Land-based pollution, coursing from Maunalua's ten watersheds, is one of the greatest threats facing
Maunalua Bay.

A watershed is a "basin" area that collects rainfall and drains it into a body of water such as Maunalua Bay.

In a healthy watershed, rainwater soaks into plants, grass and the ground naturally filtering pollutants before reaching the ocean.

Now with our paved surfaces, roofs and concrete drainage channels, rainwater can't seep into the ground.

Instead it flows quickly over our houses, yards and streets into storm drains and directly into Maunalua Bay.

On its way to the Bay, rainwater picks up debris, chemicals, dirt and pollutants - anything left on roads, pavements and driveways.

Each heavy rain pours over 20 tons of sediment and pollutants into Maunalua Bay.

And there is absolutely no treatment
of this polluted runoff.


(Click here to find where your rain water drains into Maunalua Bay)

When we built our communities, little was known about how these drainage systems would affect our ocean.

But now we know polluted runoff harms
plants, fish, animals and people.

Sediment clouds the water, blocks sunlight and makes it hard, if not impossible, for aquatic plants, organisms and coral to survive and grow.

Excess nutrients (from things like fertilizer, detergents, pet waste and green waste) cause excessive algae growth (algae blooms).

When algae die, they decompose in a process that removes oxygen from the water. Fish and other aquatic organisms can't exist in water with low oxygen levels.

Bacteria and other pathogens wash into swimming, fishing, paddling and surfing areas and create health hazards that require beach closures and shutting down of other activities in the Bay.

Debris such as plastic bags, six-pack rings, bottles, and cigarette butts can choke, suffocate, or disable aquatic life such as fish, turtles, seals and birds.

Household hazardous wastes like pesticides, paint, solvents, used motor oil, and other auto fluids can poison aquatic life. On the land, animals and people can become sick from eating diseased fish and shellfish or ingesting polluted water.

We can restore the Bay
by taking care on land.

If Maunalua's 60,000 residents take simple actions in their own backyard we can make a big difference in the Bay. Learn More Take Action

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