1. Existing legal uses of property or the right to continuation of such legal use. However, if a nonconforming use of land or a building or structure is discontinued for 12 months, or destroyed to the extent of 50 percent of its value as determined by a competent appraiser, any further use must comply with this article and regulations of the City of Phoenix;

2. Reasonable repair or alteration of property for the purposes for which the property was legally used on August 3, 1984, or any regulation affecting such property takes effect, except that any alteration, addition or repair to a nonconforming building or structure which would result in increasing its flood damage potential by 50 percent or more must be either floodproofed or elevated to or above the regulatory flood elevation;

3. Reasonable repair of structures constructed with the written authorization required by Section 48-3613, Arizona Revised Statutes; and

4. Facilities constructed or installed pursuant to a certificate of environmental compatibility issued pursuant to Title 40, Chapter 2, Article 6.2, Arizona Revised Statutes.

1. The construction of bridges, culverts, dikes and other structures necessary to the construction of public highways, roads and streets intersecting or crossing a watercourse;

2. The construction of storage dams for watering livestock or wildlife, structures on banks of a watercourse to prevent erosion of or damage to adjoining land if the structure will not divert, retard or obstruct the natural channel of the watercourse or dams for the conservation of floodwaters as permitted by Title 45, Chapter 6, Arizona Revised Statutes;

3. Construction of tailing dams and waste disposal areas for use in connection with mining and metallurgical operations. This subsection does not exempt those sand and gravel operations that will divert, retard or obstruct the flow of waters in any watercourse from complying with and acquiring authorization from the Floodplain Board pursuant to regulations adopted by the Floodplain Board under this article;

4. Other construction upon determination by the Floodplain Board that written authorization is unnecessary;

5. Any flood control district, county, city, town or other body from exercising powers granted to it under Title 48, Chapter 21, Article 1, Arizona Revised Statutes;

6. The construction of streams, waterways, lakes and other auxiliary facilities in conjunction with development of public parks and recreation facilities by a public agency or city; and

7. The construction and erection of poles, towers, foundations, support structures, guy wires and other facilities related to power transmission as constructed by any utility whether a public service corporation or a city.