19.24.030 - Development standards.
The subdivider shall comply with the following development standards, in addition to those identified in Article 2, Subdivision Standards, and shall incorporate the requirements within the subdivision application.
A. Drainage and Erosion.
1. All necessary erosion control measures shall remain in place until effective stabilization occurs.
2. Erosion control shall utilize live native re-vegetation to the extent reasonably possible.
3. The existing natural drainage system on the property may be used to satisfy the stormwater drainage requirements of this title when recommended by the city manager or designee and approved by the city plan commission based on findings of hydrology and storm drainage report.
4. Ponding areas used as stormwater drainage facilities shall not be permitted, except where recommended by the city manager or designee and approved by the city plan commission. Ponding areas shall remain undisturbed in their natural state to the extent reasonably possible.
5. No existing watercourse or other natural drainage system carrying more than five cubic feet per second in a one hundred year frequency storm, whether on-site or off-site, shall be disturbed by any building development or construction activity within the proposed subdivision unless no other reasonable drainage alternative exists as recommended by the city manager, or designee and approved by the city plan commission.
6. All floodways in floodplain areas shall be dedicated as drainage easements or rights-of-way.
B. Vegetation and Re-vegetation.
1. Vegetation and re-vegetation shall be required on all disturbed areas. If in the course of construction of buildable areas, non-buildable areas are disturbed, the subdivider shall restore the formerly undisturbed areas through the replanting of appropriate native, adaptive and drought tolerant re-vegetation to mitigate soil erosion. For purposes of this requirement, appearance features which are compatible with the area shall be allowed when approved by the city manager or designee.
2. Existing natural vegetation on the property shall be retained in its natural state, except where necessary for the construction of subdivision improvements and buildings or to replace or improve undesirable vegetation.
C. Fire Protection. All lots shall be supplied with adequate fire protection in the form of fire hydrants capable of sustaining a flow rate as follows (as evidenced by flow tests), and spaced at intervals of not more than five hundred feet:
Flow Rates (gallons per minute) | Structures Sprinklered
500 to 999 | All buildings
1,000 to 1,499 | All buildings exceeding three thousand square feet
1,500 or more | None required
A note shall be placed on the subdivision improvement plans which indicates whether or not buildings within the subdivision are required to be sprinklered based on the flow rate requirements of this subsection.
D. Grading, Cuts and Fills. Grading allowed within a subdivision shall be based on the concept of minimal disturbance, and not on maximum buildable footage.
1. Exposed slopes of surfaces of excavation or fill shall comply with the requirements of the geotechnical report, except as otherwise recommended by the city manager, or designee and approved by the city plan commission.
2. The maximum vertical height of a cut or fill shall be fifteen feet, except that the city manager, or designee may recommend and the city plan commission approve a greater vertical height when necessary.
E. Streets.
1. Streets shall not exceed eleven percent grades.
a. Under special site-specific circumstances the eleven percent grades can be exceeded for short distances with the approval of the city manager or designee.
b. Streets with grades in excess of eleven percent shall be permanently signed for no parking.
c. Where a street grade exceeds eleven percent, buildings on lots fronting and accessed by the street shall be required to be sprinklered by the city plan commission when recommended by the city manager, or designee and the fire chief.
d. If the only access to a subdivision is by a street with a grade exceeding eleven percent, then all structures in the subdivision are considered to be accessed by a street exceeding eleven percent and required to be sprinklered. A note shall be placed on the subdivision improvement plans which indicates whether or not buildings within the subdivision are required to be sprinklered based on the requirements of this subsection.
2. Mountain residential and divided mountain residential streets shall be designed to meet a design speed as follows:
a. Twenty miles per hour when the street is designed to carry an average daily traffic (ADT) volume of less than two hundred vehicle trips;
b. Twenty-five miles per hour when the street is designed to carry an average daily traffic (ADT) volume of two hundred or more vehicle trips;
c. Twenty-five miles per hour when the street is designed as a stub street.
3. Mountain Residential Street. A mountain residential street is intended to reduce roadway impact to environmentally sensitive areas and to protect landscape and topography, and shall only be used for development of property within the mountain development area.
a. The mountain residential street carries residential neighborhood traffic, and provides direct access to abutting properties. This street shall carry traffic from within the neighborhood and shall provide the safest environment.
b. Mountain residential streets shall be designed to discourage through traffic unless connection to streets outside the subdivision is recommended by the city manager or designee.
c. The total right-of-way width for a mountain residential street shall be twenty-three feet; which shall include the following:
i. Two ten-foot driving lanes;
ii. Header curbing;
iii. No sidewalks;
iv. No parkways;
v. Utility easements; as needed within the subdivision to accommodate utility service connections.
d. On-street parking shall be prohibited. Designated parking areas may be provided on property adjacent to the street right-of-way.
4. Divided Mountain Residential Street. A divided mountain residential street is intended to reduce roadway impact to environmentally sensitive areas and to protect landscape and topography, and shall only be used for development of property within the mountain development area.
a. The divided mountain residential street carries residential neighborhood traffic, and provides direct access to abutting properties. This street shall carry traffic from within the neighborhood and shall provide the safest environment.
b. Divided mountain residential streets shall be designed to discourage through traffic unless connection to streets outside the subdivision is recommended by the traffic engineer.
c. The total right-of-way width for a divided mountain residential street shall vary based on the width of the median, but shall include as a minimum of the following:
i. Two ten-foot driving lanes;
ii. Header curbing;
iii. One median of variable width with header curbing;
iv. No sidewalks;
v. No parkways;
vi. Utility easements; shall be provided as needed within the subdivision to accommodate utility service connections.
d. On-street parking shall be prohibited. Designated parking areas may be provided on property adjacent to the street right-of-way.
F. Streetlighting. The subdivider shall furnish and install one streetlight at each street intersection. The design and installation of streetlights shall be in accordance with the development standards for construction.
G. Panhandle Lots for Residential Uses. Panhandle lots for residential uses shall be permitted to reduce grading and cut and fill. The maximum length of the panhandle shall be seven hundred fifty feet. The minimum width of the panhandle shall be twelve feet to serve one dwelling unit. A maximum of four dwelling units may jointly use a panhandle, provided that the minimum cumulative width of the entire common driveway is twenty feet. Maintenance of the common driveway, in cases of joint use, shall be ensured by deed restrictions and a note of such deed restrictions shall be placed on the face of the plat. Residential lots with panhandles in excess of one hundred feet will be required to provide residential sprinkler systems and hard wired alarm system on structures. A note shall be added to the recording plat and the subdivision improvement plans indicating whether buildings are required to be sprinklered and have hard wired alarm systems within the subdivision, and which lot numbers have such requirement.
H. Signage. Traffic control signs shall be permitted to be installed on shared sign posts to reduce visual clutter in the subdivision.
I. Driveway Access.
1. The city plan commission may approve a driveway length in excess of two hundred fifty feet, and up to a maximum of seven hundred fifty feet, when the subdivider provides evidence of all of the following:
a. A driveway grade at a maximum horizontal distance in feet is provided as follows:
Driveway Grade | Maximum Grade Length (horizontal distance in feet)
12—13 | 700
14—15 | 350
16—18 | 200
Where a driveway grade exceeds eleven percent, buildings on lots fronting the driveway shall be required to be sprinklered by the city plan commission when recommended by the city manager or designee and the fire chief. A note shall be placed on the subdivision improvement plans which indicates whether or not buildings within the subdivision are required to be sprinklered based on the requirements of this subsection; and
b. The driveway is of asphalt or concrete construction to support firefighting and other emergency apparatus.
2. For purposes of this subsection, the driveway length shall be calculated from the abutting street to the nearest face of the primary structure.
3. The city plan commission may grant an exception when it makes a finding pursuant to Chapter 19.48 and allow a greater driveway length than seven hundred fifty feet, the approval shall be subject to the building construction being sprinklered with a hard wired alarm system. A note shall be added to the recording plat and the subdivision improvement plans indicating whether buildings are required to be sprinklered and have hard wired alarm systems within the subdivision, and which lot numbers have such requirement.
(Ord. 16882 § 2 (part), 2008) (Ord. No. 17236, § 27, 11-10-2009; Ord. No. 17396, § 19, 8-24-2010)
