Grove Farm Launches $1.1 Million Tunnel Repair

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Grove Farm in September 2017 will launch $1.1 million in repairs to the 100-year-old hand-dug Kapaia Tunnel, which feeds Kapaia Reservoir.

The maintenance project is needed after repeated collapses, some of which reduced water flow in the 10-foot-wide, 3,000-foot-long irrigation tunnel. Two significant collapses occurred in April and August of 2016.

Kapaia Reservoir, also known as Tanaka Pond, supplies Grove Farm’s Waiahi Surface Water Treatment Plant. That plant feeds drinking water supplies to the county Department of Water’s Lihue-Kapaa water system. Nearly 15,000 residents are on the water system.

The reservoir also supplies irrigation water to numerous farms, ranches and other businesses. A restoration project for the Hawaiian state bird, the Nene, is situated at the reservoir.

Grove Farm repaired the first 2016 collapse with an $84,000 debris-clearing effort, but a second major collapse occurred just two months after repairs were complete.

To restore stable flows and avoid the risk of future collapses, Grove Farm will install a 36-inch-wide high-density polyethylene pipe for the entire 3,000-foot length of the tunnel. Work is expected to start in September 2017 and be completed by December 2017.

During this 4-month construction period, all helicopter tour pilots have been requested to avoid flying over the tunnel area.  The vibrations caused by the helicopter blades have resulted in repeated collapses. 

This large tunnel is but one component of a complex water system, stretching miles across the landscape, including reservoirs, dams, open and covered ditches, flumes, siphons, water treatment facilities, and other tunnels.

Grove Farm continues its commitment to responsible stewardship, leading Kaua’i’s community and economic development, and preserving Kaua’i’s precious resources.