ala wai canal stations

Station G8 located at the southeastern (Diamond Head) end of the Ala Wai Canal.  Circulation at this station is very limited since there are no major streams flowing into the canal at this point.  The connection to Mamala Bay is at the opposite end of the canal.  The entire canal receives storm water runoff from the many streets surrounding the canal, including the Waikiki area.

Looking makai from Station G8 toward Waikiki.  This urban area is very heavily developed with large amounts of vehicular traffic.

Looking mauka from Station SILL on the Ala Wai Canal at the point where Manoa-Palolo Stream enters the canal.  Our Station KHS is located about 850 m upstream of this point.  Station SILL gets its name from the fact that a sill is formed at this point where the higher velocity flows of the stream enter the canal and slow down thereby depositing sediment on the bottom forming a sill.

Looking down the Ala Wai Canal from the vicinity of Station SILL on a rainy day.  Note the debris that has been carried to the canal from the various streams and storm drains that empty into the Ala Wai Canal.  In addition to this very visible form of pollution, other less visible pollutants such as suspended sediments, nutrients, bacteria, oils, and trace metals also are introduced into the Ala Wai Canal on days like this.

Looking across the Ala Wai Canal towards the Hawai'i Convention Center from Station M3.  This station is located just downstream of the Kalakaua Avenue bridge that crosses into Waikiki.

Quarterly sampling at Station M3 on the Ala Wai Canal.  During quarterly sampling, we manually collect grab samples for trace metals and major ion analysis, measure temperature, conductivity, dissolved oxygen, pH, and turbidity in situ with a YSI 6920 water quality sonde, and record various meteorological and environmental observations.

Looking down on the Ala Wai Canal (below the Ala Moana Boulevard bridge) in the vicinity of our Station YC (Yacht Club) the day after a storm washed large quantities of debris into the canal.  Although floating booms retain some of this debris, much escapes into the canal and eventually Mamala Bay.  These booms generally do not retain the suspended sediments or other pollutants. 

We collect various kinds of data in a relatively wide area designated as Station YC.  Quarterly samples are collected in this area but closer to the Ala Moana Boulevard bridge.  In the area shown in this photo, we are experimenting with a passive sampler that uses diffusive gradients in thin films (DGT) to sample dissolved trace metals.

A photo of Le'ahi (Diamond Head) taken from the vicinity of our Station CHAN located in Mamala Bay.

Looking back toward shore from Station CHAN.  The trace metals concentrations measured at this station are some of the lowest, however, it is primarily due to dilution by relatively clean ocean water.