Chapter 16.32
DESIGN STANDARDS
Sections:
16.32.020 Provisions of the comprehensive plan.
16.32.030 Streets, rights-of-way and accesses.
16.32.110 Parks and recreational areas.
16.32.010 Generally.
A. Any streets, alleys, easements, blocks, lots or public sites, open spaces and environmental avoidance/enhancement or mitigation measures within any proposed plat shall be designed in accordance with the minimum design standards set forth by the city of Tonasket.
B. Any proposed deviation from the following standards shall be requested and reviewed concurrently with the short subdivision or subdivision application in accordance with Chapter 16.36 TMC. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.020 Provisions of the comprehensive plan.
A. Land which the planning commission has found to be unsuitable for subdivision due to flooding, bad drainage, steep slopes, rock formations, other critical areas, as defined herein, or other features likely to be harmful to the safety and general health of the future residents, and which the planning commission considers inappropriate for subdivision, shall not be subdivided, unless adequate methods approved by the city are planned to overcome these conditions. The administrator may require engineering report(s) or other additional information including the best available science to ensure such areas are appropriate for subdivision, or appropriate mitigation is provided.
B. Those areas of the city where topographical slopes are 10 percent or more shall be subdivided in conformance with such additional requirements as deemed appropriate. Such additional requirements shall be obtained from the appropriate department heads by the planning commission or administrator and presented to the subdivider within 30 days of the request for such information.
C. The proposed subdivision shall provide for such requirements contained in the comprehensive plan.
D. The subdivider shall make available for public acquisition by dedication or at a reasonable price such land in the area to be subdivided as designated by the comprehensive plan for educational and recreational purposes. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.030 Streets, rights-of-way and accesses.
The following standards for streets, rights-of-way and accesses apply to all proposed subdivisions in the city of Tonasket:
A. The arrangement, character, extent, width, grade and location of all streets shall conform to the general comprehensive plan and shall be considered in their relation to existing and planned streets, to topographical conditions, to public convenience and safety, and in their appropriate relation to the proposed uses of the land to be served by such streets;
B. Where such is not shown in the comprehensive plan, the arrangement of streets in a subdivision shall, when applicable, 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 city council to meet a particular situation where topographical or other conditions make continuance or conformance to existing streets impractical;
C. Minor streets shall be so planned as to discourage their use by nonlocal traffic;
D. Where a subdivision abuts or contains an existing or proposed arterial street (U.S. 97, S.R. 20 and local arterials as designated in the transportation element of the city of Tonasket comprehensive plan), the city council may require reverse frontage (with screen planting) and a nonaccess reservation along designated property lines, or such other treatment as may be necessary for adequate protection of residential properties and to afford separation of through and local traffic;
E. Nothing less than full-width streets except boundary streets shall be on the tract in which the plat is located. In the case of boundary streets with less than full-width, there shall be included a conditional dedication clause on the face of the plat which will reserve the outer one foot of the boundary street from public usage until such time as the remainder of the right-of-way necessary to assure a full-width street is dedicated from the adjoining parcels;
F. Where a subdivision borders on or contains a railroad right-of-way or limited access highway right-of-way, and there exists a reasonable possibility of a future overpass or intersection, the city council may require a “reservation for potential future right-of-way.” Such reservations for potential future right-of-way shall be laid out with due regard for the requirements of approach grades and future grade separations;
G. Reserve strips controlling access to streets shall be prohibited except where their control is definitely placed with the city under conditions approved by the city council;
H. Service drives, where provided in residential areas, shall be a minimum of 20 feet wide in front of residences facing major arterials;
I. Street jogs with centerline offsets of less than 125 feet shall not be allowed;
J. Rights-of-way for private roads shall not be less than 30 feet nor more than that required for regular plats. Rights-of-way for access to utilities or service parcels not expected to be in regular use may not be less than 15 feet in width;
K. A tangent at least 50 feet long shall be introduced between reverse curves on arterials and collector streets;
L. When connecting street lines deflect from each other at any one point by more than 10 degrees, they shall be connected by a curve for arterial and collector streets, for which the degree of curvature shall be determined by the public works director;
M. Streets and/or road intersections shall be laid out so as to intersect as nearly as possible at right angles and no street shall intersect any other street at less than 80 degrees and at street intersections; property line corners shall be rounded by an arc, the minimum radius of which shall be 20 feet;
N. Street designs and right-of-way widths free from any encumbrances shall be consistent with those standards outlined in “City and County Design Standards for Construction of Urban and Rural Arterial and Collector Roads” as summarized in the comprehensive plan and where not shown therein, shall be not less than as follows:
|
Street Type |
Minimum Right-of-Way Width* |
Minimum Curb-to-Curb Pavement Width |
Maximum |
|---|---|---|---|
|
Primary arterial |
80 feet |
54 feet |
6 percent |
|
Collector street |
60 feet |
40 feet |
6 percent |
|
Minor residential street over 500 feet in length |
60 feet |
40 feet |
8 percent |
|
Minor residential street less than 500 feet in length which cannot be extended |
50 feet |
32 feet |
8 percent |
|
Circular-end cul-de-sac |
50 feet (radius) |
50 feet (radius) |
|
|
Hammerhead-end cul-de-sac* |
width of |
width of |
grade of |
*Total length of short street making up hammerhead end shall be a minimum of 100 feet in length.
A reduction of the right-of-way width may be permitted where topography is a problem or when the proposed street connects to or is the extension of any existing platted street having a right-of-way width less than the required minimum, when approved in accordance with Chapters 16.36 and 16.40 TMC;
O. The street area between the curbs shall be constructed with the following minimum compacted ballast and surfacing materials:
|
Residential Minor Streets |
|---|
|
2" Asphalt concrete pavement |
|
2" Crushed surfacing-top course (5/8"-0) |
|
4" Ballast (2-1/2"-0) |
|
Primary Arterial, Collector Streets, Commercial, and Industrial Areas |
|---|
|
3" Asphalt concrete pavement |
|
3" Crushed surfacing – top course (5/8"-0) |
|
6" Ballast (2-1/2"-0) |
P. Half streets shall be prohibited except where essential to the reasonable development of the subdivision in conformity with the other requirements of this title and where the city council finds it will be practicable to require the dedication of the other half when the adjoining property is subdivided. Whenever a half street is adjacent to a tract being subdivided, the other half of the street shall be included as a part of the subdivision;
Q. Dead-end streets, also referred to as cul-de-sacs, designed to be so permanently, may serve a maximum potential of 200 vehicles per day and should otherwise be limited to a length of 600 feet. Cul-de-sacs shall be provided at the closed end with a turnaround having an outside right-of-way diameter of at least 100 feet, or a hammerhead turnaround of 100 feet in total length including the width of the street to which it is perpendicular;
R. No street names shall be used which will duplicate or be confused with the names of existing city streets. Street names shall be subject to the approval of the city council;
S. Street grades shall not exceed the standards set forth in subsection (N) of this section, depending upon topographic conditions and whether the street is designated as a community arterial, collector city street, or access city street;
T. If access corridors are permitted, the minimum corridor width to serve one or two lots shall be 20 feet, and to serve three or four lots, shall be 30 feet. Greater width may be required at the discretion of the public works director and the planning commission, if such greater width is deemed necessary to provide emergency ingress/egress;
U. If access by corridor in the same ownership as the lots served is permitted, the area of such corridor shall not be included in the lot areas in determining conformance with zoning requirements;
V. Permitted maximum length of an access corridor shall be 300 feet, except as recommended by the planning commission and approved by the city council, it may be longer; provided, that if a lesser length serves the lots in the subdivision, such shorter length shall be the maximum permitted;
W. Access corridors may have official city street designations, provided the private nature shall also be indicated;
X. Access corridors shall not be used to serve more than four lots;
Y. Private property may be dedicated to public use as streets by a deed of dedication acceptable to the city or by preparing and recording a plat in accordance with this title;
Z. Curb, gutter, pavement and storm drainage facilities shall be installed on all existing or proposed streets to prevent storm water erosion and damage, unless such requirement is waived by the city council. The curbs are to be combination curb and gutter of concrete and shall be poured as a single unit according to plans and specifications supplied by the public works director;
AA. Street lights shall be provided and installed in conformance with the following standards:
1. One street light at each street intersection;
2. At least one street light per 300 feet;
3. All street lights shall be LEDs.
BB. Guard rails shall be provided on trestles or bridges and guard fences shall be provided on fills or culverts over four feet in height. Where streets or roads of the subdivision connect to or intersect existing roadways, there shall be installed culvert drains of metal or concrete pipe of not less than 12 inches diameter;
CC. Where there may be existing streets that are inadequate in size to serve the needs of the subdivision, or if such existing streets need improvements to adequately serve the subdivision, the subdivider may provide right-of-way and/or improvements to remedy such inadequacies that may otherwise cause the subdivision to be denied. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.040 Utilities.
A. All underground utilities in all new residential areas shall be installed and maintained at a depth of not less than three feet below the graded surface of said street, provided existing installations may be maintained at the present level until replaced.
B. All new utilities shall be installed underground except for the following:
1. Electric, pad-mounted transformers;
2. Electric transmission systems of a voltage of 15 KV or more;
3. Service meters at structures;
4. TV cable amplifiers and distribution taps;
5. Telephone pedestals and cross-connection terminals;
6. Temporary services necessary for construction; and
7. The subdivider demonstrates to the city council that it is infeasible.
C. No buildings or structures, except fences, shall be permitted to be constructed on utility easements, or over any utility facilities. Masonry fences will be considered as structures, rather than fences.
D. Water. A complete domestic water distribution and fire protection system shall be installed at the expense of the developer in conformance with the comprehensive water plan and standard practices of the city. All water lines and services shall be installed prior to street improvements and structural development.
The water distribution system shall be designed and constructed in accordance with the State Department of Health regulations and with the standard practices of the city. Fire hydrants shall be installed, at the expense of the developer, at locations determined necessary by the fire chief.
The city, at its discretion, may direct that water main diameters in excess of that needed by service and fire protection for the subdivision be installed. If the city directs such oversizing, the city will pay the difference in pipe material cost between the pipe diameter required for the subdivision and the city-directed oversize diameter pipe.
E. Sanitary Sewer. A sanitary sewer system shall be installed at the expense of the developer with a separate connection to the city sewer system for each lot and shall be constructed in conformance with the comprehensive sewer plan and standard practices of the city.
The sanitary sewer system shall be designed and constructed in strict accordance with the State Department of Ecology “Criteria for Sewage Works Design” (current edition).
The city, at its discretion, may direct that sewer main diameters in excess of that needed for service for the subdivision be installed. If the city directs such oversizing, the city will pay the difference in pipe material cost between the pipe diameter required for the subdivision and the city-directed oversize diameter pipe. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.050 Storm drainage.
A. All developments shall make provisions for collection, retention and disposal of storm and other water runoff. The method of storm drainage handling will be dependent on the location of the development. Where access to the city’s storm drainage utility is feasible, the developer shall design and install a collection system and with a connection to the city’s utility according to specifications provided by the city. Where access to the system is not available, the developer must design and install the improvements needed to collect, retain and dispose of runoff on site. Such method of disposal must meet current local, state and federal standards for runoff collection, retention and disposal.
B. It is the intent of this section to adequately provide for suitable drainage provision in all short plats or regular subdivisions. All subdivisions shall provide for drainage such that their development does not conflict with present drainage patterns, or create a drainage problem within itself or for its neighbors. Most common short subdivisions are not anticipated to cause such conflicts; therefore, they will be subject to the requirements of this section only when review of the short subdivision by the city reveals, in its opinion, that such conflicts exist or potentially exist. When the city makes such determination, the subdivider shall conform to this section. Regular subdivisions shall comply with this section in all cases.
C. A drainage plan, where required, shall be prepared by a licensed engineer registered in the state of Washington and submitted to the city for review and approval for any proposed land development that will increase the quantity of or in any way alter the drainage runoff occurring prior to development.
D. Design calculations for peak flow and peak volume storage requirements shall be based on a design storm frequency of 10 years unless it is determined by the city that the development is located in a drainage problem area, whereby the design storm frequency may be increased accordingly.
E. The plan shall provide for the on-site detention and/or retention of the total water intercepted and collected by the development and the areas (improved or unimproved) lying and draining presently to and through the proposed development, for the design storm, unless other natural or manmade systems are available for use.
F. Detention and/or retention of storm water runoff from any proposed land development shall be accomplished by storm water holding facilities either open or closed or by introduction, on site, of storm water into permeable soils via an infiltration system.
G. The drainage plan shall incorporate all calculations for the determination of the required size of the system. Said calculations shall be based on required criteria herein stated and upon an analysis of estimated runoff from areas contributing runoff to those facilities. Peak flow analyses shall be done using the Rational Method. Storage volume quantities shall be computed by the Rational-Stored Rate Method. The assumption for the outflow rate used in the Stored Rate Method will need to be verified by the developer by actual field testing in the case of filtration systems. Collection systems shall be either gravity pipe systems, open channels, or a combination of the two.
H. The overflow of runoff in excess of the design storm quantities must be situated or directed to where it would have overflowed under the conditions existing prior to proposed development. The capacity of the drainage course downstream of the development may be required to be evaluated. The submitted drainage plan shall incorporate, among other data, a topographical map to clearly define:
1. The proposed development;
2. All areas, improved or unimproved, lying upstream and draining to and across the proposed development; and
3. Drainage course, natural or otherwise, to which the proposed development shall drain.
Said plans shall include a plan-profile of the systems including cross-sections of all open ditches and channels. Hydraulic and physical data such as grades, bottom elevations of ditches and channels, inverts of pipes at all structures such as manholes and catch basins, sizes and lengths of all pipes, length of ditches and channels, and top elevations of all catch basin covers shall be called out. This includes the invert elevations of the existing or other proposed storm drainage systems that the subject drainage plan proposes to tie into. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.060 Sidewalks.
Sidewalks shall be provided along all new and existing streets consistent with the comprehensive plan and in conformance with the following minimum standards:
A. Sidewalks shall be located in the right-of-way in accordance with the direction of the public works director;
B. Sidewalks shall be placed along at least one side of all minor streets and shall have a minimum width of four feet;
C. Sidewalks shall be placed along both sides of all arterial streets and shall have a minimum width of seven feet;
D. Sidewalks in commercial areas shall be 10 feet wide unless the city council determines that a lesser width is sufficient;
E. Where a proposed subdivision is located adjacent to an existing street, the subdivider is not required to provide a sidewalk on the opposite side of the street; and
F. Curb ramps for the physically handicapped shall be constructed pursuant to RCW 35.68.075 and 35.68.076 at all intersections and other appropriate locations. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.070 Alleys.
A. Alleys shall be provided in commercial and industrial districts, except that the city council may waive this requirement where other definite and assured provision is made for service access, such as off-street loading, unloading and parking consistent with and adequate for the uses proposed.
B. The minimum width of an alley shall be 20 feet.
C. Alley intersections and sharp changes in alignment shall be avoided but, where necessary, corners shall be cut off sufficiently to permit safe vehicular movement as determined by the public works director.
D. Alley intersections shall be laid out so as to intersect as nearly as possible at right angles and no alley shall intersect any other street at less than 80 degrees.
E. Dead-end alleys shall be avoided where possible but, if unavoidable, they shall be provided with adequate turnaround facilities at the dead-end, as determined by the public works director. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.080 Easements.
A. Easements across lots or centered on rear or side lot lines shall be provided for utilities. Utility easements shall have a minimum width of 15 feet. Damage to properties within the easement area are at the owner’s risk and are not subject to reimbursement by the city.
B. Where a subdivision is traversed by a watercourse, drainage 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 for construction, or maintenance, or both, as will be adequate for the purpose. Parallel streets or parkways may be required in connection therewith.
C. A six- to eight-foot pedestrian walking easement, parallel and near the water’s edge at any given time, is encouraged if feasible and appropriate on natural streams and creeks and other bodies of water along or within a proposed subdivision. In the construction of such a trail, a tread of three to four feet in width is to be used and only such vegetation as necessary to establish such tread may be removed. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.090 Blocks.
A. The lengths, widths and shapes of blocks shall be determined with due regard to:
1. Provision of adequate building sites suitable to the special needs of the type of use contemplated;
2. Needs for convenient access, circulation, control and safety of street traffic; and
3. Limitations and opportunities of topography.
B. Block lengths should not exceed 1,000 feet.
C. Pedestrian crosswalks may be required where deemed essential to provide circulation or access to schools, playgrounds, shopping centers, transportation and other community facilities. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.100 Lots.
A. Each lot resulting from the subdivision of an area shall conform with zoning regulations.
B. Each lot shall adjoin a public street unless one of the following alternatives is approved by the public works director and recommended for approval by the planning commission. Lots may have access to a public street by an access corridor in the same ownership as the lots served, or by recorded easement over an access corridor in other ownership, whichever in the discretion of the approving officials is the best method of access based on existing adjacent development and potential development in as yet undeveloped adjacent properties, and on existing streets and potential future streets; further provided, that in the event the subdivider disagrees with the decision of the officials, he may take the matter to the city council for final decision.
C. The lot size, width, depth, shape and orientation shall be in accordance with the applicable city zoning laws.
D. Corner lots for residential use shall have extra width to permit appropriate building setback from and orientation to both streets.
E. The subdividing of the land shall be such as to provide, by means of a public street, each lot with satisfactory access to an existing public street.
F. Double frontage and reverse frontage lots should be avoided except where essential to provide separation of residential development from traffic arteries or to overcome specific disadvantages of topography and orientation. An easement of at least eight feet, and across which there shall be no right of access, shall be provided along the line of lots abutting such a traffic artery or other disadvantageous use. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).
16.32.110 Parks and recreational areas.
Pursuant to RCW 58.17.110 and related statutes, the planning commission may recommend and the city council require that plats with less than two-acre lot sizes in urban areas not already served by parks and recreational areas to designate up to five percent of their land exclusive of streets, as either private or public parks and recreational areas subject to the following:
A. The nature of the park or recreational area shall be clearly indicated on the plat;
B. The acquisition of the land required by the city for public parks or recreational areas, other than streets and alleys, shall be obtained by deed from the developer in conjunction with final approval of the plat;
C. Such mitigation of park and recreational land and/or facilities shall be based on an identified and quantified impact on recreational resources;
D. Repealed by Ord. 786.
E. Parks and recreational areas proposed for dedication shall at a minimum have an efficient irrigation system and suitable landscaping installed;
F. Parks and recreational areas proposed for dedication shall require low maintenance and a minimum of irrigation and landscaping; and
G. Parks and recreational areas proposed to remain in private ownership shall be developed as needed to accommodate the development in which the park and recreational area is located. (Ord. 786 § 1 (Exh. A), 2017; Ord. 587 § 1, 2001).