A County Court judge has described a violent rape alongside a Melbourne creek as "every woman's worst nightmare", saying the man responsible was "an extreme danger to women".

WARNING: This story contains details that readers may find distressing.

On Wednesday, the County Court heard how Joel Russo repeatedly raped his female victim, who was jogging along the Merri Creek trail in Coburg on the evening of December 3, 2019.

The incident sparked community outrage and calls for improved safety measures, with hundreds taking to the streets for a march of solidarity.

Judge Liz Gaynor, who described Russo's attack as "appalling", "degrading" and "terrifying", made the remarks during a pre-sentence hearing, after 28-year-old Russo pleaded guilty to rape and other sex offences.

"To any woman this reads like a chamber of horrors," the judge said of the attack.

Rapist held woman's head underwater during attack

The court heard harrowing details of what unfolded during the attack on the 26-year-old woman, who did not know Russo.

Crown prosecutor Jane Warren said Russo approached the woman from behind, and dragged her down a steep embankment and into the creek.

"[The woman] continued to scream and tried to break free. She was unable to do so. She clawed the ground to try to stop Russo dragging her into the water," Ms Warren said.

Ms Warren said Russo threatened his victim, saying he would only let her live if she agreed to having sex.

The court heard Russo held the woman's head under the water, and then repeatedly raped her over a prolonged period. To avoid being seen, Russo pushed his victim into the bushes when others on the trail were nearby.

After the attack, Ms Warren said Russo made the woman hold his hand as they walked through the streets.

"He asked if she was going to visit him in jail, and she said no. He said, 'Sorry for raping you. I've ruined your life, haven't I?'" Ms Warren told the court.

The woman was able to escape after clinging onto a metal pole outside a fast food restaurant, and then raised the alarm when Russo walked off.

"She was crying. Her clothing was wet and dirty. She had twigs and leaves in her hair," Ms Warren said.

Russo, who has an intellectual disability, was arrested early the following morning.

DNA evidence linked him to the attack.

After protesting his innocence and fighting the charges during several court hearings, he formally agreed to plead guilty in October last year. A suppression order over media reporting of the case was lifted on Wednesday, after an application by the ABC.

Russo watched proceedings from prison via video link and was not required to speak, other than to enter guilty pleas.

In a victim impact statement, Russo's victim said she felt anxiety, depression and post-traumatic stress after the incident.

"Thinking about it causes disgust, anger, hurt, fear and frustration," she said in a statement, read out on her behalf.

"There is no way I can accurately convey the enormous burdens I carry with me."

Judge fears rapist will receive little clinical support during imprisonment

The court heard Russo was previously jailed for rape and sexual assault in 2015, when he attacked a 16-year-old girl. He faces a maximum jail sentence of 25 years for the Merri Creek offence.

Judge Gaynor said she was disturbed by Russo's past, which included being born to a drug-addicted mother, a childhood where he was abused and multiple attempts to take his own life.

"I'm satisfied he suffers from a pervasive intellectual disability across all realms of functions. This appears not to have been properly recognised or picked up," Judge Gaynor said.

The judge expressed frustration that Russo received little clinical support during his previous imprisonment and after he was released into the community last time. She said she worried the same would occur again.

"The only place he feels comfortable in, is in institutions," she said.

"He has inflicted a sexual ordeal of horror on his victim."

The hearing continues.