A display area to showcase the children's artwork, predator traps and picnic tables will also be included in the transformation.
"We are over the moon that our school has been chosen to receive a Treemendous School Makeover," said Argyll East principal Mark Thompson.
"We're excited to transform our outdoor area and develop the banks of the Mangaotai Stream, which will benefit the community as well as the school, and students can immerse themselves in nature, during both class and playtime."
Project Crimson Trust chairman Joris de Bres said it was nice to see schools around the country embracing the importance of conservation and outdoor education.
"All of the entries we received this year were of high calibre, and really showcased the creativity and enthusiasm for the environment in schools around the country."
Since the programme began in 2008, 31 schools have benefited from the Treemendous makeovers.
All primary and intermediate schools can apply for a Treemendous School Makeover. Finalists receive $500 for their school and the winning four schools receive a $10,000 Treemendous School Makeover. Entries will open again in the first term of the New Year.
On behalf of the Mangaotai riparian committee made up of children and members of the school committee, Argyll East teacher Rose Hay thanked a number of people and organisations for the work done so far on the project.
These included: Aaron Topp of Hatuma Limes for six truckloads of lime, Twist Trucking for transporting the lime free of charge, Centralines for taking down the dead tree and supplying mulch all free of charge, Burke Olsen for the free hireage and use of his digger, school parents who removed trees and sprayed the area and the Rivers Trust for their grant that was used to employ the services of The Conservation Company to spray blackberry and periwinkle on the Mangaotai banks.