Purpose

What is an ʻauwai?

‘Auwai are open channels of water also called irrigation ditches. They connect to a stream or spring. The ‘auwai funnels water from a water source, like the stream or spring, into lo‘i kalo (taro ponds) and sometimes loko i‘a (fishponds). They are sometimes lined with stones or dirt. 

Why are they built?

Wetland kalo must have a continuous source of freshwater. The ‘auwai helps provide a constant supply of cool freshwater, without 24-hour bucket-carrying shifts.

How do you get the water from the stream into the ‘auwai? You can try coaxing it with ‘awa or promises of a year’s supply of kūlolo. But a more foolproof method is to build a small dam called a māno wai. Rocks are carefully stacked together across the stream to form the māno wai. This controls the water flow and diverts some of the stream water into the ‘auwai. The māno wai is loosely constructed to let water pass through and over the ‘auwai system. During times of great flooding, the māno wai usually falls apart, but that is a good thing. That way, the māno wai protects the lo‘i from flooding and saves the farmer’s crops.

When the farmer wants to increase water flow in his lo‘i, he adds a few rocks to the māno wai. This increases water pressure at the māno wai. It forces stream water to divert to the farmer’s lo‘i. When the farmer’s lo‘i is well fed, he decreases water flow. He removes a few stones from the māno wai to redirect water back into the stream. 

How does the ʻauwai help control flooding and erosion?

‘Auwai are generally built at a gradual slope. A 10% slope helps the water move gently over the bottom of the ‘auwai. A steeper slope would increase the speed of the water and could cause flooding. The gentler slope keeps water from cutting into the sides of the ‘auwai, which could cause erosion. Lining the bottom and the sides of the ‘auwai with rocks also helps control erosion.

Large ‘auwai were named after the chief who directed the construction of it. In Nu‘uanu on the island of O‘ahu, the Pākī ‘auwai extended half way down the ahupua‘a. It took 700 men to build it. The work was completed in just three days!

Who uses and maintains the ʻauwai?

The ‘auwai was used and maintained by the families that lived in the ahupua‘a. The konohiki called people together to build and clean the ‘auwai. Farmers were able to use water from the ‘auwai to irrigate their lo‘i kalo. But their water use depended on how many of their family members helped to mālama (care for) the ditch system.

No one owned water. Wai is a link to our akua. Akua related to water include the major gods Kāne and Lono, and local water gods or goddesses. Wai was a community resource to be shared by everyone. Farmers took as much water as they needed. Then they would close off the water inlet so the next farmer below could receive his share. Only half the amount of water flowing in the stream could be used for farming. This was a law that was enforced by the konohiki and the people too. And the water that did go into the lo‘i kalo was returned to the stream at the end of the lo‘i.

Sometimes the konohiki would call together kānaka to clear and repair ‘auwai. ‘Ohana who did not help would not receive water for their lo‘i.

Very few farmers ignored the konohiki’s order. They knew that their fields would not produce kalo without water. They also knew that the konohiki could remove them from the land at anytime if they were unproductive.

Today we have a Commission of Water Resource Management. The seven-member commission has a lot of kuleana over our most important resource—wai. Similar to the konohiki of old, they are charged with protecting water and people’s rights to it.