On Oʻahu, the Waikīkī and Ala Moana areas are especially vulnerable to coastal erosion and flooding linked to sea level rise. That’s because they were once wetlands, ponds and waterways — until they were drained for the Ala Wai Canal. Our partners at the UH Mānoa Center for Oral History have some firsthand memories — introduced by ethnic studies professor Ty Kāwika Tengan.