The work is being done by Enviro360 and will cost about $250,000.
While the work is being carried out, dogs and their owners can use the temporary dog park on the other side of William Fraser Memorial Park on Pohe Island, beside the Hatea Loop walkway, towards the Madhatters Football clubrooms.
The temporary dog park has a boundary fence, it can be accessed from the loop walkway and parking is near the skatepark, off Riverside Drive.
Plastic bags, rubbish bins, water for dogs and some seating will be provided. Water stations for people are along the loop walkway close to this area.
The council said the group that helped manage the dog park have made many suggestions for improvements and year by year it is becoming better and better for users.
The council had done some drainage work there in November 2017.
Whangārei Dog Park committee spokesman Tony Gill said this latest lot of improvements would be brilliant.
"This should finalise the drainage issue over winter."
He said the ground was still quite boggy in winter, causing people had to wear gumboots.
Gill said the dog park was being used more and more, particularly after the committee - with the help of sponsors - installed a shelter midway through last year.
There are other things, such as lights for the winter and cameras, that he would still like to see installed at the site, he said.
The committee was seeking sponsors for a dog seesaw and hoops for the dogs to jump through for the agility area of the dog park.
