Hawaii island spent much of Thursday evening and Friday under advisory as heavy rain downed trees, flooded roads and affected water quality in certain areas.

Hawaii County Civil Defense issued an initial severe-weather information message Thursday evening in anticipation of heavy downpours, thunder and lightning. The National Weather Service followed with a flood advisory Friday morning for areas including Waikoloa, Puako, Kawaihae, Kohala, Waimea and Waipio Valley.

The weather service also warned of high surf approaching advisory levels along the shores of North Kohala, Hamakua, Hilo and Puna extending through the weekend. On Friday evening police warned motorists to avoid Bayfront Highway between Pauahi Street and Waianuenue Avenue due to high waves washing debris onto the highway.

Over the 24-hour period ending Friday at 3:45 p.m., the highest rainfall totals were recorded by gauges at Papaikou Well (4.37 inches), Kahua Ranch (3.24), Glenwood (2.63) and Mountain View (2.62).

Route 132 below the Pohoiki Road intersection was closed early Friday morning due to a downed tree and power lines.

Volunteers from the American Red Cross were dispatched to Hawi, where residential flooding was reported.

The state Department of Health’s Clean Water Branch issued a brown-­water advisory for the northern and eastern coasts of the island, including Mahukona Beach Park, due to the heavy rain. The public was warned to stay out of floodwaters and stormwater runoff due to possible contamination from overflowing cesspools and sewers, pesticides, animal fecal mater, dead animals, pathogens, chemicals and other flood debris.

The branch also warned of excessively high levels of the bacteria enterococci at Puako Beach.

The branch advised that “children, the elderly and people with weakened immune systems are the most likely populations to develop illnesses or infections after coming into contact with polluted water, usually while swimming.”

Such swimming-related illnesses — including gastroenteritis, nausea, vomiting, stomachache, diarrhea, headache or fever — are usually not serious and require little or no treatment, the branch noted.

Warning signs were posted at the beach, and the advisory will remain in effect until bacteria levels return to normal.

Forecasters predict that more settled tradewind weather will return Saturday and continue through the coming week.