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HomeMy WebLinkAboutEng MemoSterling Ridge CC_11-9-21 MemorandumPRIVATE  To: Debbie Root, Senior Planner From: TJ Frans, Project Manager Re: SUB21-000012 & ANN21-000007, Sterling Ridge Subdivision (V2) Date: October 26, 2021 UPDATED Nov 9th, 2021 The Engineering Department provides the following comments on a request for annexation of 54.11 acres with a zone designation of R-2 (Medium Density Residential) and a preliminary plat for Sterling Ridge Subdivision, a 187 lot development, including 173 single-family residential lots and 14 common lots. The subject properties are located south and east of 20710 Ware Road and include parcels R408801000, R3408701200, R340880000, Caldwell, ID. Development Plans Development Plans – Prior to commencing construction, plans must be prepared by the developer’s engineer and approved by the City Engineering Department which shall include the following items: Street section and alignment (including curb and gutter); Sidewalk (sidewalk width based on street classification); Sanitary sewer (per City and DEQ requirements); Potable water (per City and DEQ requirements); Stormwater facilities (per City requirements/storm water manual); Street lighting (per City standards); Street signage (per City and MUTCD requirements); Vertical Datum based on NAVD 88 Datum. General Easements for Public Utilities shall be 10 feet wide minimum along all front lot lines. A minimum10 feet wide easement (or larger if deemed necessary by the City Engineer in order to facilitate future maintenance operations of utilities) may be required along select interior lot lines to facilitate pressure irrigation or other utilities. Appropriate easements for emergency access, transmission lines and/or other utilities shall be clearly indicated, with recorded instrument numbers provided for said easements, on the face of the final plat (visually and in writing). Existing easements shall be shown on all construction drawings. All utilities on and within the boundaries of the subdivision shall be located and/or relocated underground. All street, sewer, water, fire protection, and street light facilities must be dedicated to the City. Some conveyance facilities for stormwater drainage may be eligible for dedication to the City. Construction of facilities to be dedicated and/or within public right-of-way shall be performed by an appropriately licensed public works contractor and shall be inspected by and constructed to City of Caldwell specifications. Prior to commencement of construction in any dedicated right-of-way, or construction of any improvement intended for dedication to the City or connected to a City facility, the City Engineering staff is to be notified. This preferably will take place in a pre-construction conference scheduled by the engineer of record in which all appropriate personnel and utilities are present. Appropriate City personnel are to be notified in advance of all testing (including compaction, pressure and coliform, etc.) and given opportunity to be present during conduct of the testing. The engineer of record or his designated representative is to witness all tests (not covered by City inspectors) and a log of inspection visits and testing results is to be kept by the engineer of record or his representative. The developer is to employ a responsible design professional, preferably the engineer of record, to oversee and inspect construction, to perform and/or observe all requisite testing of completed facilities, and to certify that improvements have been constructed according to approved plans and in compliance with applicable City, State, and Federal standards. The engineer of record shall be held responsible to ensure that subdivision improvements are in substantial compliance with said engineer’s design. Following the construction of the subdivision improvements, the developers engineer shall provide the City of Caldwell Engineering Department with electronic (.dwg) format record drawings spatially referenced to the Idaho State Plane Coordinate System-West Zone, North America Datum (NAD) 83. Vertical control shall be referenced to the North America Datum (NAVD) 88 for future reference and to establish that the engineer of record has caused construction to occur in substantial compliance with the design of said engineer of record. Any note, item or drawing element on the plats, construction drawings, engineering drawings and/or design drawings related to the property inconsistent with City Codes, Policies and/or Ordinances shall not be construed as approved unless specifically addressed and granted by City Council. Rights-of-Way Middleton Road is classified as a Principal Arterial. The applicant shall dedicate as public right-of-way a minimum forty-eight (48) foot half width right-of-way (from centerline) along the entire Middleton Road alignment (per City Standard R-810 A). This section of Middleton Road is maintained by Canyon Highway District 4 (CHD4) and all right-of-way work, plan review, and approvals for access on Middleton Road must be reviewed and approved by CHD4, in addition to the City of Caldwell. All construction of, and access to, Middleton Road shall fully comply with the Middleton Road Corridor Study. Joplin Road is classified as a Collector. The applicant shall dedicate as public right-of-way a minimum thirty-five (35) foot half width right-of-way (from centerline) along the entire alignment (per City Standard R-810 C). All interior local streets classified as residential (including Ware Road) shall be dedicated to the City. The applicant shall dedicate as public right-of-way a minimum fifty-three (53) foot full width right-of-way (per City Standard R-810 E). Ware Road shall include dedication of 26.5’ of right-of-way. Applicant shall dedicate to the City of Caldwell any right-of-way that may be necessary along Middleton and Joplin Roads to facilitate the construction of the roundabout proposed at this intersection. Applicant shall dedicate to the City of Caldwell any required right-of-way along Middleton, Joplin and Ware Roads within 90 days of a written request for right-of-way from the City of Caldwell. Applicant shall dedicate to the City of Caldwell any right-of-way necessary for the proposed roundabout at Middleton/Joplin within 30 days of written request from the City. A note shall be placed on the Final Plat indicating that all rights-of-way are to be dedicated to the public. Street Full frontage half street improvements shall be completed to all classified roads adjacent to the proposed preliminary plat (including Middleton, Joplin and Ware) in accordance with all City of Caldwell standards and specifications. Improvements shall include (but are not limited to) curb, gutter, sidewalk, asphalt, streetlights, joint trench, spare communication conduit along classified roadways, storm drainage facilities, etc. All construction of, and access to, Middleton Road shall fully comply with the Middleton Road Corridor Study (including but not limited to right-of-way widths, road section, intersection locations, turn pockets (aka “loons”) and access controls). Any right-in/right-out access shall have median curbing installed to adequately enforce the right-in/right-out movement at the time said access is constructed. All private driveways shall fully comply with City of Caldwell standards and be approved by the Caldwell Fire Marshall. No lot shall have direct access to/from Middleton, Joplin or Ware roads. Timing for the construction of the roundabout at Middleton Road and Joplin Road is tenuous. If roundabout construction does not begin before Sterling Ridge construction commences, temporary improvements may be required at the direction of the City and/or CHD4 to facilitate north and south bound turn lanes on Middleton Road at Joplin Road. Roundabout frontage improvements on the development corner may also be required in conjunction with adjacent phases of development as directed by the City. Conditions added in the City Council meeting on Nov 1st, 2021: The developer shall work with Mr. Roedel to provide for the right-of-way improvements along Middleton Road and completion of frontage improvements associated with his property, parcel # R34087011 (approximately 560 feet of Middleton Road frontage). The Developer shall continue the frontage improvements at Middleton Road along the entire east property line (R34087011) owned by Mr. Roedel to the intersection of Marble Front Road. The Developer to work with the property owner at the NW corner of Ward Road and Marble Front Road to procure the proper right-of-way and provide those improvements.  Traffic Mitigation The following are the required traffic related mitigation measures for the Sterling Ridge Subdivision resulting from the traffic impact study pursuant to City Code Chapter 10, Article 10. A traffic impact study will be required for this development because of the volume of traffic produced. Provide a cross-access easement allowing use of approaches and cross-access of the site by both onsite and adjacent development. This requirement shall be noted on the final plat. Community Planning Association of Southwest Idaho has computed the average trip length in Canyon County to be 7.3 mi. Traffic impact mitigation should presumably occur at both trip ends so ½ of the trip length should be attributed to each end. It is estimated that trips will encounter a major intersection every half mile along any given path. The capacity of an average fully improved intersection (assumed to be the intersection of a collector and an arterial road) is estimated to be 5,080 vehicles/hour. The estimated traffic resulting from the proposed density in this subdivision based on the the most current Traffic Impact Analysis sets the pm peak hour traffic flow at 187 vehicles for the entire subdivision. Following the City of Caldwell’s mitigation equation ((173 veh/hr*7.3 mile/trip*0.5 trip ends*2inter/mi) / (5080veh/hr)) the total contribution of this development to traffic mitigation shall be 24.9% of a fully improved intersection. This percentage represents the total capacity utilized from each intersection (once fully improved and possibly signalized) encountered by trips generated over the development’s half of the generated trip length. The owner/developer/applicant shall design and construct roughly 24.9% of the signalization improvements needed for an average intersection, as defined, at one or more nearby (within 3.5 miles of the site) deficient locations to be determined by Engineering staff. The Engineering staff shall have reasonable discretion to determine the sites of construction and what design and construction equals roughly 24.9% of the signalization improvements needed for an average intersection. Engineering staff can provide information about applications with whose mitigation efforts the owner/developer/applicant can combine to achieve even units of 100%. The owner/developer/applicant may be allowed, at his option, to contribute monies in lieu of construction to the City of Caldwell Roadway Trust Fund, but the basis for the obligation is for construction. Monetary contributions must be made at a level commensurate with costs to construct the same by the City and as estimated by the City. This alternate provision for payment of money is not a requirement, is for the benefit and convenience of the owner/developer/applicant only and does not constitute an Impact Fee. The average cost of intersection is estimated at $425,000 for procurement of design services, construction, and associated costs by the City, of which 24.9% of that cost is what needs to be covered by this subdivision. The owner/developer/applicant shall keep the City informed of and comply with any additional requirements CHD4 has pertaining to Middleton Road. CHD4 has the final authority to impose Middleton Rd. requirements and said requirements shall be met independent of requirements of the City. CHD4 standards shall be followed for roadway section depth on Middleton Rd. The stricter of City or CHD4 requirements shall be followed for roadway width and traffic mitigation measures on Middleton Rd. Water All on site water mains will need to be looped into existing mains for fire flow and water quality purposes. Internal main sizing and construction plan approval, will be dependent upon the availability of fire flow. Each phase of development shall have a redundant/secondary supply of domestic water. Each buildable lot shall be supplied with potable water. If buildings are constructed to include individual units that could feasibly or will be sold separately, each unit shall be serviced separately The location of water service, including sizing of mains, providing of easements, frontage construction, and offsite construction are to be decided during review of improvement plans. This development will be required to comply with the Water Master Study. Applicant shall construct a 12” water mainline in Middleton Road and Joplin Road along the entire project frontage. Applicant shall stub an 8” water mainline to parcel R3411201000 in the alignment of proposed Caribou Ridge Drive (northernmost access interior roadway connection to Ware Road). If the neighboring development has already constructed their portion of mainline this project shall make a connection to that line. Sanitary Sewer It shall be the responsibility of the applicant’s engineer to verify that connection to existing sewer mainlines will not exceed the functional capacity of said mainlines. Provision for connectivity by future developments shall be met in accordance with current City standards. Sewer service is currently available via a gravity sewer manhole located approximately 75’ west of the intersection of Linden/Ward. A portion of the project site, per the Franklin Sewer Master Plan, is supposed to sewer to the north to the Noble Drain sewer shed and another portion has been master planned to shed south to the aforementioned manhole (the Linden sewer shed). A sewer study was conducted by JUB Engineers to determine if the whole project site could sewer into the Linden Road sewer shed. Upon completion of said study it was determined that all of the subject property could reasonable discharge to the Linden trunk line. The Developer may discharge all or a portion of the proposed project into the Linden sewer shed. See the JUB Engineering, Inc. report title Franklin Sewer Master Plan – Sterling Ridge Revision dated 12/16/2019. The location of sewer service, including sizing of mains, providing of easements, frontage construction, and offsite construction are to be decided during review of improvement plans. This development will be required to installation the trunk lines specified within the most current version of the Franklin Sewer Study that reside within the limits of this preliminary plat. The Developer will be required (where applicable) to extend all sewer and water mainlines to the center of adjacent roadways for connectivity by future developments. Locations of said extensions will be decided during the review of the improvement plans. Each buildable lot shall be provided with individual sewer service. If buildings are constructed to include individual units that could feasibly or will be sold separately, each unit shall be serviced separately. Any easements for sewer lines not in the right-of-way should be at a width sufficient to construct same and not less than 20 feet in width. Easements for adjacent sewer and water lines not in the right-of-way shall be at a width sufficient to construct the same and shall be no less than 30 feet in width. A 20’ wide all-weather surfaces may be required to be constructed over mainlines that fall outside the public right-of-way. All weather surfaces shall be constructed sufficiently to support heavy equipment necessary to construct and maintain sewer under all seasonal weather conditions. Irrigation Existing easements and/or right-of-ways for any irrigation facility shall be determined and clearly indicated on the construction plans and on the final plat (excluding prescriptive easements). Construction across or re-routing of these facilities is subject to approval by the Pioneer Irrigation District and at their discretion, their assigns. The Developer shall maintain any existing upstream drainage rights and downstream irrigation rights across the property. During the design phase of this project, the developer or his engineer is to contact the appropriate irrigation district to help ascertain these rights. Appropriate facilities shall be provided by the developer to convey irrigation and drainage water across the property to take care of these offsite needs. There is to be no discharge of gravity/pressure irrigation return water into the subdivision storm water system. The development is to include a non-potable water pressure irrigation system. The design of this pressure irrigation system is to be reviewed and approved by the Caldwell Municipal Irrigation District prior to construction plan approval. It shall be required that the system will be operated and maintained by the Caldwell Municipal Irrigation District. Applicant shall place the pump station within a platted common lot with a recorded perpetual easement sufficient for convenient access and maintenance of said pump station. The lot shall be owned and maintained by the home owners association. Each lot shall be provided with a pressure irrigation service. All pressure irrigation mainlines shall be located in the public right-of-way, and within a public utility easement of a minimum of 10 feet in width centered over said mainlines as per current City standards. The applicant shall ensure that an adequate continuous irrigation supply flow is available to meet the pressure irrigation system requirements of CMID. Applicant shall pipe the pump station delivery ditch from the source point (head gate) to the pump station. Pump station overflow shall be piped from the pump station to the point of discharge into an irrigation facility/canal/drain/etc. The applicant shall transfer a proportionate share of any existing water right(s), except those held in trust by an irrigation district, to the City of Caldwell for both irrigation and domestic water supply for the subject development. If this should occur, The City shall assist in registering the transfer. All plans and construction drawings submitted to the City of Caldwell for review and approval for any out-of-season irrigation work to be performed within Pioneer Irrigation Facilities shall be submitted to the Caldwell Engineering Department no later than August 15th. Submittal of plans after this date may result in Applicant not receiving plan approval in time to complete out-of-season work. Applicant shall relocate the Weymouth Lateral throughout its alignment along the project boundary. Realignment shall place the lateral in a location that is outside of current or future public right-of-way and in a manner that will prevent the lateral easement from overlapping said right-of-way. Should Applicant elect to relocate the lateral to the south side of Joplin Road it shall be the Applicants responsibility to coordinate with the neighboring property owner to: Determine the appropriate alignment, pipe sizing, pipe type, etc. Obtain & execute an easement from neighboring property owner to Pioneer Irrigation District It shall be Applicants sole responsibility to bear the costs associated with the relocation of the lateral and to cause the physical construction of the lateral in its new location. Storm Drain As noted previously, provision is to be made for the disposal of stormwater drainage in accordance with the City Stormwater Management Manual and any updates adopted subsequent to this application. It is to be noted that retention designs will be denied in most instances. The engineer of record is to provide calculations, which indicate that the assumptions in his stormwater drainage plan comply with the requirements of the stormwater manual. In this case, if a storm water system is existing, the burden of proof is on the developer to verify the capacity is sufficient for the proposed development. The applicant shall identify and retain all historical drainage discharge points from the property for the purpose of draining on-site storm water detention facilities. The final plat drawing should indicate that storm water detention basins are to be placed in common lots in accordance with the referenced Stormwater policy. A note should be placed on the final plat indicating that all areas designated as common areas are to be operated and maintained by the home owners association. There is to be no discharge of storm water overflow into any irrigation water return/discharge facility/ditch/pipe/etc. Plat Prior to approval of the final plat, subdivision facilities must be completed or an appropriate construction security provided. There may be temporary restrictions to the obtaining of building permits, even with acceptable construction security, depending on fire protection, emergency service requirements, and City approval of the sanitary sewer system. A 50% temporary restriction to obtaining of building permits will be enforced until all facility construction has been completed, inspected and certified by the Applicants engineer including all punch list items. A note shall be added to the final stating that no lot shall have direct access to/from Middleton Road, Joplin Road or Ware Road. Upon recordation of the plat, the Engineering Department is to be provided with a PDF copy of the recorded final and 3 full paper set. An electronic (dwg.) copy of the Final Plat suitable for mapping and addressing purposes will be required with Final Plat application submittal.