Mawaihakona Stream

The Mawaihakona Stream (also known as Māwai Hākona Stream) is a small watercourse in Upper Hutt, in the North Island of New Zealand. The stream begins at a spring in Trentham Memorial Park and drains the western side of the Hutt Valley from Trentham to Heretaunga. The stream passes around Heretaunga Park and the perimeter of the playing fields of St Patrick's College, Silverstream. It flows into the Hutt River north of the Silverstream bridge.

Toponymy
The word Mawaihakona means "stream where water was scooped out". The name Mawai Hakona was the Māori name for the Trentham district, and was formerly used as the name for a settlement near Trentham railway station.

Environmental restoration
An environmental restoration project for the lower reaches of the stream began in 2002. The two founders of the project were Bart Hogan and Graeme Bennett. At that time, the banks of the stream were infested with invasive species including gorse, broom, blackberry, crack willow, acacia, alder and poplar. The purpose of the project was to remove weed species and revegetate the stream including planting lowland podocarp species that were present in the area prior to settlement. The restoration project included removal of invasive species from the banks and the bed of the stream, and planting the banks with native species. The planting has included forest canopy tree species such as rimu, tōtara, mataī and kahikatea. Pathways, bridges and seats were built to provide walkways through the planted areas. The work has been carried out mostly by volunteers, with support from the students of the nearby St Patrick's College, Silverstream. The native plants have been raised by the group or funded through donations. The group Friends of the Mawaihakona Stream became a registered charity in 2014. By 2020, over 10,000 trees had been planted.

The stream bed has been infested with the invasive cape pond weed. Control of this weed is a priority for the restoration, and requires roots and bulbs to be removed by hand.

A fish ladder was constructed by Wellington Regional Council to assist fish to enter the stream from the Hutt River. Surveys of fish in the stream have revealed that eels, koura and inanga are present.

During the removal of willow from the stream, an 18 m tōtara log was discovered. This was used to create large marker posts (pou rāhui) at each end of the replanted section of the stream signifying that the planted area has a rāhui or protected status.

In 2020, a proposed major land development was announced for land immediately adjacent to the restored stream banks. The land is a flood plain of the Hutt River. To allow building on the site, the proposal was to raise the level of the land by 3 m, requiring the placement of 550,000 m3 of fill, in a project that would take 5 years. The proposal could involve reducing the protected reserve margins of the stream from 20 m to only 12 m, and this would eliminate around half of the planted area.

Awards
In August 2023, the Friends of the Mawaihakona Stream received both the Heritage and Environment Award and the Supreme Award in the 2023 Wellington Airport Regional Community Awards - Upper Hutt. The project also won the Environmental and Sustainability Award at the 2024 Hutt Valley Sports Awards.