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HomeMy WebLinkAbout1.14 Road Waiver Letter RIVER CITY CONSULTANTS, INC.  744 HORIZON COURT SUITE 110  GRAND JUNCTION, COLORADO 81506  970.241.4722 Garfield County Engineer September 7, 2017 Garfield County 195 West 14th Street, Building D, Suite 310 Rifle, CO 81650 970-625-5911 garfield-county.com/engineer/index.aspx RE: LIPA-08-17-8569 Waiver for Road and Demonstration of Compliance (Section 7- 107) for Private Drive and Portion of Grass Mesa Road Greetings, This letter is intended to serve as an application for waiver per Policy 01-14 as discussed in Section 7-107 of the Garfield County Land Use and Development Code. We understand this waiver as being a requirement to show “adequate and safe access” for the thoroughfare in question. The thoroughfare in question is a Portion of Grass Mesa Road and a Private Drive that connects Grass Mesa Road to a proposed tower site at 1885 CR 319 in Rifle, CO (please refer to attached map for location details). On behalf of property owners, we submit this letter for review and request approval for waiver from the Garfield County Engineer. Please direct all correspondence regarding this letter and waiver to Ivan Geer, Principal Engineer with River City Consultants. Thank you, Ivan Geer, P.E. Principal Engineer River City Consultants, Inc. 744 Horizon Court, Suite 110 Grand Junction, CO 81506 Phone: (970) 241-4722 Job Number: 1099-011 RIVER CITY CONSULTANTS, INC.  744 HORIZON COURT SUITE 110  GRAND JUNCTION, COLORADO 81506  970.241.4722 Statement of Adequacy - Grass Mesa Road Portion Grass Mesa Road provides access to private properties located between CR 319 and CR 332 just south of the City of Rifle in Colorado. The portion of Grass Mesa Road (“portion of interest”) discussed in this letter is the very northeast section that connects with CR 319. From the intersection with CR 319, the portion of interest is approximately 0.55 miles in length heading southwest before it reaches the Private Drive entrance also discussed in this letter. Grass Mesa Road is a two-lane dirt road with characteristics that would classify it as “Semi-Primitive” according to Table 7-107 of the Garfield County Land Use and Development Code (LUDC). The road has a typical width of 30’ providing enough room for two 8’ lanes and adequate shoulder space. A drainage ditch runs parallel along the north side of the road and has a typical width of 4’-5’. There are no observable drainage related problems within the portion of interest. All turning radii throughout the portion of interest are larger than 50’ except for an acute turning lane radius on the south side of the entrance to Grass Mesa Road from the intersection with CR 319. At this location, the turning radius appears to be approximately 15’. Although most traffic is expected to turn north onto CR 319 from Grass Mesa Road at this location, an expanded entranceway provides a wide turning radius for any trucks that would turn south. Also, a large parking area near the south side of the entrance provides visibility as well as room for safe stacking. Grades and cross slopes are not defined for the section of interest, but they do appear to be adequate for the designated classification of “Semi-Primitive”. See Site Location and Geometry Map, attached. There are no known traffic studies available for this section of Grass Mesa Road. To determine the appropriate travel demands for the portion of interest we have referenced the Trip Generation Manual (9th Edition, ITE). There are approximately 15-20 private residences and 10 well pads that are accessed from this portion of Grass Mesa Road. The TGM breaks down trip generation values for various land uses. Because there is no “Rural” classification in the Trip Generation Manual (TGM), we have chosen the land use of “Single-Family Detached Housing” (code 210) to calculate the anticipated demand. For this Land Use the TGM provides average vehicle trip ends for dwelling units for weekday peak hour (AM and PM) and weekday peak hour of adjacent street traffic (AM and PM). Please refer to the Trip Generation Table provided on the following page for calculation details. Using the highest rates for the chosen classification in the TGM, we show that PM peak hours on the weekdays are expected to generate the most traffic. The calculated total trips during this peak hour is 20, with 13 entering and 7 exiting. Although the TGM does not provide traffic generation data for well pads, we can provide an estimate that can be used for the purposes of this letter. Due to the rural setting of the area we do not expect much traffic for the well pads. An extremely conservative estimate would be 1-2 trips per day to cover all the established well pads. For 10 well pads this would generate approximately a peak of 6 passenger car equivalent trips per day (1 truck is equivalent to 3 cars), or 3 per hour. Adding this number to the PM peak hour traffic, we estimate the total peak hour traffic for Grass Mesa Road to be 23 trips. This is within the RIVER CITY CONSULTANTS, INC.  744 HORIZON COURT SUITE 110  GRAND JUNCTION, COLORADO 81506  970.241.4722 design capacity range for the “Semi-Primitive” road classification from Table 7-107 of the Garfield County LUDC. Trip Generation Table for Grass Mesa Road Time of Value Average Rate per TGM Calculated By DU (Trips/DU) Distribution Trip Ends Distribution Enter Exit Enter Exit Weekday; peak hour of adjacent street traffic 7-9am 0.75 25% 75% 15.0 (15) 3.8 (4) 0.69 (1) Weekday; peak hour of adjacent street traffic 4-6pm 1.00 63% 37% 20.0 (20) 12.6 (13) 7.4 (7) Saturday; peak hour of generator 0.93 54% 46% 18.6 (3) 10.0 (10) 8.6 (9) Sunday; peak hour of generator 0.86 53% 47% 17.2 (17) 9.1 (9) 8.1 (8) Weekday; AM peak hour of generator 0.77 26% 74% 15.4 (15) 4.0 (4) 11.4 (11) Weekday; PM peak hour of generator 1.02 64% 36% 20.4 (20) 13.1 (13) 7.3 (7) - Table calculations are based on 20 dwelling units (DU) accessing the road. Average Daily Trips, using the Trip Generation Manual for 20 homesis 190 trips per day maximum for the residences. However, single family detached homes are typically associated with subdivisions in municipal settings, not rural residences that are distant from urban centers. In our experience, trip generation for rural residences is less than half of similar urban residences. Well pad traffic is also sporadic and intermittent, and difficult to quantify. Given the remote nature of Grass Mesa Road, and no known complaints or issues, Grass Mesa Road currently is adequate for the average daily trip capacity. There are no know maintenance agreements for Grass Mesa Road and it is currently unknown by the applicant how this road is maintained. The road contains no obvious safety or structural issues observable throughout the portion of interest. RIVER CITY CONSULTANTS, INC.  744 HORIZON COURT SUITE 110  GRAND JUNCTION, COLORADO 81506  970.241.4722 Statement of Adequacy - Private Drive Portion The Private Drive described in this letter is a gated dirt and gravel road with characteristics that would classify it as somewhere between “Semi-Primitive” and “Primitive/Driveway” according to Table 7-107 of the Garfield County LUDC. This portion of road spans approximately ¾ of a mile from Grass Mesa Road through BLM lands before reaching the top of the hill where access to private properties is provided. Refer to the attached Site Map for a visual location of the road portion. The road serves as a main access route for several private properties, including a proposed tower site located at 1885 CR 319. With exception of the Private Drive entrance from Grass Mesa Road, the road is typically 20’-25’ wide with two traffic lanes. This provides enough roadway for two 8’ lanes plus the 2’ shoulder widths, as required for “Semi-Primitive” per Table 7-107 of the Garfield County Land Use and Development Code. A roadside ditch approximately 3’ wide provides drainage from the road as it climbs the hill. This ditch seems to be adequate as no visible signs of erosion to the road or flooding is apparent. On top of the hill, the roadside ditch expands to an approximate 4-5’ width as it heads west paralleling either side of the private access route . Turning radius requirements are met throughout the road portion in question. The smallest turning radius of the road is approximately 50’, which is located at the entrance from Grass Mesa Road. Road grades and shoulder slopes have not been measured for the road, but they do appear to be acceptable per the requirements shown on Table 7-107. See Site Location and Geometry Map, attached. At the entrance location from Grass Mesa Road, the Private Drive has a pinch-point where it is narrowed down to approximately 13’ as it appears to cross over a culvert carrying the ditch on the west side of Grass Mesa Road. Due to the location of this pinch-point, adequate visibility and traffic overflow is provided just west and east of the culvert crossing via expanded road shoulders and the road entrance. There are no known detailed traffic studies performed for this section of road. However, we do have testimony from private land owners to help get an idea of the current and anticipated traffic loads. From this, we know that there are 3 families who currently use the road as the main access to their primary residence. The road is also subject to sporadic traffic from radio tower companies ranging from days to weeks between trips, and with an undetermined peak time of travel. From this, we can deduce that the expected Average Daily Traffic (ADT) for this road is an estimated 20-25 trips per day, and a minimal peak hour traffic of 3 trips per hourThis is within the design capacity range for the “Semi- Primitive” road classification from Table 7-107 of the Garfield County LUDC. The Private Drive is currently maintained by the private property owners. There are no known existing or proposed maintenance agreements for the road section. Other than the identified pinch-point, there are no obvious safety or structural issues associated with the road. 744 Horizon Court, Suite 110 Grand Junction, CO 81506 RIVER CITY C O N S U L T A N T S Phone: 970.241.4722 Fax: 970.241.8841www.rccwest.com Garfield County