Yacht Club commodore Andrea McGregor said sailing had not yet been affected, but if the water level dropped much lower sailors would not be able to use bigger boats.
But Ms McGregor said 'off the beach' boats could be used in less water, and had been sailed when the water was as low as 18 per cent.
Mr Rose said he tried not to let the conditions concern him too much, with the park having added such attractions as a petting zoo, outdoor theatre, beach volleyball court and other options for activities to give people a good time off the water.
As it got drier, he said, they would need to try more things that would attract visitors, and be smarter in how they invested money back into the park.
A blue-green algae alert remains in place for Lake Eppalock.
Goulburn-Murray Water advises people avoid contact with the water because of high levels of the algae.