Project elements


The United States Senate passed legislation for more than $212 million in federal funding for the Ala Wai Canal Project. The Ala Wai Canal Project is a flood mitigation project created by the USACE. Read on to see what this project includes and the impact it will have on Oahu's land and residents. 

Project Elements

  • Concrete wall around Ala Wai Canal

  • Embankment around Ala Wai golf course

  • 7 large detention basins near residential areas

of concern


Appendix E: page 748

Concrete Wall Around Ala Wai Canal


Appendix E: page 549

Appendix E: page 549

Dimensions: 4ft. high concrete wall along the Ala Wai Canal, projected to be 1.9 miles long


Objective: Prevent the canal from overflowing into Waikiki

(When was the last time you saw the canal massively overflow?)


Earth Embankment Around Ala Wai Golf Course


Appendix E: page 625


Appendix E: page 550

Dimensions: 4 ft. high man-made earth embankment around the Ala Wai Golf Course

Objective: Golf course turns into a detention basin to prevent floodwaters from flowing into Waikiki

Detention Basins

1) Kanewai Field Detention Basin

2) Woodlawn (Manoa Valley): on private property that will be seized

3) Waihi (Manoa Valley)

4) Waiakeakua (Manoa Valley)

5) Pukele Detention Basin: 13 private properties will be seized from families

6) Waiomao Detention Basin: 6 private properties will be seized from families

7) Makiki Detention Basin

Kanewai Field Detention Basin

ala wai canal

Appendix I: page 15


Appendix E: page 617​

Read letters that call for the reconsideration of the Ala Wai Canal Project.

Location: Encompasses all of Kanewai Field located above Hokulani Elementary School


Objective: Use existing open space to temporarily contain floodwaters



  • Maximum volume: 900,000 cubic feet (a football field filled 16 feet high with water)

  • Stormwater will be detained by a man-made 9-ft tall earth embankment 

  • Poses risk to residents downstream should basin ever overtop or fail

  • Negatively affects the park’s use by the community and Hokulani Elementary school

  • Becomes a safety hazard to children and pets when basin is filled


Woodlawn Ditch Detention Basin (Manoa Valley)


Appendix I: page 54​

woodlawn ditch.png

Location: Just below the Chinese Cemetery in Manoa Valley on farmland bounded by East Manoa Road, Kolomona Road, and Lower Place. The structure does not interfere with the houses off of Kolomona Road, but does encompass the farmland below the cemetery. Spans over Woodlawn Ditch. 


Objective: Control the flow into the Woodlawn-Manoa confluence and divert floodwater further downstream. This design assumes that slightly less than 750cfs is a safe flow rate for Woodlawn Ditch and that the diverted water will not have an adverse effect on flows downstream. It also assumes that with the 100-year flood, all water can be contained within the basin and there will be no need to use the emergency spillway unless these floodwater rates are exceeded.



  • Stormwater will be detained by a man-made structure 20-ft high  

  • Poses risk to residents below should basin ever overtop or fail 

  • A safety hazard to children and pets when filled


Waiakeakua Detention Basin (Manoa Valley)


Appendix I: page 13​


Waihi Detention Basin (Manoa Valley)


Appendix I: page 12


Pukele Detention Basin (Palolo Valley)


Appendix I: page 20​

  • Structure will be 33ft. high, 180 ft thick, 400 ft. long

  • Includes 100ft. wide spillway

  • Designed to hold 1.1 million gallons (equivalent to a football field filled 30 ft high with water)

  • 13 private properties will be seized from families for this structure to be built

  • Will destroy almost 1,000 ft of natural stream

  • Stream & land will be excavated and ripped out to create the volume capacity

  • 14,330 cubic yards of material plus vegetation will be removed which could amount to 3000 truckloads going up and down the already-damaged roads of Palolo

  • Poses risk to residents downstream should basin ever overtop or fail

  • Becomes a safety hazard to children & pets when basin is filled

  • Palolo Valley by itself doesn't need flood protection, this detention basin is meant to catch water and prevent it from stopping in the canal.

  • Why should the Palolo Valley residents carry the risk of danger?


Waiomao Detention Basin (Palolo Valley)


Appendix I: page 16​

Makiki Debris Detention Basin

makiki basin map.png

Objective: Designed to hold over 8.7 million gallons of stormwater (the equivalent of a football field filled 20 ft. high with water



  • Structure will be186 ft. thick, 100 ft. wide, and over 33 ft tall. 

  • Public charter school, Halau Ku Mana is located on TMK 25020004 (see above)

  • Earth embankments will affect views of residents and those who travel on Round Top Dr and Makiki Heights Dr.

  • Will destroy approximately 800ft of natural stream and acres of land

  • Pose risk to residents downstream should basin ever overtop or fail

  • Safety hazard to children and pets when filled

  • Man-made eyesore