Hurricane rain is not just unadulterated distilled water. It can often contain chemicals similar to acid rain yet also churn up undrinkable salt water from the ocean that causes corrosive damage. This water essentially has a negative impact on any source of drinking water it touches. This is particularly noticeable in rural areas where high volumes of run-off from fields containing fertilizers and other chemicals can quickly contaminate karsts and private wells.
In more populated ares, polluted floodwater is typically an even bigger concern as it mixes and contaminates the water supplies of municipal water systems. Damage to municipal water pipes is often a part of storm destruction, and this means that safe drinking water is unable to get to homes and individuals on that pipeline for days, weeks, and sometimes months.