Waimahaihai Gulch Stream

The journey of the Waimahaihai stream: Waimahaihai Gulch starts high on the southeastern ridge of Haleakalala at around 7,000 feet above sea level. It crosses the Skyline hiking trail, and flows downhill into Kula Forest reserve, past Hawaiian Homelands, over Haleakala Ranchlands, past two Solar farms, then flows between the Maui County Water Reclamation Facility (sewerage treatment plant) and the Maui Nui Golf course, crosses the Pi’ilani Highway through an under-road culvert, flows across Hope Chapel owned land,  through a residential neighborhood along a privately-owned streambed, crosses Malama Street, flows along another section of privately-owned streambed, and then enters a widening of the gulch that forms a large 10.5-acre basin on private land.  This area is one of Kihei’s largest original wetlands zones fed by multiple streams, This floodplain wetland zone connects with Welakahao Wetlands all the way down to Kalama Wetlands. From here the stream can overflow outwards across the roadways at South Kihei Road and Kupuna Street.

Waimahaihai Gulch Stream Diagram

Malama Street Crossing: This is the stream-crossing for the Waimahaihai stream that crosses Malama Street.  The gulch’s streambed on both sides of the crossing is choked up with plants and debris so it is very hard to actually see that it is a steam bed.

Waimahaihai stream at Malama Street

Streams become Stormwater Drains: Part of the urban watershed landscape are many streams that have been converted into stormwater drains. Natural streams are tasked with disposing of stormwater. Commercial and Residential developments use Streams as Drains for their rainwater runoff. Natural streams are hard to discern in the urban environment. Read More about When streams become Stormwater Drains.

Waimahaihai Stream floodway shown in red (source: Maui County TMK viewer)

Streams Forced Underground: Streams including Waimahai Stream are forced underground in urban areas. Stormwater drains are used because the developers have taken all of the lands away from the streams. In stormwater drains, streams are so severely restricted that they lose many of their beneficial functions, and turn into a “nuisance” rather than a valuable resource.

Waimahaihai Stream storm drain. Photo: D&S.Dorn


Waimahaihai stream, stormwater drain at Kupuna Street. Photo S.Dorn

This part of the Waimahaihai stream flows across Kupuna Street in Kihei into a Stormwater drain that flows under Waimahaihai Street toward the ocean.

Read More about the Waimahaihai Wetlands