Chapter 16.28
DESIGN STANDARDS
Sections:
16.28.010 Principles of acceptability.
16.28.050 Grading of building sites.
16.28.070 Large lot subdivision.
16.28.080 Land for public purposes.
16.28.100 Improvement requirements.
16.28.010 Principles of acceptability.
A land division, whether by a subdivision, creation of a street, or a partitioning, shall conform to any development plans, shall take into consideration any preliminary plans made in anticipation of any development, and shall conform to the design standards established by this title. [Ord. 9-91 § 1 (Exh. A § 24), 1990; Ord. 9-57 § 1 (Exh. A § 25), 1981].
16.28.020 Streets.
A. General. The location, width and grade of streets shall be considered in their relation to existing and planned streets, to topographical conditions, to public convenience and safety, and to the proposed use of land to be served by the streets. The street system with intersection angles, grades, tangents and curves shall be appropriate for the traffic to be carried considering the terrain. Where location is not shown in a development plan, the arrangement of streets shall either:
1. Provide for the continuation or appropriate projection of existing principal streets in surrounding areas; or
2. Conform to a plan for the neighborhood approved or adopted by the planning commission to meet a particular situation where topographical or other conditions make continuance or conformance to existing streets impractical.
B. Minimum Right-of-Way, Roadway Width and Setbacks. Unless otherwise indicated and approved on a development plan, the right-of-way widths, paving widths, setbacks of buildings from the right-of-way, and width and number of sidewalks shall not be less than the minimum shown on the following table:
|
Type of Facility |
Minimum Right-of-Way |
Minimum Paving Width |
Minimum Building Setbacks |
Minimum Sidewalk Requirements |
|---|---|---|---|---|
|
Major Arterials |
60 – 100 feet |
2 – 24 feet |
25 feet |
5 feet on 2 sides |
|
Minor Arterials |
60 – 80 feet |
2 – 24 feet |
20 feet |
5 feet on 2 sides |
|
Light Industrial Streets or Loop Roads |
60 feet |
1 – 48 feet |
20 feet |
None |
|
Collector Streets |
60 feet |
1 – 40 feet |
Per zoning ordinance (EPMC Title 17) |
5 feet on 2 sides |
|
Local Streets: |
||||
|
“A” Type |
60 feet |
1 – 36 feet |
20 feet |
5 feet on 2 sides |
|
“B” Type |
50 feet |
1 – 36 feet |
20 feet |
5 feet on 2 sides |
|
Minor Streets or Neighborhood Streets: |
||||
|
“A” Type |
50 feet |
1 – 28 feet |
Per zoning ordinance (EPMC Title 17) |
5 feet on 1 side |
|
“B” Type |
40 feet |
1 – 24 feet |
Per zoning ordinance (EPMC Title 17) |
5 feet on 1 side |
|
Cul-de-Sacs: |
||||
|
“A” Type |
60-foot radius |
50-foot radius |
Per zoning ordinance (EPMC Title 17) |
5 feet all around |
|
“B” Type |
50-foot radius |
32-foot radius |
Per zoning ordinance (EPMC Title 17) |
5 feet all around |
|
Bike Paths: |
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|
Alleys |
20 feet |
8 feet |
10 feet |
N/A |
|
Street |
8 feet |
8 feet |
Per zoning ordinance (EPMC Title 17) |
N/A |
|
Parkway |
8 feet |
8 feet |
Per zoning ordinance (EPMC Title 17) |
N/A |
|
Drainage Areas |
10 feet |
10 feet |
Per zoning ordinance (EPMC Title 17) |
N/A |
|
Special Streets: |
||||
|
Loto-Nova-Napa Street |
60 feet |
1 – 44 feet |
Per zoning ordinance (EPMC Title 17) |
5 feet on 2 sides |
|
Platt Avenue – North/South |
60 feet |
1 – 44 feet |
Per zoning ordinance (EPMC Title 17) |
5 feet on 1 side 8 feet on 1 side |
C. Reserve Strips. Reserve strips or street plugs controlling the access to public ways will not be approved unless such strips are necessary for the protection of the public welfare or of property rights or both, and in no case unless the control and disposal of the land composing such strips is placed definitely within the jurisdiction of the city under conditions approved by the planning commission.
D. Alignment. All streets, other than minor streets or cul-de-sacs, shall, as far as practical, be in alignment with existing streets by continuation of the center lines thereof. In no case shall the staggering of streets making “T” intersections be so designed that a jog is produced, which is of such nature as to render traffic control ineffective or unduly difficult at the offset intersection. Jogs of less than 100 feet on such streets, measured along the center line of the intersected street, must be adjusted by curves or diagonals so that the alignment across the street is continuous.
E. Future Extensions of Streets. Where necessary to give access to or permit a satisfactory future division of adjoining land, streets shall be extended to the boundary of the subdivision or partition and the resulting dead-end streets may be approved without a turnaround. Reserve strips and street plugs may be required to preserve the objectives of street extensions.
F. Intersection Angles. Streets shall intersect one another at an angle as near to a 90-degree angle as practical, and no intersections of streets at angles of less than 30 degrees will be approved unless necessitated by topographic conditions. When intersections of other than 90 degrees are unavoidable, the right-of-way lines along the acute angle shall have a minimum corner radius of 12 feet. All right-of-way lines at intersections with arterial streets shall have a corner radius of not less than 12 feet.
G. Existing Streets. Whenever existing streets within a tract are of inadequate width, additional right-of-way shall be provided at the time of the land division.
H. Half-Streets. Half-streets while generally not acceptable may be approved where essential to the reasonable development of the subdivision or major partition, when in conformity with the other requirements of these regulations, and when the council finds it will be practical to require the dedication of the other half when the adjoining property is subdivided or partitioned. Whenever a half-street is adjacent to a tract to be subdivided or partitioned, the other half of the street shall be platted within such tract. Reserve strips and street plugs may be required to preserve the objectives of half-streets.
I. A Cul-de-Sac. A cul-de-sac shall be as short as possible and shall in no event be more than 400 feet long nor serve more than 12 single-family dwellings. All cul-de-sacs shall terminate with a circular turnaround.
J. Street Names. No street name shall be used which will duplicate or be confused with the names of existing streets except for extensions of existing streets. Street names and numbers shall conform to the established pattern in the city and the surrounding area, and shall be subject to the approval of the planning commission.
K. Grades and Curves. Grades shall not exceed six percent on arterials, 10 percent on collector streets or 12 percent on other streets. Center line radii of curves shall not be less than 300 feet on major arterials, 200 feet on secondary arterials or 100 feet on other streets, and shall be to an even 10 feet. Where existing conditions, particularly the topography, make it otherwise impractical to provide buildable sites, the planning commission may accept steeper grades and sharper curves. In flat areas, allowance shall be made for finished street grades having a minimum slope, preferably, of at least 0.5 percent.
L. Streets Adjacent to Railroad Right-of-Way. Wherever the proposed land division contains or is adjacent to a railroad, such distance shall be determined with due consideration at cross streets of the minimum distance required for approach grades to a future grade separation.
M. Marginal Access Streets. Where a land division abuts or contains an existing or proposed arterial street, the planning commission may require marginal access streets, reverse frontage lots with suitable depth, screen planting contained in a nonaccess reservation along the rear or side property line, or other treatment necessary for adequate protection of residential properties and to afford separation of through and local traffic.
N. Alleys.
1. Location. Alleys shall be provided in commercial and industrial districts, unless other permanent provisions for access of off-street parking and loading facilities are made as approved by the council.
2. Intersections. Alley intersections and sharp changes in alignment shall be avoided. The corners of necessary alley intersections shall have a radius of not less than 12 feet.
O. Planning Easements. Where physical conditions require approval of streets less than 50 feet in width, additional easements for planting of street trees or shrubs may be required. [Ord. 9-91 § 1 (Exh. A § 25), 1990; Ord. 9-57 § 1 (Exh. A § 26), 1981].
16.28.030 Blocks.
A. General. The lengths, widths, shapes of blocks shall be designed with due regard to providing adequate building sites suitable to the special needs of the type and use contemplated, needs for convenient access, circulation, control and safety of street traffic, and limitations and opportunities of topography.
B. Sizes. Blocks shall not exceed 1,200 feet in length, except blocks adjacent to arterial streets or unless the previous adjacent outlay or topographical conditions justify a variation. The recommended minimum distance between intersections on arterial streets is 300 feet.
C. Easements.
1. Utility Lines. Easements for electric lines or other public utilities may be required. Easements for utilities shall be a minimum of 10 feet in width and centered on rear or side lot lines. Tie-back easements six feet wide by 20 feet long shall be provided for utility poles along lot lines at change of direction points of easements.
2. Watercourses. Where a subdivision is traversed by a watercourse, drainage way, channel or stream, there shall be provided a storm water easement or drainage right-of-way conforming substantially with the lines of such watercourse, and such further width as will be adequate for the purpose. Street or parkways parallel to major watercourses may be required.
3. Pedestrian and Bicycle Ways. When desirable for public convenience, pedestrian or bicycle way may be required to connect to a cul-de-sac or to pass through an unusually long or oddly shaped block or otherwise provide appropriate circulation. Long blocks parallel to arterial streets may be approved without pedestrian ways if desirable in the interests of traffic safety. [Ord. 9-91 § 1 (Exh. A § 26), 1990; Ord. 9-57 § 1 (Exh. A § 27), 1981].
16.28.040 Lots.
A. Size and Shape. The lot size, width and shape, and orientation shall be appropriate for the location of the land division and for the type of development and use contemplated and shall be consistent with the residential lot size provisions of the zoning ordinance (EPMC Title 17) with the following exceptions:
1. In areas that will not be served by a public sewer, minimum lot and parcel sizes shall permit compliance with the requirements of the Department of Environmental Quality and shall take into consideration problems of sewage disposal, particularly problems of soil structure and water table as related to sewage disposal by septic tank.
2. Where property is zoned and planned for business or industrial use, other widths and areas may be permitted at the discretion of the council. Depth and width of properties reserved or laid out for commercial and industrial purposes shall be adequate to provide for the off-street service and parking facilities required by the type of use and development contemplated.
B. Minimum Lot Sizes. The lot sizes, in addition to conformance with the zoning ordinance (EPMC Title 17), shall be not less than as given in the following table:
|
Type of Lot |
Width |
Minimum Size in Feet Average Depth |
|---|---|---|
|
Corner Lot |
70 feet |
100 feet |
|
Interior Lot |
60 feet |
100 feet |
|
Through Lot with Planting Screen |
60 feet |
120 feet |
In the case of irregular lots, the width shall be measured along the average mean width of the lot. (See Figures in Exhibit “A,” attached to Ordinance No. 9-91 and by reference incorporated and made a part of this title.) In no case shall the average depth be more than two and one-half times the width. Corner lots for residential use shall have extra width to permit appropriate building setback from and orientation to both streets. In the case of cul-de-sacs, the minimum right-of-way width shall be 42 feet.
C. Access. Except as set forth in EPMC 16.20.030, each lot and parcel shall abut upon a street other than an alley for a width of at least 25 feet.
D. Through Lots. Through lots shall be avoided except where essential to provide separation of residential development from major traffic arteries or adjacent nonresidential activities or to overcome specific disadvantages of topography and orientation. A planting screen easement of at least 10 feet and across which there shall be no right of access may be required along the line of lots abutting such a traffic artery or other disadvantageous use.
E. Lot Side Lines. The side lines of lots shall run at right angles to the street upon which the lots face, as far as practicable, or on curved streets they shall be radial to the curve. [Ord. 9-91 § 1 (Exh. A § 27), 1990; Ord. 9-57 § 1 (Exh. A § 28), 1981].
16.28.050 Grading of building sites.
Grading of building sites shall conform to the following standards unless physical conditions demonstrate the propriety of other standards:
A. Cut slopes shall not exceed one and one-half feet horizontally to one foot vertically.
B. Fill slopes shall not exceed two feet horizontally to one foot vertically.
C. The character of soil to fill and the characteristics of lots and parcels made usable to fill shall be suitable for purpose intended. [Ord. 9-91 § 1 (Exh. A § 28), 1990; Ord. 9-57 § 1 (Exh. A § 29), 1981].
16.28.060 Building lines.
If special building setback lines are to be established in a subdivision, they shall be shown on the subdivision plat or, if temporary in nature, they shall be included in the deed restrictions. [Ord. 9-91 § 1 (Exh. A § 29), 1990; Ord. 9-57 § 1 (Exh. A § 30), 1981].
16.28.070 Large lot subdivision.
In dividing tracts into large lots which at some future time are likely to be redivided, the location of lot lines and other details of the layout shall be such that redivision may readily take place without violating the requirements of these regulations and without interfering with the orderly development of streets. Restriction of building locations in relationship to future right-of-way shall be made a matter of record if the council considers it necessary. [Ord. 9-91 § 1 (Exh. A § 30), 1990; Ord. 9-57 § 1 (Exh. A § 31), 1981].
16.28.080 Land for public purposes.
If the city has an interest in acquiring a portion of a proposed subdivision for a public purpose, or if the city has been advised of such interest by a school district or other public agency, and there is reasonable assurance that steps will be taken to acquire the land, then the planning commission may require that those portions of the subdivision be reserved for public acquisition, for a period not to exceed one year, at a cost not to exceed the value of the land prior to subdivision. [Ord. 2000-14 § 2; Ord. 9-91 § 1 (Exh. A § 31), 1990; Ord. 9-57 § 1 (Exh. A § 32), 1981].
16.28.090 Sidewalks.
Sidewalks in each subdivision shall be constructed in accordance with such standards as may be by motion adopted by the city council. Sidewalk construction shall be completed on each individual lot in any subdivision prior to the city building inspector granting a certificate of completion for any construction upon such individual lot. No application for a building permit shall be granted without provision made in the building permit application for construction of sidewalks under the standards of the city as above set out. A notation thereof shall be made upon the subdivision plat giving reasonable notice to any purchaser of a lot in such subdivision of the provisions of this section. [Ord. 9-91 § 1 (Exh. A § 32), 1990; Ord. 9-57 § 1 (Exh. A § 33), 1981].
16.28.100 Improvement requirements.
A. Streets and Pedestrian Ways.
1. All streets and alleys shall be:
a. Cut to the grade and cross-section design approved by the city engineer, having due regard to drainage, the grade of adjoining streets and properties, making allowance for required base and paving material; and
b. Improved by the placing of an adequate rock base of sufficient depth on the portion designed for vehicular traffic.
2. In addition, all streets shall be further improved by the construction, at specified grade, of concrete curbs and gutters so placed and aligned to allow the width for vehicular travel required by the city and, if the street, or any portion of such street, is, or constitutes part of, a primary or secondary arterial street or a business or industrial street, it shall be further improved by asphalt paving to a depth of two inches and the full width between the curbs.
3. Where the council determines that the public interest requires it, the council may require asphalt or concrete surfacing of all or part of any street, alley or pedestrian way, whether or not the same be otherwise required in this chapter.
4. All street improvements shall be constructed to city standards for permanent street and alley construction. Catch basins shall be installed and connected to drainage tile leading to storm sewers or drainage ways as approved by the city engineer. Upon completion of the street improvements, monuments shall be re-established and protected in monument boxes at every street intersection and all points of curvature and points of tangency of street center lines.
B. Surface Drainage and Storm Sewer System.
1. Drainage facilities shall be provided within the land division and to connect the land division drainage to drainage ways or storm sewers outside the land division.
2. Capacity, grade and materials shall be provided by the city engineer’s design. Design of drainage within the land division shall take into account the capacity and grade necessary to maintain unrestricted flow from areas draining through the land division and to allow extension of the system to serve such areas.
C. Sanitary Sewers.
1. Sanitary sewers shall be installed to serve the land division and to connect the land division to existing mains. In the event that it is impractical to connect the land division to the city trunk sewer system, the planning commission may authorize the use of septic tanks if lot areas are adequate considering the physical characteristics of the area.
2. Capacity, grade and materials shall be as follows: trunk or arterial lines shall have a minimum diameter of eight inches with all laterals over 100 feet having a diameter of six inches. Laterals less than 100 feet and serving not more than two houses may be four inches. Sewer lines must be made of concrete or asbestos cement or such other materials as are in the opinion of the planning commission adequate to properly serve the properties that such mains and laterals are designed to serve.
3. If required sewer facilities will, without further sewer construction, directly serve property outside the land division, the following arrangements will be made to equitably distribute the cost:
a. If the area outside the land division to be directly served by the sewer line has reached a state of development to justify sewer installation at the time, the planning commission may recommend to the city council construction as an assessment project, with such arrangements with the land divider as are desirable to assure financing his share of the construction.
b. If the installation is not made as an assessment project, the city will reimburse the land divider an amount estimated to be the proportionate share of the cost for each connection made to the sewer by property owners outside of the land division for a period of 10 years from the time of installation of the sewers. The actual amount shall be as determined by the city council at the time of approval of the plat considering current construction costs.
D. Water System.
1. Water lines and fire hydrants serving the land division and connecting the land division to the city mains shall be installed and the fire hydrants shall be placed at intervals of not more than 800 feet apart measured along dedicated street or 160,000 square feet of subdivision area and not more than 400 feet from structure.
2. Materials, size and location of water mains, valves and hydrants shall be in accordance with the city standards and design. Trunk water lines shall be not less than eight inches in diameter with all laterals not less than four inches in diameter. All water mains and laterals shall be of such other material as are in the opinion of the planning commission adequate to properly serve the properties that such mains and laterals are designed to serve. Two-inch laterals might be extended a maximum of 250 feet, but shall not serve more than two one-family dwellings or the equivalent. Design shall take into account provisions for extension beyond the land division. The city will not except the land divider to pay for the extra cost of oversize mains not necessary to serve the land division.
3. If required water mains will directly serve property outside the land division, the city will reimburse the land divider an amount estimated to be the proportionate share of the cost for each connection made to the water mains by property owners outside the land division for a period of 10 years from the time of installation of the mains. The actual amount shall be as determined by the city council at the time of approval of the plat, considering current construction costs.
E. Street Name Signs. Street name signs shall be installed at all intersections according to city standards.
F. Street Lights. Street lights shall be installed according to city standards. [Ord. 9-91 § 1 (Exh. A § 36), 1990; Ord. 9-57 § 1 (Exh. A § 37), 1981].