OCHA said demand for clean water, sanitation and hygiene services has risen sharply due to mass returns of Afghan migrants from neighbouring countries, prolonged drought, disease outbreaks and repeated floods and earthquakes.
A nationwide assessment found that about 85% of households have experienced at least one environmental hazard. The proportion of families needing safe drinking water and sanitation rose from 26 percent in 2024 to 37 percent in 2025, the agency said.
OCHA highlighted a widening gap between urban and rural areas in access to clean water. While infrastructure is improving in cities, rural households face barriers including high costs and long distances to safe water sources.
Female-headed households are among those most in need, and only 41 percent of households with a member with disabilities have access to adequate sanitation, according to the assessment.
Water sources in rural Afghanistan are drying up because of worsening drought, reducing incomes for agriculture-dependent households by 13 percent and increasing their debt levels by 30 percent, OCHA said.
The agency also pointed to cultural restrictions on female staff that have disrupted programme implementation and limited safe access to clean water for vulnerable women and girls.
Many women travel long distances at night to collect water, exposing them to risks, while adolescent girls are dropping out of school due to a lack of sanitation facilities, the report said.
OCHA said the overlap of drought and disease risks has intensified the humanitarian crisis in areas hosting returnees, including Herat, Nangarhar, Nimroz and Khost.
UN assessments show at least 18 Afghan provinces are classified as being at very high risk because of climate vulnerability.
OCHA is seeking $163 million in funding to rehabilitate water systems, support returning migrants, respond to disease outbreaks, prepare for winter and stockpile essential supplies.