A. Statutory Authority: The legislature of the State of Idaho pursuant to Idaho Code 46-1020 through 46-1024, authorized local government units to adopt a floodplain map and floodplain management ordinance that identify floodplains and minimum floodplain development standards to minimize flood hazards and protect human life, health, and property. Therefore, the Board of County Commissioners of Payette County, Idaho does hereby ordain as follows.
B. Findings Of Fact:
1. The flood hazard areas of Payette County are subject to periodic inundation which adversely affects the public health, safety, and general welfare that results in:
a. Loss of life and property;
b. Health and safety hazards;
c. Disruption of commerce and governmental services;
d. Extraordinary public expenditures for flood relief and protection; and
e. Impairment of the tax base.
2. These flood losses are caused by natural forces and structures in the flood hazard areas, which are inadequately elevated, flood-proofed, or otherwise unprotected from flood damages, and by the cumulative effect of obstructions in floodplains causing increases in flood heights and velocities.
3. Local government units have the primary responsibility for planning, adopting, and enforcing land use regulations to accomplish proper floodplain management.
4. Flooding is aggravated by the collection of debris upstream of the many channel obstructions located in the floodplain areas. Such obstructions include bridges, fences, houses, trees, etc. The accumulation of debris has resulted in significantly higher water surface elevations upstream from the obstructions than would otherwise be expected. Obstructions can and tend to cause flooding to extend beyond anticipated FEMA 100-year flood boundaries at points of debris accumulation which cannot be predicted.
5. All structures located roughly within the limits of the 500-year floodplain are subject to inundation, if not directly impacted by the channel itself, during floods of return frequencies of ten (10) to twenty (20) years. This is due to the tendency of the channel to change abruptly, during high water periods, because of the river's characteristics.
6. The levees built by private property owners may be considered by FEMA to be inadequately designed or deteriorated such that they cannot be classified as permanent structures capable of withstanding a 100-year flood; and, therefore, may result in higher risk and be included in the area of special flood hazard.
7. Encroachments (i.e., houses, fill, etc.) on floodplains reduce the flood carrying capacity and increase flood heights, thus increasing flood hazards beyond the encroachment. With every new structure or other development since the FEMA 100-year flood boundary was determined, the ability of the floodplain to function changes.
8. The Payette and Snake Rivers and their tributaries and floodplains in Payette County are essential to the well being of its citizens as a source of recreation, fish and wildlife habitat, aesthetic beauty, and a source of irrigation water as well as other economic and lifestyle values.
9. Development adjacent to waterways has had a direct effect on the natural stream by destroying or greatly altering fish and wildlife habitat and by unnaturally armoring the banks of the waterways to prevent erosion and damage riparian areas thus resulting in increased risk to manmade structures.
C. Statement Of Purpose: The purpose of this chapter is to promote public health, safety, and general welfare and to minimize public and private losses due to flood conditions in specific areas by provisions designed to:
1. Protect human life, health and property;
2. Minimize damage to public facilities and utilities such as water purification and sewage treatment plants, water and gas mains, electric, telephone and sewer lines, streets and bridges located in floodplains;
3. Help maintain a stable tax base by providing for the sound use and development of flood prone areas;
4. Minimize expenditure of public money for costly flood control projects;
5. Minimize the need for rescue and emergency services associated with flooding and generally undertaken at the expense of the general public;
6. Minimize prolonged business interruptions;
7. Ensure those who occupy the areas of special flood hazard assume responsibility for their actions;
8. Through the building permit process require those who occupy the areas of special flood hazard to assume responsibility for their flood risk.
D. Objectives And Methods Of Reducing Flood Losses: In order to accomplish its purpose, this chapter includes methods and provisions to:
1. Require that development that is vulnerable to floods, including structures and facilities necessary for the general health, safety and welfare of citizens, be protected against flood damage at the time of initial construction;
2. Restrict or prohibit uses which are dangerous to health, safety and property due to water or erosion hazards, or which increase flood heights, velocities, or erosion;
3. Control filling, grading, dredging and other development which may increase flood damage or erosion;
4. Prevent or regulate the construction of flood barriers that will unnaturally divert floodwaters or that may increase flood hazards to other lands;
5. Preserve and restore natural floodplains, stream channels, and natural protective barriers which carry and store floodwaters. (Ord. 2017-4, 6-28-2017)