The following development guidelines are applicable to hazards identified above and in the State Department of Geology and Mineral Industries, Bulletin 78, Environmental Hazard Inventory, Clackamas County, Oregon. The above documents and mapping are referenced and adopted as part of the comprehensive plan and available in the office of the city recorder.
A. Purpose. Various geological formations in the city have different characteristics with respect to suitability for development because of landslide potential, high groundwater, and soil characteristics. The following development guidelines have been prepared in order that geological hazards will be recognized and the losses resulting therefrom will be lessened.
B. Areas of Concern. The primary areas of concern are active and potential landslides, high groundwater, weak foundation soils, and steep slopes.
C. Considerations. The most important consideration with respect to natural hazard factors are:
1. That development approved is not hazardous to buildings, structures or the inhabitants thereof;
2. That protection to unsuspecting purchasers of property having natural hazards is provided;
3. That unjustified expenditure of public funds or losses incurred due to natural hazards resulting in damage to development which should not have been approved initially, is prevented.
D. Standards. The following shall be required in hazard areas as identified:
1. Geologically recent landslide areas: a site specified geotechnical analysis by a qualified professional geologist or engineering geologist including all property outside of known or suspected hazard that is within one hundred (100) feet.
2. Weak Foundation Soils. In areas known to have weak foundation soils for construction of buildings and roads, a detailed soils analysis shall be made by a qualified soils expert. The analysis shall include a recommendation to overcome identified limitations prior to development approval.
3. Slopes Greater than Thirty-Three (33) Percent. A site specified geotechnical analysis by a qualified professional geologist or engineering geologist will be required.
E. Procedure. When a geotechnical analysis or soils analysis is required, the following procedure shall be followed in determining the suitability and desirability of development proposed in areas having geological hazards:
1. Requesters of development approval within hazard areas shall be required to submit a statement as to how such hazards have been recognized in the proposal. Such statement shall be required to include the following:
a. The cause, the extent and the potential of the hazards;
b. The provisions proposed to overcome the hazards;
c. A certified declaration as to the on-going responsibility of the developer should such hazards be of a nature whereby possible future danger may exist. Such declaration should include the developer’s intent to continue or absolve responsibility should the development be sold;
d. Additional material as determined to be desirable to make a determination as to the acceptability of the statement;
e. The name and professional stamp of that person or persons determining the causes, extent and potential of the hazards as well as the provisions proposed to overcome the hazards. (Prior code § 10.705)