Brown Water Advisory Issued for Hilo Bay and Hāmākua Coast

On Jan. 5, 2026, the State Department of Health Clean Water Branch issued a brown-water advisory for Hilo Bay and along the Hāmākua Coast following heavy rainfall and increased stormwater runoff. The advisory cautions that nearshore waters may have degraded clarity and elevated pollutant levels, and it advises recreational ocean users, shellfish harvesters and others to avoid contact with nearshore water until water quality recovers.

The immediate concern is visibility and contamination in coastal areas where runoff concentrates. Degraded clarity can increase hazards for swimmers, snorkelers and boaters by reducing sightlines and masking submerged hazards. Elevated pollutant levels nearshore can pose risks to people who swallow or have prolonged skin contact with the water, and can contaminate shellfish beds, making harvested shellfish unsafe to eat until tests indicate recovery.

Local businesses that depend on ocean recreation and nearshore fishing may see disruptions while the advisory is in place. Tour operators, dive shops and shoreline vendors should anticipate cancellations or reduced demand while residents and visitors avoid affected waters. People who rely on subsistence or commercial shellfish harvesting along the Hāmākua Coast and in Hilo Bay should suspend collection until water quality is confirmed safe.

Stormwater runoff that follows heavy rains often carries sediment, nutrients and urban pollutants from inland to coastal waters, worsening turbidity and delivering contaminants to nearshore ecosystems. These conditions can stress coral reefs, fish and other marine life, compounding the ecological impact beyond immediate human health concerns.

Residents planning to recreate in coastal waters or those who harvest shellfish should heed the advisory and seek updated information before returning to the water. The State Department of Health Clean Water Branch is the official source for status updates and guidance on when conditions have improved and harvesting can safely resume. Checking with the DOH before entering coastal waters will help protect public health and local marine resources as officials monitor water quality and the aftermath of recent storms.