[5] The lake's catchment area is large, and includes the eastern slopes of the Remutaka and Tararua Ranges.

The lake today therefore covers an area significantly smaller than its historical size of around 210 km2 (81 sq mi).

[6] The area around the lake is low-lying and swampy, and recent efforts have been made to preserve its important wetland features and restore wildlife habitat that has been degraded through human use.

Agriculture and river development, flood control, and waterway diversions have resulted in the drainage of large areas of the wetlands, reducing their ecological values.

According to other oral histories, explorer Haunui named the wetlands after the way the lake appeared to glisten from the Remutaka Ranges to the west.