The dog's owner had just finished walking on the trails at Table Rock when it went in into the water.
Paul Whitworth's wife Carrie heard a loud yelping and went down to get her dog Jasper out, not realizing the water was around 170 degrees. By the time she was able to get him out of the water it was too late.
"You know he yelped and went out howling. I'm sure it was pretty painful," said Paul. "He was burned. He had really bad burns all over his body. It was a pretty traumatic ordeal."
The pump station at the base of Table Rock supplies geothermal water to hundreds of customers. Normally there is so much demand it doesn't give it a chance to overflow into the ditch.
Due to nearby construction the Boise Warm Springs Water District had to shut off its pumps for safety reasons. This caused the water to build up and flow into the ditch.
Water Board Chairman Patrick Frischmuth said it's so rare it hasn't even happened in recent history. He noted they were discussing the issue just two days before the incident.
"We were actually in discussion about how we need to deal with this exit and trench here because of the public safety threat," said Frischmuth.
They had checked it on Saturday and no water was flowing up, but it ended up flowing up on Sunday when the dog jumped in.
Frischmuth said they are trying to work with the City of Boise to create a piping system that will store it underground like a septic system. Although, when it would be finished remains to be seen.
For now, the district has put up a temporary fence and signs to warn people.