How do post-fire flood events affect water quality?

Runoff from burned areas can alter water quality in multiple ways for the first few years after wildfire up to a decade. Common changes include larger amounts of nutrients like nitrates and sulfates, altered pH, larger amounts of total dissolved solids, increased turbidity, and more organic carbon. Additionally, sediment transport may increase up to 20 times with debris entering reservoirs and lakes that are relied on for drinking water. Together these impacts may affect the color, taste, odor, and treatability of municipal water supplies. Furthermore, regardless of treatments applied to burned watersheds, ash tends to run into stream channels, reducing water quality and potentially obstructing or damaging water treatment facilities.