Dormer Construction

Mt Beautiful Wine Earth Dams

Mt Beautiful Wine Earth Dams LOCATION Spotswood
CLIENT Mt Beautiful Wines
VALUE $365,000.00
PROJECT START November 2013
COMPLETION February 2014

SCOPE

Making use of a natural valley watercourse, and storm water capture, Mt Beautiful resolved to create two low-height, low-capacity earth dams to service irrigation needs across significant areas of vineyards and grape varieties. Dormer assisted the site developer with design input for the concrete spillway and embankment proposals.  The large spillway was formed to take a base flow along with capacity to convey a 1% AEP*. This spillway was partially lined with concrete (to convey a 5% AEP) with erosion matting outside of this area for the larger flows. Topsoil was stockpiled and placed over the dam embankment upon completion and used to ease contours.  This agricultural  bulk earthworks scope included; stripping of site topsoil from cut and fill areas, excavation of cut material and cart to fill areas, proof rolling base and undercutting weak material, compaction of earth-fill, placement of topsoil, placement of wave armouring and grading.  Old watercourses within the valley floor were dug out to clean material.  The borrow for the fill was from a gravel colluvium bank adjacent the dam site. The bank was cut back vertically (as had been in the past). During the construction a siltstone was uncovered and this was used for the core of the dams as the permeability of this material was low.  Two dams were formed by Dormer. Dam 1  being 145m long 4.5m high 30m wide consisted of 14000m3 of earth moved during the preparation and building of the dam. Dam 2 112m long x 3.5m high x 24m wide consisted of 15000m3 of earth moved during the preparation and building of the dam.

PERFORMANCE

Environment

Works were carried out in accordance with the requirements of NZS4431 and NZS4402. Achieved compliance with ECcan requirements.  Silt and sediment controls installed.

Health and Safety

No accidents during this contract.

Programme

Works were subject to rigorous field tests (maximum dry density) and site quality inspections recorded by Dormers engaged Engineer.  Achieved 8 week physical works construction programme.

Cost/Budget

Negotiated contract.  Maintained Cost Plan.