Ala Wai

"waterway"

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In and around

(Map Image: Honolulu Water Commission 1912)

Expanding around the south shore of O'ahu stretches the Ala Wai Canal, a 2 mile long man-made channel, its name literally translating to "waterway".  It separates Waikiki from Ala Moana and McCully-Moilili sitting as a show piece surrounded by recreational and business areas. This canal merges the Makiki, Palolo, and Manoa streams then runs into the heart of Waikiki out into the ocean at the Ala Wai Harbor. Originally these streams once branched out across Waikiki and reached the ocean on their own, until the Canal was made around 1921 and was incompletely finished in 1928. The Ala Wai currently faces issues of flood risk & pollution from due to many different sources of urban runoff. In addition, its past is quite enlightening and clues us into the ongoing importation dependence.

Following the streams

Beginning in the Ko'olau mountains several streams branch and converge. The streams from the past "Pi‘inaio, ‘Āpuakēhau, and Ku‘ekaunahi streams, fed by the Ko‘olau watershed, drained into the ocean at beach sites in Kālia, Uluniu, and Hamo-hamo, respectively" (Chan & Feeser, 2006).  Now they have different names and some different routes: we roll down from Palolo and Mānoa streams. The two streams merge around Koali Bridge forming the Mānoa-Palolo Drainage Canal. We pass bustling businesses, Kaimuki High School, then curve into the Ala Wai Canal.   Then, Makiki stream lays underground and enters the Ala Wai near the Hawaii Convention Center. The water then exits at Kahanamoku Lagoon (between Ala Wai Harbor and Magic Island) washing into the ocean.


The Ala Wai Canal cuts off the flow of Hawai'i's natural branching rivers and pools that were spread through the base of Waikiki. These original streams were important to the ecosystem. The wetlands and the estuary areas were filled with wildlife and Waikīkī  in particular grew lots of limu līpoa which also attracted fish. This drainage of the wetland, channelization of the stream, and impermeable surfaces catching rainfall caused a lack of filtering and overall decrease in water quality further down the stream.

Hydrography Features

Water Quality 

affected by urban runoff, untreated sewage incidents, and other pollutants. Urbanization and impermeable surfaces created by it cause for excess runoff that eventually drains into the Ala Wai Canal causing it to flood when it heavily rains.

The report linked analyses the Ala Wai Small Boat Harbor's water quality to determine how the Ala Wai Canal's pollution was affecting the ocean, this data is based off of 10/15/2019. Results that were tested: temperature, salinity, pH (freshwater should be near 7.0, ocean buffers should be around 8.2), turbidity (should be low, clarity, solids/algae in water), bacterium (Enterococcus & Clostridium both indicate sewage spills), dissolved oxygen (%, mg/L). They took samples from 12 different sites around the area, especially where the canal water would flow. The report concluded that "while the Ala Wai Canal water quality is poor, there does not appear to be wastewater flowing into the Ala Wai Small Boat Harbor."

Mauka

Directly inland from the Ala Wai Canal are the recreational and educational places Ala Wai community park, Ala Wai golf course, 'Iolani school and Ala Wai elementary.  Where McCully-Mo'ili'ili and Kaimuki meet there sits a bit residential and business area. There are also many educational institutions that the stream wraps around.

Makai

Waikīkī, a huge tourism and business hub on 'Oahu. It’s a driving source of the economy which is clear in the sheer amount of tropical advertising from hotel resorts & beaches. Originally a wetland of streams and springs that was tended to by local farmers. It's labeled unsanitary leading to the creation of the Ala Wai Canal to drain its wetlands. 

East

Kaimuki is one of the oldest neighborhoods, prime local business and recreational area.

Diamond Head/Lē‘ahi which formed as a volcanic tuff cone, its Hawaiian name reflecting a tuna's dorsal fin. The hike to the summit was originally created for coastal defense in 1908. A Fire Control Station sits at the top to support artillery fire from Waikīkī.

West

Ala Moana, a shopping district marked especially by the Ala Moana Mall.  One of the biggest malls in the United States.

Magic Island is a man-made extension of Ala Moana Beach Park. The materials were gathered from the dredging of Ala Moana Beach done to open the Ala Wai Canal into the ocean.