Permanent opening - 500m mole (Mr Langbein's plan)
Description of option
A permanent opening consisting of a mole bypassing gravel around the opening was proposed. This design used the Timaru experience as a guide and was designed with the mole extending seaward for 25 chains (500m). Provisions were included for an extension to the mole to be under taken in future if necessary.
Opening, closing, and lake level control description
1932 cost: 110,000 pounds (using rock from Birdlings Flat run along the spit on a tramway)
Fish passage benefit rating
Potential running impacts or benefits