A Northland police spokesman said the child's identity would be released once the Coroner gave the go-ahead.
It's understood the child lived locally and a post mortem is expected to be conducted on Monday.
It was the 31st death this summer throughout New Zealand.
Also on Saturday, a person was found unresponsive in the water at Mount Maunganui and was transported to Tauranga Hospital in a critical condition.
Northland's first water-related incident occurred on Tuesday last week when four-year-old Shakib Tahir could not be revived at Kai Iwi Lakes.
Hikurangi Coastal Ward Councillor Anna Murphy whose area covers Whananaki North said two water-related deaths in Northland in such a short space of time is "absolutely tragic".
"Unfortunately it's happening too often. One only has to turn their back for a minute and things can get out of control. Everyone loves swimming and cooling off but the water can be dangerous if people are out of their depth.
"People have to have respect for water. I have three sons and over the years we've had occasions where all of a sudden you are like 'oops, you've gone out too far or you get knocked by the waves' and that's why it's important to teach our kids good water skills,"
Murphy said.
Water Safety NZ believes the months-long lockdowns for Auckland, Northland and Waikato may have encouraged people to try things they hadn't done before, overestimate their fitness, or delay the servicing of equipment.
"In line with that it could also be dive equipment, or your motor in your boat ... and you're out somewhere and potentially your equipment fails. "We're hearing a lot of that anecdotal stuff, that dive equipment is not serviced," Water Safety NZ chief executive Daniel Gerrard said.
