Cars filled every car park and lined the streets near the school as about 800 people arrived to celebrate her life.
The 17-year-old head girl of Cromwell College died on December 20 as the result of a medical event, leaving a hole the hearts of the community.
The celebrant officiating at the funeral, Dave Ramsay, said the ''huge'' number of people attending was a mark of the respect held for Rachel and a show of support for her family.
So many people were assembled a live video feed from the school auditorium was set up for those seated in the school gymnasium to watch the ceremony.
The celebration of Rachel's life was marked by tears and sadness, but there were also laughter and smiles as people paid tribute to a ''young life lost''.
Mr Ramsay said the image he had developed of her was of a caring, vibrant, wise-beyond-her-years young woman.
During his eulogy, Rachel's father, Tony Clark, said she ''was not one for dark moods or depressing thoughts''.
''We have had a whole week to reflect on her life ... We would like to give you a few laughs at Rachel's expense now. I'm sure she would have laughed too.''
He thanked the people of Cromwell for their support, and said they should be proud of their community.
He recounted his memories of Rachel.
When younger, she would often disappear at home.
''When she went missing, you could find her in whatever fruit tree was in season in the garden.''
Although she raided the berry bushes, ''veges weren't her thing'', he said.
She was determined from a young age and she mastered skiing early. Mr Clark recalled racing her down skifields - and her letting him win.
''She hated coming second ... and struggled with others who were not as determined.''
An all-rounder, she was a ''voracious'' reader who embraced the Harry Potter series, reading the books about seven times.
She used to walk to school reading, and once walked into a car while her head was in a book.
He recounted other characteristics.
Rachel had a strong sense of wisdom and moral behaviour, he said.
''She never gave up on people.''
During emotional speeches, Rachel's sisters, Rebecca and Nicola, said they had lost a member of their ''tight five'' family group.
The family had lit and placed candles on her casket, which was also adorned with flowers from teen pop star Lorde, of whom Rachel was a fan.
Other speakers, including her former employer, rowing coach, and teacher, made heartfelt tributes to her.
A common theme among all those remembering Rachel was her maturity, leadership and communication; an intelligent youth with a dedication to all aspects of life and willingness to ''give it a go''.
After a period of reflection, during which a slideshow of images of Rachel played, her casket was taken from the auditorium by family, surrounded by a guard of honour.
Outside, friends and school mates preformed an emotional haka to bid her farewell.
Mr Clark asked that rather than give flowers, people donate to a trust set up in Rachel's name.
The Rachel Clark Memorial Trust would help someone who might not normally get financial support to achieve their goals.
