Our strong reputation is built on a foundation of close client relationships and an outstanding track record in all aspects of Earthworks
Our strong reputation is built on a foundation of close client relationships and an outstanding track record in all aspects of Earthworks
Hiwinui
WetLand Drainage
Project Overview
Alistair Davis faced persistent drainage issues in his orchard, preventing Feijoa trees
from thriving. The wet ground beneath the trees, ineffective previous
drainage, and a
low-lying area falling in the wrong direction contributed to poor growing conditions.
Additionally, an overgrown road drain and a blocked culvert exacerbated water retention
in the area.
Challenges & Site Considerations
Limited access due to fencing, tree stumps, and an abandoned shed.
Presence of a water line requiring careful excavation.
A main telecommunications cable to trench over without damage.
Blocked road culvert filled with debris and mud, restricting water flow.
Solution & Executi
To resolve these issues, a comprehensive drainage system was implemented, including:
1. Site Preparation & Access:
Demolished and removed the abandoned shed.
Removed a section of fencing for equipment access.
Cleared agapanthus obstructing the road drain.
2. Drainage System Installation:
Excavated and strategically trenched 120m of drainage to direct water flow effectively.
Used 110mm punched drain flow pipe with a filter sock, laid in a 450mm wide trench graded at 1:100 (1%).
Surrounded the pipe with 14-19mm washed drainage stone, covered with filter cloth, then overlaid with topsoil.
Access points installed at all junction
Installed clean-out points at the end of each drainage run for future maintenance.
3. Land Regrading & Replanting Preparation:
Imported and laid 50m³ of screened topsoil over the affected area.
Raised up the low-lying area and built a planting bund for new Feijoa trees (to be planted by the client).
4. Final Site Restoration:
Reinstated the fence after completion.
Burned and buried tree stumps, shed remains, and fence debris on-site.
Reshaped the drain and cleared the road culvert to restore proper water flow.
