The fire, which burned more than 7,000 acres to the north west of Fort Collins, Colorado.
According to the survey, increased erosion on the burned areas will add sediment to the river, that could add a smoky taste.
Extra purification procedures should be able to handle the lower quality of the water. The city also has the option of adding water from the Horsetooth Reservoir.
It will take around five years for enough growth to take place for the area to be stabilized from erosion.
The Forest Service is also looking into removing expected weeds and burnt trees from the area, especially along hiking trails. Aerial seeding and mulching are also options being considered to speed the recovery of the forest.