Loading...
HomeMy WebLinkAbout2020.07.22_Engineering Comments Gorsuch Haus Detailed ReviewGorsuch Haus Detailed Review Engineering Comments July 23, 2020 PD Development Agreement: 1. Article IV. Public Improvements – All Exhibits referenced in this section need to be submitted to the Engineering Department for review. This section of the PD shall include all public improvements including those that overlap with the Lift One Lodge. Given the overlapping complexities of the LOL and Gorsuch projects the PD Development Agreement needs to speak to the expectations of installation timing for all public infrastructure including but not limited to (1) the 16" waterline connection from S Aspen St to Monarch St (2) the electric primary from S Aspen St to Monarch (3) any necessary interim drainage and mudflow infrastructure should one project proceed ahead of the other (4) the condition of the termination of S aspen St for both vehicles and pedestrians should LOL proceed ahead of Gorsuch and (5) the completion of all Dean St improvements in regards to Gorsuch or if those improvements are solely tied to Lift One Lodge. 2. Section 3.5 c states “Soil stabilization shall be located within the property boundaries or follow Section 21.12.140 of the Municipal Code.” This is acceptable. Section 3.21 B of the Draft PD Development Agreement proposes a fee-free easement. This is not acceptable to the COA Engineering Dept. 3. If just the cul-de-sac and not the whole street is snowmelted, snow plows will use the cul-de-sac to turn around. The plows have chains on the tires that will damage a concrete cul-de-sac. Damage to snowmelted concrete will have additional costs to maintain. The maintenance and replacement will be the responsibility of the Gorsuch Haus. The City will not be responsible for damage incurred by Street maintenance. This language shall be added in the PD Agreement. 4. Section 30 of Ordinance 39 specifies the process for determining snowmelt along all of South Aspen St. This process needs to be acknowledged and included in the PD Agreement. The development agreement shall have the same winter maintenance process agreement for South Aspen St that was laid out in Ordinance 39. Use of the Public ROW: 5. The COA Engineering Department does not approve of waiving all fees for the use of the ROW during construction. It is not appropriate to waive the ROW fees for the construction of this project. Ordinance 39 clearly states the projects stabilization shall be located within the property boundaries or follow section 21.12.140 of the Municipal Code. Section 21.12.140 requires fees be paid for use of the ROW for stabilization. The ordinance permits the use of the ROW for stabilization but does not waive fees. In addition to stabilization in the ROW fees, the fees for rental of the ROW for staging storage and laydown shall not be waived. Easements: 6. Gorsuch Haus will need permission from Mountain Queen to change their drainage and access easement. Maintenance of an open channel is very different than maintenance of a road with pipe. Provide documentation of this approval. 7. The subdivision Plat needs to show easements for channel flow, not just infrastructure. 8. The access easement is written to provide pedestrian and bicycle access from Hill St to Monarch but not up the ajax mountain access road. Pedestrian and Bicycle access should be provided up the mountain road. The DRC response document states a public access is agreed and documented but it is not shown in an easement on the plat. Section 3.7 c of the Development agreement only addresses pedestrian and bicycle access from Hill St ROW to Monarch St ROW. 9. While the Shadow Mountain transformer has been relocated to the transformer by South Aspen Townhomes, there are still utility meters for Shadow Mountain at the south side of their property. How will these be accessed? Provide adequate easements and accessibility. Slope Stability: 10. Page 1 of the slope stability report does not support the oversteepening of the hillside and recommends structural walls on either the building or hillside. This needs to be addressed where the civil plans propose 1:1 slopes. The 1:1 slopes are not approved. Revocable Encroachment License Hill Street ROW: 11. In addition to the Hill St encroachment agreement, a standard encroachment license will be required at the conclusion of the project prior to CO. 12. Engineering needs to review Exhibit A and B reference in the Encroachment license. 13. Language needs to be added to the permanent encroachment license agreement that should the City need to perform work on the 16" waterline or electric primary within the Hill St ROW the replacement of the "landscape improvements" removed for excavation of the utilities will be at the sole cost of the Gorsuch property to replace. 14. In Section 1. Encroachment Permission delete "building improvements". There shall be no building improvements in the Hill St ROW 15. Finalize the call out for the encroachment distance. I think it is 110 ft of the westernmost portion of the Hill St ROW. Mudflow: 16. Per the Tetra Tech mudflow report 3' of freeboard is needed along the south side of Gorsuch Haus. It does not appear this is met given the FFE and door openings shown on sheet C.2.03. Please address. Also reference window plan to show all windows have 3' freeboard. Transportation Impact Analysis: 17. The TIA as submitted is accepted. The necessary number of trips is mitigated. Civil Plans: 18. The headwall and catch basin will be the maintenance responsibility of Gorsuch, as the City does not have the equipment to maintain the catch basin over the retaining wall. The responsibility of the catch basin to Gorsuch will be memorialized in a permanent encroachment license. 19. The LOL and SATH PUDs required public parking spaces be provided at the top of South Aspen St. The response to project review DRC comments stated that the parking spots are moved in to the parking garage. The cul-de-sac design is great and should not be altered to add parking spots but the project needs to ensure the requirements from the previous approvals for SATH and LOL are properly acknowledged. 20. Given the proposed improvements, it is not clear that the trees along the property line of the Mountain Queen and Caribou condos can be retained. This needs to be worked out with Parks. Call out the cut depth and location in reference to the drip lines. 21. The stormwater vault placed partially in the ROW will be accepted as a permanent encroachment. The vault treats approximately 1,000 sf of the ROW thus it is permitted. 22. The plat revokes the permanent encroachment license of Shadow Mountain Townhomes with a plat note. A proper process is needed to revoke the existing encroachment license and issue a new encroachment license for Shadow Mountain. The new license will require a new survey exhibit and coordination with Shadow Mountain. 23. Sheet C2.00 Cul-De-Sac Plan Profile and Grading a. Snowmelt in the cul de sac is not approved until a design solution is agreed upon by the applicant and City of Aspen that will eliminate any possibility of ice damning at the interface between the snowmelt and non snowmelt areas on South Aspen St. While some alternatives have been discussed with Sopris and COA Engineering, we do not feel confident that these plans guarantee a design solution. Possible solutions that should be fully vetted are (1) trench drain (2) valleypan (3) grooved pavement (4) ending snowmelt at a less steep location (5) altering grading. b. It appears the west side of the retaining wall extends onto Shadow Mountain Town homes property. Is this the existing Shadow Mountain stairway wall or a new improvement? Improvements cannot extend onto neighboring properties without written approval. Show the Shadow Mountain Town home Improvements on the survey and planset to demonstrate the proposed Gorsuch plans tie in to the Shadow Mountain Improvements without any issues. c. Provide vehicle protection and a pedestrian deterrent along the north side of the cul-de- sac so people do not walk across the cul de sac and jump down to the sidewalk and so that vehicles do not cross the landscape buffer to the sidewalk 4 ft lower. d. The trees next to Shadow Mountain Townhomes will not survive the installation of the retaining wall and inlet and associated grading. It is the City Foresters discretion if the tree removal will be permitted. The plans should show removal. e. Call out the highpoint at the garage entrance. Drainage exterior to the garage must drain to the storm system, drainage interior to the garage must drain to interior drains that are routed to the sanitary sewer. Demonstrate this is the case. 24. Sheet C.2.03 Conceptual Perimeter Grading Plan a. The design proposes a cut in excess of 10' for the drainage swale in the South Aspen St ROW. At Project Review the Engineering Department commented that a swale was an appropriate use of the ROW in this area. However, it appears the 1:1 slopes, 2:1 slopes, and excessive cut is proposed to benefit the Gorsuch building, not because it is necessary for drainage or mudflow purposes. Looking at the cross sections the east side of the swale is much lower than the west to accommodate the building not the drainage. The use of the ROW in this manner is not fair to the Shadow Mountain Townhomes and further limits available access for any maintenance needs. The Engineering Department does not approve nor support such a drastic cut. An alternative design needs to be proposed that limits the cut depth, and the steepness of the side slopes. Extending the storm system and catch basin up the mountain might be a more acceptable alternative. b. Due to the unusual difficulty to access the catch basin, the inlet will require a revocable encroachment license and will be the responsibility of the Gorsuch Haus to maintain. Additionally, an easement shall be provided up the summer road and around the building in the event the city needs access the west swale and inlet. c. Provide a detail of the riprap for the west swale. The swale should be armored below with grass on top. The SATH project had a hard time getting vegetation stabilized over the rip rap on the existing inlet. How will Gorsuch accomplish stability and aesthetics? 25. Sheet C.2.05 Mountain Road Sections a. The plan proposes 2:1 slope which is in excess of the COA standard of 3:1. Per the stability report the 2:1 slope is acceptable with appropriate vegetative stabilization. Include a note on the stabilization plan. 26. Sheet C.2.06 West Swale Plan, Profile and Sections a. The West Side Swale Profile has a note that calls out 3:1 (Max) Side Slopes. The side slopes on the cross sections exceed 3:1. Section 2-2 has 2:1 slopes. The max slope should be limited to 3:1 as the note suggests. Please address. 27. Sheet C.3.00 Master Conceptual Utility Plan a. Does shadow mountain have the access they need for the meters and utilities left in the south east corner of their property? Provide an easement around Gorsuch so Shadow Mountain Townhomes can access their utilities. b. Has Holy Cross reviewed the proposed easement to the transformers and agreed there is adequate easement width for accessibility? 28. Sheet C.3.03-C3.04 16” Water Main Plan and Profile a. The Second Amendment to Development Agreement for Lift One Lodge Subdivision/PUD deferred the installation of the 16" waterline from S Aspen St to Monarch St. Originally it was to be constructed with South Aspen Townhomes but the amendment allowed the installation to take place when LOL is developed. A timeline was set for five years from 2017 with the ability to extend via written decision by the City Engineer. The 16" waterline must be constructed prior to CO of either the LOL or Gorsuch property. This shall be addressed in the Gorsuch Development Agreement. Lift One Lodge will need to make a formal request to extend the completion date beyond 2022. b. Call out 10' separation between outside diameter of the waterline and outside diameter of the relocated sanitary service line. c. The waterline replacement on Monarch St needs to match what was approved in the original LOL/SATH approvals which is shown in the diagram below. All pipe needs to be replaced to the gate valves north of the east-west 8" CIP. The 16" line needs to be replaced to the gate valve beyond the service line to the east i. d. Can the waterline be constructed without impacting the trees on the Caribou property? The applicant needs to show the exact location and excavation depth to Parks Dept for their approval. e. Fire flow calculations for a 6" service line will be required at building permit. Full fire flow calcs for a 4" line demonstrating the 4" line fails also will be required at building permit. f. Include a note that the two dry line hydrants will be a different model than the standard water distribution hydrant so there is no confusion in the future or mix up thinking the hydrants have a permanent water source. g. The portion of the waterline in the Hill St ROW was deferred for construction from the South Aspen Town homes project because there was concern about the installation of the waterline prior to excavation of LOL. How has this been resolved? The waterline must be constructed under whichever project is constructed first. Does this work with the proposed excavation and project sequencing? 29. Sheet C.4.04 West Storm Pipe Profile a. The Existing Inlet OS5 in the planter box next to Shadow Mountains drive entrance does not collect runoff from any area. It may make more sense and look a lot better to convert it to a manhole or remove it. This can be more closely looked at and refined at building permit and is not necessary for landuse approvals. 30. Sheet C.4.06 East Storm Pipe Profile a. The stormpipe going up Ajax needs to be in an easement. It will be the responsibility of Gorsuch to maintain but the City requires access in the event of emergency work. b. Is an inlet permitted in the existing Mountain Queen fire access and drainage easement? Is emergency access maintained with the inlet location? This inlet needs approval from Fire Dept and from Mountain Queen per bk 275 pg 378. c. How are the inlets integrated in to the skiway? Is the intent to cover the inlets or block them off from skiers? 31. Sheet C.5.00 a. A drywell detail is shown. Is a drywell proposed on the site? If not remove the detail. 32. Final Plat of: Gorsuch Haus PD/Subdivision Dedications and Reservations a. Numbers 7 and 8: i. In addition to lots 1 and 2 receiving an easement for onsite storm and drainage infrastructure, an easement should be granted for the City to access the drainage infrastructure that takes runoff from Ajax mountain for any maintenance necessities. Item 8 gives the utility owner (the city for stormwater) an easement. Include language so it is clear the easement includes sub surface infrastructure and above grade swales and sheet flow. b. Number 2 i. The Public Trail Easement connecting S Aspen St to Monarch St should be a minimum of 8 ft. A 5 ft public easement is proposed. ii. The dedication states “owner reserves the right to unilaterally re-align this public trail easement.” The City of Aspen needs to approve any alteration to a public trail easement. It cannot be done unilaterally. c. Number 5 i. The dedication states “such private access easement does not confer any rights to the general public, and no public access is intended to be created by this dedication;” The Engineering Department supports pedestrian and bicycle public access to Summer Road. 33. Final Plat of: Gorsuch Haus PD/Subdivision Sheet 4 of 4 a. The sheet shows a temporary construction easement in the ROW. This line should be removed in the ROW. Construction uses in the ROW shall follow section 21.12.140 of the Municipal Code. b. Provide an easement for access to the swale and inlet on the west side of the property. There is concern about the accessibility of the swale and inlet for maintenance. Is the intent to drive around the building to access the inlet? Due to the unusual difficulty to access, the inlet will require a revocable encroachment license and will be the responsibility of the Gorsuch Haus to maintain. Additionally, an easement shall be provided up the summer road and around the building in the event the city needs access the swale and inlet.