A. Intent and purpose. The sensitive lands within the city are superimposed as an overlay with respect to lands classified for various uses and purposes and is intended to give recognition to the need to protect the public health, safety and welfare of the community through regulation and control of the lands within the sensitive lands areas to thereby mitigate potential financial burdens arising from flood damage loss, to preserve natural drainage ways, or on steep slopes from encroaching uses which threaten to adversely affect the property rights of citizens of the community, personal safety and the public health by unnatural conditions arising from upstream or downstream flood levels.
The sensitive lands areas has for its purpose the preservation of natural water storage areas, steep slopes or eroding soils by discouraging or prohibiting incompatible uses except in those instances where a finding may properly be made by the planning commission pursuant to this section.
B. Definitions. In this section the following words and phrases shall be construed to have the specific meanings assigned to them as follows:
Drainageways: means those areas which convey significant seasonal concentrations of water over the surface of the land;
Excavation: means mechanical removal of earth material;
Fill: means any act by which earth, sand gravel, rock or any other similar material is deposited, placed, pulled or transported, and includes the conditions resulting therefrom;
Flood: means a temporary rise in stream flow or stage that results in water overtopping stream banks and inundating land adjacent to the normal flow of water through the stream channel;
Flood hazard: means a danger to property or health as a result of inundation of the floodplain;
Floodplain: means the relatively flat area or lowlands adjoining the channel of a river, stream, water course or other body of water which has been or may be covered by flood waters within the area of applicability defined by the floodplain district;
Grading: means any excavation or filling or combination thereof;
Obstruction: means any dam, wall, embankment, levee, dike, pile, abutment, projection, excavation, channel modification, bridge, conduit, culvert, building, gravel, refuse, fill, structure, matter or things of a similar nature in, along, or across or projecting into any channel, watercourse, or floodplain drainageway areas which may impede, retard or change the direction of the flow of water, either by itself or that is placed where the flow of water might carry the same downstream to the damage of health or property;
Regulatory flood: means the flood used to define the outer boundary lines of the floodplain area. The maximum flood predicted to occur within 100 years;
Steeply sloping lands: means portions of the ground surface which have a slope of 13 percent or greater;
Structure: means constructed edifice, barrier or building of any kind, or any artificial build-up or composition of physical parts adjoined together.
C. Permitted uses. The following uses by their nature do not threaten substantial obstruction of water flow in the floodplain and do not impair the water storage capacity of the floodplain and shall be permitted within the sensitive lands areas subject to the limitations in this section stated:
1. Off-street parking and maneuvering areas, access ways and service drives located on the ground surface. Excavation, grading and paving may occur to construct said facilities; however, no fill shall be allowed for construction of said facilities other than gravel for a paving base and only an amount of gravel commensurate with city construction standards for said facilities shall be allowed;
2. Accessory residential uses such as lawns, gardens or planting areas not causing substantial obstructions to flood waters and including fences designed to minimize the obstruction of flood waters and flood-carried debris;
3. Roadways, bridges or utility structures designed to not significantly impede the flow of flood waters;
4. Agricultural uses conducted without locating a structure in the sensitive lands including a boundary fence designed to minimize the obstruction of flood waters and flood-carried debris;
5. Recreational uses such as bicycle and pedestrian paths, archery range, athletic field or parks. The recreational use shall not include any permanent structures causing a significant obstruction to the flow of flood waters;
6. Public and private conservation areas for the conservation of water, soil, open space, or wildlife resources.
D. Prohibited uses and activities. The following uses and activities are prohibited within the sensitive lands except pursuant to special permit granted by the planning commission based on findings as by this section:
1. filling;
2. permanent structures permitted in other zoned areas of the city;
3. any temporary structure which by its nature cannot be readily removed from the floodplain area during periods of flooding and which would significantly impede or interfere with the flow of flood waters within the district;
4. Any change in the topography or terrain which would have a substantial tendency to change the flow of waters during flooding period or which would increase flood hazard or alter the direction or velocity of the flood water flow or would be subject to destruction due to seismic activity or land slides;
5. Subsurface sewerage disposal septic tanks and drain fields.
E. Nonconforming uses. Any pre-existing condition or structure within the sensitive lands area is subject to the provisions of this code.
F. Special permits or exceptions. In accordance with the procedures and requirements set forth in § 13.06.180 of this code, an application for a special use permit filed as by said section stated may be considered or denied by the planning commission based on written findings in conformity with the requirements of this zone ordinance.
An application for special permit in form prescribed by the planning department of the city shall be supported by the following additional data or information to enable the planning commission to adequately determine whether the proposed use is located in the sensitive lands area and if so, whether the proposal, if granted, will conform to the purposes and guidelines as set forth in this section.
1. Plans drawn to scale, submitted in triplicate as prepared by a registered professional engineer with experience in hydraulic and hydrologic principles and processes showing the nature, location, dimensions, elevations and topography of the site; the location of existing and proposed structures located upon the site, existing and proposed fill areas, and the relationship of these to the location of the stream channel;
2. Any documentation, photographs, water marks, and similar evidence offered in support of the claim that the site or area in question lies above high water as defined by the regulatory flood;
3. If it is determined by the planning commission that the proposed use is within the sensitive lands area as herein defined, the applicant shall furnish such further information, data and evidence as may be reasonably available to support the granting of the petition in accordance with the following guidelines, in the absence of which said petition shall be denied by the planning commission:
a. Proposed improvements will not have a serious tendency to change the terrain during future use such as to cause a compounding of flood hazards or destruction of property to thereby seriously interfere with the intent and purposes of the regulations.
b. No structure, fill, storage or other uses shall be permitted which alone or in combination with existing or future uses would materially reduce the capacity of the flood-plain area or sensitive land areas to create a present or foreseeable hazard to the public health, safety and general welfare.
The city shall reserve the right to retain a registered professional engineer with experience in hydraulic principles and processes for the purpose of reviewing evidence submitted in support of any application for special use permits pursuant to this section.
G. Standards for permitted structures. Any structure or additions to existing structures permitted within the sensitive lands area pursuant to this section shall comply with the following standards:
1. Permitted structures, such as electrical and service equipment, etc., shall be constructed at or above the regulatory flood protection elevation. Utility openings shall be sealed and locked.
2. The lowest floor elevation of a structure designed for human occupancy shall be at least one and one-half feet above the flood surface elevation.
3. The lower portions of any structure shall be flood- proofed or otherwise protected from significant damage by inundation to a minimum flood surface elevation one and one-half feet above the surface elevation of the regulatory flood.
4. The design of substructures and structural members of all buildings shall be designed to withstand expected water pressures and velocities as well as minimize flood risk conditions.
H. Appeal to city council. An appeal from any decision of the planning commission may be filed with the city clerk for hearing by the city council as provided by § 13.06.030.
I. Construction time period, extension. If substantial construction or development has not taken place within one year from the date of approval of the general development plan and program, the planning commission shall review the district at a public hearing to determine whether or not its continuation in whole or in part is in the public interest, and if found not to be, shall recommend to the city council that the permit of approval on the property be removed. The city council, at the request of the applicant, may grant an extension of time if justifiable.
(Ord. 81-09 (part), 1981)