A group of high school girls helped to save the life of a woman who plunged from her mobility scooter into the Waikato River today.

Hamilton police Senior Sergeant Wayne Petherick said the woman fell about 20 metres from a walkway into the river, near the old Waipa Delta pier, about 1:30pm.

The Sacred Hearts Girls' College students had been walking back from a Phy Ed lesson at Memorial Park when they saw the woman, believed to be elderly, go ''careening'' down a path, over the embankment and into the river, school principal Chris Allen said.

''The girls were coming back from class and saw the woman and ran after her,'' she said.

''They saw her go over the bank and into the river. Then they saw the mobility scooter pop up and then the lady, and so they held her up while others rang the ambulance and directed the emergency services to the right location.''

The students are in year 11, aged 15 and 16, she said.

''The teacher was saying she was very impressed with the girls, that they kept calm and did all the things they needed to do without being asked or told. They didn't panic and just got on with things.''

Ms Allen said she had spoken to one girl involved in the rescue who simply said: ''We did what we needed to do''.

''I am the proudest principal in the Waikato today. I am just so impressed with what they did. I am so, so proud.''

Craig Peden's daughter Jess, 15, was one of the rescuers, and did not even tell her parents what had happened.

''Jess is quite a shy girl and I only found out when the principal rang me,'' he said.

''I am just blown away by what she did, what they all did.

''I am just rapt. I don't know what word to describe what I am feeling. I am over the moon.''

The woman has been taken to Waikato Hospital.

''At this point we don't know the extent of any injuries or if her mobility scooter landed on her in the fall,'' Mr Petherick said.

''Either way the people involved in her rescue have every reason to be proud of their actions.''

He said police would be looking at a way of recognising the heroics of those involved.  

- © Fairfax NZ News