“The Water and Sanitation System in the Gaza Strip, an assessment”.
Gaza’s water conditions have always been critical because of geographic reasons; the area lacks access to conspicuous surface water and is therefore fully dependent on groundwater and rainwater harvest. However, the aquifer beneath the Gaza Strip proves to be an insufficient source of fresh water to the 1.5 million inhabitants living enclosed in mere 365 square kilometers.  As a result, the aquifer was continuously overdrawn and as the water level dropped, saline water from the Mediterranean found its way through. This salt intrusion is responsible for the serious degradation of the aquifer’s water quality.  By 2000, 90 percent of the drinking water, provided by the Coastal Aquifer, was found unfit for human consumption.
The situation deteriorated as Israel imposed a closure of the Gaza Strip in October 2007. The Israeli authorities severely restricted the import of fuel, necessary to supply Gaza’s only power plant. In addition, they obstructed the import of materials such as cement and pipelines and spare parts necessary for technical repairs.  In March 2008, Gaza’s electricity company (GEDCO), made an orderly request for spare parts to Israel. The order was paid full but 8 months later, the parts were still stuck in Ashdod Port and Karni Crossing because Israel refused to allow them into Gaza.  Due to the lack of stable electricity supply, water pumps failed to operate and sewage could not longer be treated (full sewage treatments requires 14 continuous days of uninterrupted power supply).  As a consequence the Gaza Coastal Municipal Water Utility (CMWU) has been unable to deliver potable water (unfiltered tap water was saline and undrinkable throughout the Gaza Strip) and, as of January 2008, 50 to 60 million liters of partially treated or untreated sewage has flowed daily into the Mediterranean.   The sewage discharge contaminates Gaza sea waters and poses serious health risks to the population of the Gaza Strip. Also, the sewage flows northward to Israeli coasts, where it can affect the nearby Ashkelon desalination plant.
 The restrictions imposed by Israel throughout the past year were a clear violation of international humanitarian law which states that Israel, as the occupying power, is obliged to facilitate access to all amenities. Under the Geneva Conventions, the occupying power is “responsible for infrastructure maintenance, using the taxes it collects from the local inhabitants”. But by August 2008, the Palestinian Water Authority (PWA) stated 40 percent of the Gazans had no running water at all.
Following the Israeli bombardments of the Gaza Strip since December 27, over 75 percent of Gaza’s electricity has been cut off. Hospitals, including Gaza’s main Shifa Hospital, are struggling to function under 24-hour per day power outages.  They work mainly on back-up generators. Gaza City’s local power plant shut down December 30.  No fuel was allowed into Gaza until January 11, when UNRWA was able to deliver fuel to municipalities in Jabalia, the Middle Area and southern Gaza for solid waste collection.  On January 4th the Israel-based Legal Center for Freedom of Movement (GISHA) reported about the water and sanitation situation and quoting Maher Najjar, Deputy Director of Gaza’s water utility who warned that “the water and sewage system was collapsing, cutting thousands of people off from water supply and causing sewage flood the streets”. 
A couple of days later, on January 7, the World Bank published a fact sheet on the matter, based on data collected by the Gaza Coastal Municipal Water Utility (CMWU) and the Palestinian Water Authority (PWA). The report affirms that nearly all sewage and water pumps are out of operation due to lack of electricity. As a consequence nearly the entire Gaza population is left without running water. Together with the disruption of Gaza’s sewage treatment plants and the continuous sewage overflow in urban areas the current situation implies tremendous risks to public health. There is also concern that the Beit Lahiya sewage lagoon, which broke already in March 2007, will break again as the level is rising by two centimeters a day. If it breaks, either by overflow or by the explosion of bombs, it would put 10.000 people in the surroundings in immediate danger of drowning. On January 10, the Gaza City Wastewater Treatment Plant has been reported damaged and 200.000 liters of wastewater has been said to have leaked into the environment.  The Palestinian Hydrology Group (PHG) is currently trying to get 20.000 liters of potable water into the Gaza Strip but is facing the same hinder to enter Gaza as other humanitarian organizations, only a minimum of aid is allowed through by the Israeli authorities.
Since January 18 the CMWU is working to assess and repair damage on the water and sanitation network in the Gaza Strip. It has been estimated that approximately 50% of the watsan infrastructure has been destroyed.  The Gaza power plant is still only working partially due to shortage of industrial fuel.

References :
Gray Alice, “Title”, Maan News Agency, January 8, 2009. (CHECK TITLE)
The Legal Center for Freedom of Movement (GISHA), “Following prevention of fuel supplies, destruction of electricity lines: Gaza electricity, water and sewage systems on verge of collapse”, January 4, 2009.
United Nations Office for the Coordination of Humanitarian Affairs (OCHA), “Field Update on Gaza from the Humanitarian Coordinator”, 17 PM, January 12, 2009.
United Nations Office for the Coordination of Humanitarian Affairs (OCHA), “OPT: Gaza Humanitarian Situation Report, Impact of fuel shortages on Gaza sanitation-Polluting the sea”, April 29, 2008. (CHECK SOURCE)
World Bank, “Fact Sheet: Gaza Strip Water and Sanitation Situation”, January 7, 2009.