The main issues affecting water supply and
sanitation in the US include water scarcity,
pollution, a backlog of investment and concerns
about the affordability of water for the poorest
in its society. Experts say the unpredictability
of rainfall as a result of climate change is
expected to produce more severe droughts and
flooding, with potentially serious consequences
for water supply and pollution from combined
sewer overflows. In particular droughts are
likely to affect the 66% of Americans whose
communities depend on surface water. For
example, drought, as a result of climate change,
is predicted to reduce river flows in the south
western US, potentially affecting the drinking
water supply of large cities such as Las Vegas,
Phoenix and Los Angeles that depend on rivers
for their primary supplies.