A yearlong standoff between Israel and Hamas has left the territory's sewage system in a state of collapse, flooding its coastal waters with human waste and blanketing crowded beachside neighborhoods in a fierce stench.

The consequences can be deadly. Last year, five people were killed when a small waste reservoir collapsed. This summer, as Gazans head to the beaches, the World Health Organization is warning them to stay out of the sea.

"If the amount of sewage dumped into the sea remains at this rate, we'll be facing a dark future for seawater in Gaza," said the WHO's Mahmoud Daher.

An Israeli blockade imposed after Hamas violently wrested control of Gaza last year has left the territory without enough fuel to operate its already overburdened treatment plants. Palestinian militant attacks from Gaza into Israel have deterred Western donors from building new facilities.

Now there's a glimmer of hope.

A cease-fire that went into effect June 19 could lead to a resumption of normal fuel supplies. Little has changed on the ground so far, in part because Israel has repeatedly reclosed the border crossings in response to continued rocket fire. But Palestinians think critical projects can be quickly finished if the truce takes root.

The sewage problems are not new. Throughout decades of Egyptian, Israeli and Palestinian rule, the Gaza Strip has been piping sewage into its 25 miles of sea.

But the fuel shortages mean treatment plants work only intermittently, and since January, an additional 10 million gallons a day of partially treated sewage have been fouling the sea.