The information shown on this map series is subject to change. The volume of water introduced into a regional drainage system from rain and snow melt can vary wildly between different points in the system and from one storm event to another. Ground cover, slope, channel depth, meander, and soil drainage characteristics all play a role, and the accuracy of the flood predictions are in part, limited by the quality of the data and assumptions used in the hydraulic model. For these reasons, the regulations that are derived from flood modeling are often conservative, erring on the side of caution.