Makiki / Lower Punchbowl / Tantalus Water Hardness & Quality Report (2026)

Makiki–Lower Punchbowl–Tantalus, Honolulu, Hawaii — a major central Honolulu neighborhood complex (Makiki–Lower Punchbowl–Tantalus is a distinctive central Honolulu neighborhood area on the lower slopes of the Koolau Range, including the Punchbowl Crater area (the extinct volcanic crater that is home to the National Memorial Cemetery of the Pacific — the famous 'Punchbowl' cemetery where over 34,000 veterans including ernie Pyle are interred) and the Tantalus–Round Top Drive scenic road (one of the most beautiful drives in Honolulu — the Tantalus Drive winds through a lush rainforest of bamboo, hala, and introduced tropical plants on the upper Punchbowl crater rim)), a diverse Honolulu County community with a significant Japanese-American, Chinese-American, Native Hawaiian, and professional population (the Makiki–Punchbowl area is one of Honolulu's most ethnically diverse and economically mixed urban neighborhoods), adjacent to the University of Hawaii at Manoa, and one of the most scenic urban neighborhoods in Hawaii — draws its municipal water supply via the Honolulu BWS. Water hardness in Makiki–Punchbowl–Tantalus measures 14.5 mg/L — classified as very soft.

Makiki–Punchbowl–Tantalus's very soft supply reflects the Oahu Koolau Basalt aquifer's calcareous-poor volcanic character. The Koolau Range aquifer at Honolulu provides water from the Quaternary Koolau Shield Volcano Basalt (calcareous-poor — volcanic basalt with minimal dissolved carbonates). Honolulu BWS applies excellent treatment, producing the very soft 14.5 mg/L.

With hardness at 14.5 mg/L, Makiki–Punchbowl–Tantalus residents enjoy very soft water. Honolulu BWS consistently delivers water meeting all Hawaii DOH and EPA Safe Drinking Water Act requirements.