LETHBRIDGE, Alta. -- A southern Alberta man has been sentenced to 15 years in jail for a vicious sexual assault on a woman who spent weeks in a coma and was forced to learn how to walk and talk again.

Denzel Dre Colton Bird, 21, pleaded guilty last fall to striking the then-25-year-old woman from behind with a metal pipe, dragging her into an alley and sexually assaulting her in September 2016.

She was walking to work when she was attacked.

The blows caused multiple skull fractures and broken facial bones.

"This court, regrettably, can never make right or repair the harm done by such a criminal act," Judge Jerry LeGrandeur said Friday.

"The criminal justice system is not designed to heal the suffering of victims of crime."

LeGrandeur sentenced Bird for aggravated sexual assault and an additional charge of break and enter.

The judge gave Bird 2 1/2 years of credit for time already served.

LeGrandeur said the viciousness of the attack on the woman was an aggravating factor.

"The consequences of this criminal act were profoundly physically and mentally disabling for the victim and emotionally traumatic and debilitating for her husband and family members."

But LeGrandeur said there were mitigating factors in Bird's favour including his youth, his guilty plea and the fact he was remorseful.

He also cited from a Gladue report, which examines an Indigenous offenders upbringing and background that had to be factored in.

LeGrandeur noted that Bird's family were survivors of residential schools. He was also abused as a child and has lower than average intelligence.

After sentencing the victim's stepfather said what happened has been nightmarish and no sentence would undo what was done to his "little girl."

He said she is making some progress in her recovery and the sentence will give the family some closure.

The Crown had requested 20 years in prison.

"It's still a significant sentence. He's a very young man yet and has a long life in front of him and I think this is the kind of sentence that sends a message to the public but also ... allows the potential for him to address some rehabilitation," said Crown prosecutor Erin Olsen.

Jeanine Zahara, appearing on behalf of Bird's lawyer, said Bird was disappointed.

"He's obviously very upset with the outcome. He was hoping for a sentence under the range of 10 years. He's indicated that he will be appealing his sentencing."

At a hearing in April, the woman wrote in her victim impact statement that there have been times that she wished she had not survived the attack.

"I am not the same person I was," she said. "At times I even wished Bird had finished me off, but then I remember how strong I am and I don't want to give him that power over me.

"I'm more alive than ever. He hasn't taken away my will to live. I am a survivor."

The woman said she struggles with her emotions, has trouble with her balance and contracted a sexually transmitted disease from Bird.