Chapter 17.40
DESIGN STANDARDS
Sections:
17.40.020 Provisions of the comprehensive plan.
17.40.030 Streets, rights-of-way and accesses.
17.40.110 Parks and recreational areas.
17.40.010 Generally.
Any streets, alleys, easements, blocks, lots or public sites, open spaces, and environmental avoidance/enhancement or mitigation measures within any proposed short or long plat, binding site plan or planned development shall be designed in accordance with Chapter 35.78 RCW et seq. as hereafter amended, and the minimum design standards set forth by the town of Twisp. (Ord. 737 § 2, 2018)
17.40.020 Provisions of the comprehensive plan.
(1) Land which the planning commission has found to be unsuitable for development due to flooding, bad drainage, steep slopes, rock formations, other critical areas as defined by the Growth Management Act and designated by the town, 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 a plat, binding site plan or planned development, shall not be approved, unless adequate methods approved by the town council are planned to overcome these conditions.
(2) Those areas of the town where topographical slopes are 10 percent or more shall be developed 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 developer within 30 days of the request for such information.
(3) The proposed short or long plat, binding site plan or planned development shall provide for such requirements contained in the comprehensive plan.
(4) As further described in TMC 17.40.110, the town shall pursue with the developer all available strategies to reserve for public use lands within an area to be platted, binding site plan or planned development that are identified in the town of Twisp comprehensive plan (as amended) as suitable for educational and recreational purposes. Such strategies may include, but are not limited to, dedication, compensation at full market value, or other mutually agreed upon financial consideration or incentive. (Ord. 737 § 2, 2018)
17.40.030 Streets, rights-of-way and accesses.
The following standards for streets, rights-of-way and accesses apply to all proposed short and long plats, binding site plans or planned developments in the town of Twisp. All streets or accesses with public water, sewer and other town owned and maintained infrastructure shall be dedicated to the public and designed and constructed to the appropriate standard contained herein and the town of Twisp development standards manual.
(1) The arrangement, character, extent, width, grade, and location of all streets shall conform to the town of Twisp comprehensive plan (as amended) 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.
(2) Where such is not shown in the comprehensive plan, the arrangement of streets shall, when applicable, either:
(a) Provide for the continuation or appropriate projection of existing streets in surrounding areas; or
(b) Conform to a plan for the neighborhood approved or adopted by the town council to meet a particular situation where topographical or other conditions make continuance or conformance to existing streets impracticable.
(3) Local access streets shall be so planned as to discourage their use by nonlocal traffic.
(4) Where a development abuts or contains an existing or proposed arterial or collector street, the town council may require reverse frontage with screen planting and a non-access 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.
(5) Nothing less than full-width streets are acceptable except boundary streets on the tract in which the development 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 property.
(6) Where a development is located in an area with a single point of access to a major collector, minor arterial or local major collector, the town 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.
(7) Reserve strips controlling access to streets shall be prohibited except where their control is definitely placed with the town under conditions approved by the town council.
(8) Service drives, where provided in residential areas, shall be a minimum of 20 feet wide in front of residences facing major arterials.
(9) Street jogs with center line offsets of less than 125 feet shall not be allowed.
(10) Easements for private roads, when approved, shall not be less than 30 feet nor more than that required for short or long plats. Easements for access to utilities or service parcels not expected to be in regular use may not be less than 15 feet in width.
(11) Street designs and right-of-way widths for public roads shall be free from any encumbrances and be as shown in the comprehensive plan and where not shown therein shall be not less than as set forth in the town of Twisp development standards manual.
(12) Half streets shall be prohibited except where essential to the reasonable development of the plat, binding site plan or planned development in conformity with the other requirements of this title and where the town council finds it will be practicable to require the dedication of the other half when the adjoining property is developed. Whenever a half street is adjacent to a tract being developed, the other half of the street shall be included as a part of the development.
(13) No street names shall be used which will duplicate or be confused with the names of existing town streets. Street names shall be subject to the approval of the town council.
(14) Street grades shall not exceed the standards set forth in the town of Twisp development standards.
(15) Private access corridors are subject to the approval of the planning commission, public works director and town council and are reviewed on a case-by-case basis.
(16) If private 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 in consultation with the fire chief and planning commission if such greater width is deemed necessary to provide emergency ingress/egress.
(17) If private access by corridor in the same ownership as the lots served is permitted, the area of such corridor shall be included in the lot areas in determining conformance with zoning requirements. Access easement to the town of Twisp will be provided and stated on the face of the plat for access to private and/or town-owned utilities. “Private” shall be labeled on all sewer, water and drainage facilities on the as-built drawings and plat.
(18) Permitted maximum length of a private access corridor shall be 150 feet, except as recommended by the public works director and the planning commission and approved by the town council. All such accesses are subject to compliance with the International Fire Code.
(19) Private access corridors may have official town street designations, provided the private nature shall also be indicated.
(20) Private property may be dedicated to public use as streets by a deed of dedication acceptable to the town or by preparing and recording a plat in accordance with this title.
(21) Street lights shall be provided and installed in conformance with the town of Twisp development standards manual.
(22) 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 short or long plat, binding site plan or planned development connect to or intersect existing roadways, there shall be culvert drains installed in accordance with the town of Twisp development standards manual. (Ord. 737 § 2, 2018)
17.40.040 Utilities.
(1) All underground utilities in all new development shall be installed and maintained in accordance with the town of Twisp development standards All new utilities shall be installed underground except for the following:
(a) Electric, pad-mounted transformers;
(b) Electric transmission systems of a voltage of 15 KV or more;
(c) Service meters at structures;
(d) TV cable amplifiers and distribution taps;
(e) Telephone pedestals and cross-connection terminals;
(f) Temporary services necessary for construction;
(g) Wireless telecommunication devices.
(2) No buildings or structures shall be permitted to be constructed on any town right-of-way, or over any utility facilities. Nonmasonry fences may be allowed to be constructed on or over utility easements if approved by the public works director.
(3) Water. A complete domestic water distribution and fire protection system shall be engineered, installed and inspected at the expense of the developer in conformance with the town of Twisp development standards manual. All water lines and services shall be installed prior to required street improvements. The town of Twisp public works department will supply and install all water connection appurtenances including meters, setters, valves, vaults and cross connection from the water main to the discharge side of the meter. All such work by the town of Twisp public works department and appurtenances shall be charged to the developer in accordance with TMC and the town of Twisp development standards.
The water distribution system shall be designed and constructed in accordance with the town of Twisp development standards manual, town ordinances, and the Washington State Department of Health regulations. Public water mains shall be extended to the far edge of short and long plats, binding site plans and planned developments for future extension by others.
(4) Sanitary Sewer. A sanitary sewer system shall be engineered, installed and inspected at the expense of the developer in conformance with the town of Twisp development standards manual. When a sewer connection is required to an existing sewer mainline, the town of Twisp public works department will supply and install the service connection to the town’s sewer main; provided, that the developer provide a safe excavation access to the sewer main. All such work by the town of Twisp public works department and appurtenances shall be charged to the developer in accordance with TMC and the town of Twisp development standards. When a sewer connection is required to connect to a new or existing sewer manhole, an approved licensed contractor will be employed by the developer to perform all necessary work in conformance with the town of Twisp development standards.
The sanitary sewer system shall be designed and constructed in accordance with the Washington State Department of Ecology regulations and the town of Twisp development standards manual. Public sewer mains shall be extended to the far edge of short and long plats, binding site plans and planned developments for future extensions by others. (Ord. 737 § 2, 2018)
17.40.050 Storm drainage.
All plats, binding site plans and planned developments shall make provisions for on-site collection, retention and disposal of storm and other water runoff in compliance with the Eastern Washington Stormwater Management Manual and town of Twisp development standards manual. The developer must design and install the improvements needed to collect, retain and dispose of runoff on site.
(1) It is the intent of this subsection to adequately provide for suitable drainage provisions in all plats, binding site plans or planned developments. All developments 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.
(2) A drainage plan, where required, shall be prepared by a licensed engineer registered in the state of Washington and submitted to the town 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.
(3) 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 town that the development is located in a drainage problem area, whereby the design storm frequency may be increased accordingly. Drainage plans must identify areas that will accommodate any storm water runoff that is in excess of the designed capacity of the conveyance system. Such runoff must be directed to the location it would have drained to prior to the development. The submitted drainage plan shall incorporate, among other data, a topographical map to clearly define:
(a) The proposed development;
(b) All areas, improved or unimproved, lying upstream and draining to and across the proposed development;
(c) Drainage course, natural or otherwise, to which the proposed development shall drain.
(4) 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. Calculations used for the analysis shall be clearly labeled on the drainage plan set.
(5) 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. 737 § 2, 2018)
17.40.060 Pedestrian ways.
When pedestrian ways are identified in the town of Twisp comprehensive plan and/or trails plan and required by TMC 17.35.150, such improvements are to be provided along all new and existing streets in conformance with the town of Twisp development standards manual. (Ord. 737 § 2, 2018)
17.40.070 Alleys.
(1) Alleys shall be provided in commercial and industrial districts, except that the town 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.
(2) The minimum width of an alley shall be 20 feet.
(3) Alley intersections and sharp changes in alignment shall be avoided to permit safe vehicular movement as determined by the public works director.
(4) Dead-end alleys shall be avoided where possible, but, if unavoidable, shall be provided with adequate turnaround facilities at the dead-end, as determined by the public works director and fire chief. (Ord. 737 § 2, 2018)
17.40.080 Easements.
(1) Utility easements with a minimum width of 20 feet shall be granted to the town of Twisp across lots or centered on rear or side lot lines when applicable and shall remain free of obstacles that would prevent access for maintenance and repair of the utility.
(2) Where a short or long plat, binding site plan or planned development is traversed by a watercourse, drainage, channel or stream, there shall be provided a storm water easement or drainage right-of-way conforming substantially within the ordinary high-water mark 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.
(3) If feasible and appropriate on natural streams, creeks and other bodies of water along or within a proposed short or long plat, binding site plan or planned development, a minimum six-foot pedestrian easement for public use located parallel to and near the ordinary high-water mark is encouraged. (Ord. 737 § 2, 2018)
17.40.090 Blocks.
(1) The lengths, widths and shapes of blocks shall be determined with due regard to:
(a) Provision of adequate building sites suitable to the special needs of the type of use contemplated;
(b) Needs for convenient access, circulation, control and safety of street traffic;
(c) Limitations and opportunities of topography.
(2) Block lengths should not exceed 400 feet.
(3) Pedestrian crosswalks shall be required where deemed essential to provide circulation or safe access to schools, playgrounds, trails, shopping centers, transportation, and other community facilities. (Ord. 737 § 2, 2018)
17.40.100 Lots.
(1) Each lot resulting from the short or long plat, binding site plan or planned development shall conform with zoning regulations. The lot size, width, depth, shape, and orientation shall be in conformance with the applicable town zoning laws, except the lot size in approved planned developments shall be flexible with the total number of lots determined by allowable density, lot coverage and parking requirements.
(2) Each lot shall adjoin a public street unless otherwise 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 requiring access, 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. Any such access shall be compliant with the requirements of the International Fire Code Chapter 5, Appendices C and D and the town of Twisp development standards.
(3) Corner lots for residential use shall have extra width to permit appropriate building setback from and orientation to both streets.
(4) Double frontage and reverse frontage lots should be avoided except where essential to provide separation of residential development from a minor arterial or to overcome specific disadvantages of topography and orientation. No right of access shall be provided along the line of lots abutting such a community arterial or other disadvantageous use.
(5) Applicants that disagree with the decision of the public works director may appeal to the town council, as provided in TMC 17.15.120. (Ord. 737 § 2, 2018)
17.40.110 Parks and recreational areas.
Pursuant to RCW 58.17.110 and related statutes, the town council will require, based on a recommendation from the planning commission, that long plats, binding site plans or planned developments not already served by parks and recreational areas make adequate provisions for these facilities. The need for park and recreation land and/or facilities shall be based on an identified and quantified impact on recreational resources, as described in the parks and recreation element of the town of Twisp comprehensive plan, and such facilities are reasonably necessary as a direct result of the proposed development or required to mitigate the direct impact of the development. The provisions shall be made by either designating a portion of the land as either private or public parks and recreational areas or, in the alternative, entering into a voluntary agreement to contribute funds to the town for park purposes. Lands designated for park and recreational purposes are subject to the following:
(1) The nature of the park or recreation area shall be clearly indicated on the plat.
(2) Lands dedicated to the town for public parks or recreational areas, other than streets and alleys, shall be conveyed by deed from the developer in conjunction with final approval of the plat.
(3) Parks and recreational areas proposed to remain in private ownership shall be developed as needed to accommodate the development in which the park and recreation area is located.
(4) As an alternative to dedication of public parks and recreational areas, the developer may voluntarily choose to contribute to the town, for park purposes, a payment approximately equal to the value of the land which the town would otherwise have required to be designated for parks and recreational areas. Payment of cash in lieu of land for park purposes shall be made by the developer to the town before final long plat approval is given. The payment shall be deposited into a reserve account from which funds may be expended for parks and recreational uses agreed upon by the town council and the developer to mitigate the identified direct impact.
(5) Proposed park and recreational areas shall be developed, depending on intended use, according to the development standards defined in the parks and recreation element of the town of Twisp comprehensive plan. (Ord. 737 § 2, 2018)