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PC Minutes 1-21-20CHANHASSEN PLANNING COMMISSION REGULAR MEETING JANUARY 21, 2020 Chairman Weick called the meeting to order at 7:00 p.m. MEMBERS PRESENT: Steve Weick, Mark Randall, John Tietz, Michael McGonagill, Doug Reeder, and Laura Skistad MEMBERS ABSENT: Mark Undestad STAFF PRESENT: Kate Aanenson, Community Development Director; Bob Generous, Senior Planner; MacKenzie Walters, Associate Planner; and Erick Henricksen, Project Engineer PUBLIC PRESENT: Jessica Galatz HCRRA PUBLIC HEARING: CONSIDER A REQUEST FOR AN INTERIM USE PERMIT (IUP) AND WETLAND ALTERATION PERMIT (WAP) FOR THE PURPOSE OF REPAIRING LANDSLIDES ALONG A PORTION OF THE MINNESOTA BLUFFS LRT REGIONAL TRAIL. Weick: I will turn it over to Mr. Generous. Generous: And I’ll turn it over to Erick. Henricksen: So the applicant here is going to be proposing, or it’s what we’re reviewing here is an interim use permit, essentially a grading permit. Anything over 1,000 cubic yards of grading or disturbance requires an IUP for grading. The applicant here, and this kind of gives you a brief overview of what the proposed repairs are going to be or what the work is going to be for the area but I’d like to start kind of from the beginning as all things do. The impetus of why this IUP or grading permit came in. Back in 2014 the metro area experienced some real intense rain events. I don’t know if everyone remembers but in June 19, 2014 was a very intense rain event as you can see from some of the precip data that’s given. This event caused flash flood watches and warnings around the metro area. Eden Prairie, our neighbor there to the east experienced precip’s in a one day of about 5 ½ inches which is fairly intense. And then also there were rain events prior to this June 19th event which saturated soils and caused more washout of roads and other kind of, oh sorry about that. Similar damage to areas or damage to the metro area. The Minnesota Bluffs LRT regional trail did experience damage as seen from some of these images. The images on your left here, right here is a drone shot of the south, what we’ll be calling the south repair area. So here’s a landslide. This was taken shortly thereafter the landslide. You can see a tree has fallen and what not. This landslide also caused some damage to the culvert Chanhassen Planning Commission – January 21, 2020 2 that’s located just on the downslope of this landslide here and that conveys stormwater underneath the trail. You can see the concrete headwall is damaged. This photo here was taken in 2019 and then here’s just a photo of the trail that was closed. The Three Rivers Park District closed the trail after this event in 2014. Blocked it off with just some black metal fence. In 2015 there was some repairs, some immediate repairs done to the toe of the slope with the installation of riprap and the applicant or the Hennepin County Railroad Authority secured some FEMA funds for that. This can be considered phase 1. Phase 2 was kind of a larger scope. A larger repair of the areas and that’s basically where we’re at today with our IUP application. Just to give you a better understanding of the project area, we’re located, this failure happened on the trail in the south end of, or the south side of Chanhassen. The LRT regional trail bisects Chanhassen as seen here with the red line. Connects Eden Prairie to Chaska. It’s basically a bicycle highway. It’s a main route in the area which has been out of commission due to these failures. The applicant has proposed two access routes to these construction areas or the grading areas. One would be from Eden Prairie. Accessing the trail Eden Prairie about right here I believe it’s called Highview Court or Highview Road. Access via the trail to the north repair area and then they’re also proposing coordination with Moon Valley Aggregate and the property owner there to access the south repair area. Due to, while these project areas aren’t immediately adjacent to homes they are located and the trail is located kind of sandwiched between some residential development so normal construction hours, which for the city is 7:00 to 6:00 Monday through Friday are going to be adhered to. Also within the area and near the construction limits is a city conservation easement that’s attached to Settler’s West. We have reviewed the plans. They are proposing to delineate that and not cause any disturbance in that area. Get a little more familiar with the construction plans. It’s kind of a busy page here but one of the things to note is a grading permit. The dark black lines are the proposed grades or those are areas where you’re going to be seeing grading occurring. So the repair area you can see is kind of a little bit larger compared to the north repair area. Looking at the north repair area, brief overview would be they’re going to, well here let me point out this area here was one of the landslides or slope failures and this area here was that one photo we saw previously of the landslide. Down at the bottom is the culvert that was damaged but in general you can see kind of with these black lines where the grading will occur. The applicant’s proposing approximately 25,000 cubic yards of grading so there’s a lot of work to be done in this area but the grading would be mainly across the trail here. We can see the slope repair area. There’s some grading here and then the creation of a ditch or a drainage channel and some minor grading over here. To look more closely at the repair areas, so this here in your upper left corner is a plan view of the north repair area and below that is a profile view. The plan here is to repair the north landslide with some riprap. Fill it in as you can see again on the profile and then re-establish grades here. They’re proposing a 1 ½ to 1 grade. They will be capping so here is a stormwater conveyance pipe that travels under the trail at this north repair area. They’ll be capping and filling this and abandoning this stormwater pipe with the intent of, if we then look to the right here horizontally drilling a new stormwater conveyance pipe to then enter into a drainage channel with check dams and then it would enter into the south repair area. Essentially if I back up a slide. The stormwater would come from Settler’s West, under the trail and then be routed essentially to this culvert area. So what they’re doing is going to just be re-routing that drainage south here. One of the things that Chanhassen Planning Commission – January 21, 2020 3 we’ve conditioned on this permit is to see some photo analysis on the drainage channel, especially as it comes to hydraulic calculations and looking at the sizing of their energy dissipation devices so at the drainage channel they’re going to be using rock check dams which have been proposed to be evenly spaced at about every 50 feet. There is a slope within this area that gets a little steep and we just want to ensure that the repair methodology that they’re using once installed doesn’t necessarily degrade or cause further erosion or any other kind of environmental impacts of that sort so that’s one of the conditions there. Also when they do the directional drilling here they will be putting a tracer wire on it per city specifications so that way in the future we can locate that if necessary. Or the applicant or the owner of this system can. Looking more at the south repair area where I would say a majority of the grading will be occurring, the intent here is to stabilize this slope. In order to do that what they’re going to be, what they’ve proposed is to lower the grade of the trail approximately 10 feet and some locations 10 to 12 feet. Maintaining a 5 percent slope so again up here is the plan view and then below that is the profile view to kind of give you a perspective of how far they’re going to be dropping the trail. This is one of the reasons is to draw the slope here to a 2 to 1 so something a little more gradual in order to maintain slope stability. To our right here you can see cross sections of the trail kind of right above Station 600 and 650 so kind of right above where they’re doing most of the cutting. So you can see there’s going to be quite a bit of removal and then the slope will be stabilized with some reinforced matting. And then here’s just kind of another view to show the extent of lowering the trail. Grading out the steep slopes and getting that kind of 2 to 1 max all the way down to again this existing culvert. Additional improvements that they’re proposing is to remove the damaged concrete headwall to this culvert and install the flared end section. Do some riparian restoration to the stream here. They’re going to be installing some of these rock veins or essentially check dams for anticipation and then they’ll also have a stilling basin here to accomplish kind of the same task there. Essentially that’s an overview of the project. Kind of how we, or how they came to this point through the storm events and the kind of looking at the overall plan of attack to do the repairs and open the trail back up. Generous: Well the staff is recommending approval of the interim use permit to permit the grading and excavation of this site to repair the sloughing, subject to the conditions in our staff report and adoption of the Findings of Fact and Recommendation. Aanenson: Bob were you going to go through any of the findings or the conditions of the grading permit at all or just? Generous: Well they, the main thing is that all the improvements they’re doing are to improve the condition of the site. We’re trying to re-open the trail facility and to do that they have to clean up this area so. Henricksen: I think one of the conditions that kind of diverge from your typical IUP or grading permit is the applicant will have to enter into a maintenance, operation and maintenance kind of agreement with either the city or the watershed district. These aren’t city owned utilities or infrastructure or anything of that matter. We’re only issuing a grading permit to get the Chanhassen Planning Commission – January 21, 2020 4 restoration completed. There is concern that in the future if there’s any, you know with any kind of storm utility for instance that horizontally drilled pipe or when you’re looking at installing improvements to a drainage channel with basins and check dams you know those kind of things do have to be maintained so one of the conditions that are within this permit and the findings here would be to have that executed agreement with the applicant and either again the watershed district or the City for a clear understanding on who’s going to be maintaining operating those improvements. Most of the other conditions I think are pretty straight forward when it comes to grading, the time of operations, the haul routes. There is some encroachment if you see here on the construction limits on the south repair area where they’re going to be going into the Moon Valley Aggregate site so temporary construction easements of that sort would have to be executed and provided to the City prior to any kind of issuance or notice to proceed on this operation. Are there any others that stand out? Generous: No and again it’s the slope restoration will create stormwater improvements that should improve the conditions that are out there right now. It’s a net benefit for the community to have this. Aanenson: I guess what I was looking for was what Erick had just answered just for your edification so as part of the grading permit they manage the traffic, the hauling routes. Those are all part of the permit that would be administered too. Henricksen: Yep and that initial erosion control inspection would be called into the City to review typical to again any grading operation of this size erosion control measures have to be installed. Your typical BMP’s. From review of the plans they meet our standards and as always adaptive management moving forward on, if more measures are needed you know it’s something that we continue to review and inspect as it is in the city of Chanhassen. Weick: Great, thank you. Questions for the City at this time on what you just heard? Reeder: Mr. Chairman. Weick: Yes. Reeder: I think you heard you say that the trail will go down by 10 feet. What does that do for the people that are trying to use the trail? What kind of slope are we going to have? Henricksen: They’re proposing a 5 percent slope over the lowered section so that’s consistent with ADA requirements. When you’re looking at regional trails I believe 5 percent. I believe you might even be able to go up to about 8.33 percent over a certain amount of distance but as proposed it’s within your requirements for ADA so. Reeder: Okay. Chanhassen Planning Commission – January 21, 2020 5 Henricksen: If you looking at this profile you kind of see it and you’re like well that looks pretty steep. It’s just because of the horizontal scale that’s given to this so this is over I believe 700 feet. 800 feet that this lowering is occurring. Actually I correct myself. I believe it’s 1,200 feet so it’s over quite a long distance that. Reeder: That’s what I couldn’t figure out from this. Okay. McGonagill: Erick on the, so the owner will be the regional trail authority at the end of the day when you talk about maintaining this if I’m looking to who is listed as the applicant, who will be the owner? Henricksen: The applicant for this IUP is the Hennepin County Railroad Authority. After conversation with the applicant I believe the intent is to transfer ownership of these improvements to Carver County, although I would defer that kind of to their, what they are looking for. In regards to meeting that requirement on the permit on who to enter into that agreement at this time it would be the Hennepin County Railroad Authority. Any transfer of that ownership and maintenance would then have to follow up with an update to that maintenance agreement entered into with the City or the watershed district. McGonagill: Okay. One more question. You’ve done a lot of work to take care of what I’d call surface issues. You did a lot of surface grading’s. Surface lowering. And that’s reflecting the surface conditions. What do you know about the sub-surface conditions? Have any soil borings been taken along this to know you know is this just a fluff sitting on top of clay that when it gets saturated it’s going to move again? You know you’re not going to be able to hold it. You know what can you tell me if anything about that along that profile, what are we looking at? Is it kind of like, to use a paraphrase is it an avalanche that’s just going to happen someday? Continue to go on from that. Henricksen: The applicant along with their engineer, Barr Engineering conducted over the course of I believe 3 or 4 years subsequent borings to kind of do this analysis. They did a slope stability assessment and kind of went through all the different alternatives to kind of land on this one. I think that also was coordination with FEMA in regards to scope of work and the funding so they have quite a few borings that were provided to the City. The City after review of kind of their approach and looking at the sub-soils you know find that as far as soils, or slope stabilization to meet your standards and what’s expected when you’re doing this type of work. Our major concern would be the new drainage channel that’s being constructed and the stability of that with an energy dissipation devices and kind of looking at a 10 year event or some event that to ensure that that’s installed and corrected. Some of our review regarding the toe of the slope is recommendations from our report but I know the applicant is kind of confined to what FEMA and their engineers did on their review and then what Barr Engineering did on their review as well. One of the other things that was found I believe in one of the soil borings I think in 2015 or 16 was that there were some contaminated soils that were found. This is kind of one of those rails to trails trail so it was a railroad at one time so it’s fairly typical to find the type of Chanhassen Planning Commission – January 21, 2020 6 contamination that they did. They quantified that at about I want to say 2,500 cubic yards which they’re going to haul off site and dispose of at a landfill but I mean borings and a slope stability analysis was provided. McGonagill: So when they did that slope stability, I mean if you can just kind of summarize it? Is it fairly pinned in? Is it, is it fragile? I’m trying to think of the right words because when I worked this in other areas and you kind of look at it and it says well if they have a really good saturated it’s going to move you know or it’s not. You know that’s kind of where, that’s where my question’s going. Henricksen: Right we, our department after review of their study and their conclusions we found were reasonable. To get into the I think the nitty gritty of you know they show you their mora circles and their cohesions and all of that but to get into the nitty gritty of that I would probably defer that to their engineer as well. McGonagill: Okay thank you Erick. Weick: Any thoughts down there on the end Commissioner Tietz. Looks like you might be brewing something. Tietz: Just scrolling through… Weick: Alright. Fair enough. I just have one super minor clarification but on page 5 when we’re talking about tree height, it’s noted as 6 inches and larger. Should that be 6 feet? Henricksen: So that’s, DBH is the diameter at breast height so that’s, you’re looking at a 6 inch diameter tree. Weick: Diameter, got it. Henricksen: And it’s a certain distance from the ground and that defines it. Weick: I was confused on that, thank you very much. Other silly questions from the commission. Better questions would be even better. Alright with that then thank you Erick and Bob. Would invite the applicant to come forward and tell us about the project. Jessica Galatz: Thank you Chair and commission. My name is Jessica Galatz. I work with Hennepin County, specifically the Hennepin County Regional Railroad Authority and I’d like to introduce Brent Turro with Barr Engineering is the project engineer on this. Brent Turro: Project Manager. Chanhassen Planning Commission – January 21, 2020 7 Jessica Galatz: Project Manager from our engineering consultant. I’m happy to answer any questions. I think Erick and Bob did a great job explaining this project. As you all know, I don’t know if any of you are avid trail users but this trail has been closed since 2014. It’s been quite a rollercoaster ride trying to get it repaired. We worked with FEMA for several years and then one of the questions from Commissioner McGonagill was who is going to own this property. A couple years ago we identified a funding program through Met Council and we can sell this segment of the corridor to Carver County so we’ll sell the corridor to Carver County and then those proceeds will be used for the project repair. So ultimately. McGonagill: …Carver County. Jessica Galatz: Yep everything from the county line to the end of our current ownership in Chaska. So it’s about 3 miles McGonagill: Oh okay. So it’s a good section. They’re not just buying this. They’re buying a lot of it. Jessica Galatz: Yep and I’ll be honest this has kind of been our goal for a while. I think when we bought this corridor Carver County didn’t have a regional railroad authority or didn’t have, wasn’t in place long enough to take on this ownership so we bought the 13 mile long corridor in one piece in 1990 and now we’re trying to convey it to the county that it’s housed in. So they’ll be the ultimate owner. We are working with them and the watershed district right now on that maintenance agreement so we’re all in the know about what the expectations are in the future to maintain that new drainage channel. I don’t know if anyone else has any questions we could answer. McGonagill: Well let’s go back to my question on the slope stability. You know with Barr. It’s more looks like the subsurface geotechnical that you’re dealing with. Brent Turro: So you want me to just give you an overview of what we found? McGonagill: Yeah. Brent Turro: So in general the embankment is a sandy clay soil. It’s a mix of maybe natural clay soils or soils that were cut as the rail corridor was built and then used as embankment fill, particularly in this stretch. Below that is some siltier surface soils but then as you get down into it it’s mostly sand. So slope stability we assess through looking at different alternatives. One alternative was to keep the trail grade where it is and move the embankment slopes out required a lot of fill. It’s ultimately more expensive as well. This concept would require, I shouldn’t say require. This concept would be to take the trail grade down further and then reduce the slopes. That improves the slope stability so we did the analysis where we targeted standard factors of safety for trail embankments along transportation or other infrastructure corridors and our analysis satisfies those factors of safety. And that’s really the gist of it. Chanhassen Planning Commission – January 21, 2020 8 McGonagill: Okay. I notice they’re using flexi mat. Is that what you’re putting in the drainage channel? Brent Turro: Correct. McGonagill: Yeah I’ve just used that in a previous life. It will stay. It’s a good product. It doesn’t move. Brent Turro: Okay, good to hear. McGonagill: Once you get some growth around it you’re pretty well, you’ll pin it in. Brent Turro: Okay, yeah good to hear. We considered that and upon recommendation from the County here they had used on previous projects so. McGonagill: Yeah I’ve used it on some really bad soils and just give it a couple, you know over seed it a lot and give it a couple years and you’ll be good. Brent Turro: Well that’s good to hear. Weick: We’ll have to leave that note for Carver County. McGonagill: There you go. Weick: Is the trail fenced at all in that area to keep people on the trail? Jessica Galatz: Yes I believe when the trail was built it had a fence running along both sides because both sides of the trail are pretty steep in that area. Weick: Okay. Jessica Galatz: And those are still in place although at the specific location of the south failure not all the posts are still in place. Weick: Okay. Jessica Galatz: And then we’ve added fencing at both ends of where we’ve closed the trail to fence it off from public use. Weick: Right. So that fence will be repaired then and reinstated. Jessica Galatz: Certainly, yep. Chanhassen Planning Commission – January 21, 2020 9 Weick: Okay. Jessica Galatz: So there will be some repair to the trail as part of this project. There was damage to the trail in the 2014 storm event and then just over the last almost 6 years of not getting in there to maintain the trail regularly nature has kind of taken back so that will be included in the project. Weick: Okay. Good down there? Questions. Okay well thank you very much and thank you for helping us understand the project a little more. Jessica Galatz: Okay. Weick: With that I will open the public hearing portion of tonight’s event. Anyone wishing to come forward please do so at this time. And seeing nobody come forward I will close the public hearing and open the item for Commissioner discussion. Seems to me you know hallelujah, this is one of those where. Randall: It’s very well planned out. Weick: Yeah. Randall: It’s obviously engineered well and they know what they need to do so. Weick: Yeah it will be nice to have this open. Tietz: Having biked that for many years I’m looking to it getting back into shape. It was such a beautiful trail down to Chaska and some of those overlooks were spectacular down at the bottom so it will be good to get it back. Weick: I certainly would entertain a motion if there was no further discussion on the item. Tietz: I’ll make a motion. Weick: Thank you. Tietz: The Chanhassen Planning Commission recommends the City Council approve the Interim Use Permit Planning Case 2020-01 to permit grading, excavation and slope restoration as proposed in the plans prepared by Barr Engineering Company dated 12-13-2019 subject to the conditions of approval an adopt the Findings of Fact and Recommendation. Weick: Thank you Commissioner Tietz. We have a valid motion. Do we have a second? Chanhassen Planning Commission – January 21, 2020 10 McGonagill: I’ll second it. Weick: We have a second from Commissioner McGonagill. Any interim discussion before we vote? Seeing and hearing none. Tietz moved, McGonagill seconded that the Chanhassen Planning Commission recommends the City Council approve the Interim Use Permit, Planning Case 2020-01 to permit grading, excavation and slope restoration as proposed on the plans prepared by Barr Engineering Co., dated 12/13/2019, subject to the Conditions of Approval and adoption of the Findings of Fact and Recommendation. 1. The interim use permit shall be approved for a period of two (2) years from the date of City Council approval. The applicant will need to request a formal extension 60 days prior to the expiration date of the interim use permit. 2. Permits from the appropriate regulatory agency must be obtained; including but not limited to the Minnesota Pollution Control Agency, Lower Minnesota River Watershed District and Carver County. 3. The applicant must provide the city with a cash escrow or letter of credit in the amount of 110% of the construction costs for the appropriate phase of the grading operations to guarantee erosion control measures, site restoration, and compliance with the interim use permit. 4. Documentation and/or load tickets from the approved waste disposal facility where contaminated soils will be disposed of shall be provided to the city. 5. All required ROW permits, access agreements, and temporary construction easements shall be secured prior to the commencement of any construction activities. 6. All oversize/overweight loads leaving the site to the east must apply for County Transportation OS/OW trip permits. 7. Permitted hours of operation will be 7:00 a.m. to 6:00 p.m., Monday through Friday, and 9:00 a.m. to 5:00 p.m. on Saturday with no work permitted on Sunday or legal holidays. 8. If any excess material is hauled to another site in Chanhassen, a separate grading permit will be required for the other property. 9. The applicant shall schedule a walk-through of the site with city staff to review boundary staking and removals of edge trees prior to any activity commencing. 10. The applicant shall identify conservation easement boundary on site. Vegetation within the easement may not be irrevocably damaged by construction activities. If irrevocable damage Chanhassen Planning Commission – January 21, 2020 11 is caused, the applicant shall be responsible for replacement plantings at a rate of 2:1 diameter inches. 11. Applicant shall report tree removal quantities to the city. 12. Upon completion of the installation of initial erosion control measures, the contractor shall contact the city’s Engineering Department (Ryan Pinkalla, 952-227-1173) for an initial erosion control inspection prior to grading operations. 13. HDPE pipe installed shall be furnished with tracer wire meeting the City of Chanhassen’s Standard Specifications. 14. The applicant shall submit hydraulic design calculations and follow-up analysis for the newly proposed stormwater conveyance system, including analysis for riprap stilling basins and rock check dams as energy dissipaters. 15. One hundred percent (100%) construction plans shall be provided for review and approval prior to commencement of any construction activities. 16. The applicant shall enter into maintenance agreements with the city and/or Lower Minnesota River Watershed District to ensure maintenance responsibilities and ownership are the responsibility of the HCRRA or their designee, in perpetuity, prior to commencement of any construction activities. 17. The applicant shall provide further justification to the wetlands being impacted being incidental. This can be accomplished through the WCA permit process that is currently underway. All voted in favor and the motion carried unanimously with a vote of 6 to 0. Weick: The motion passes unanimously 6 to 0. McGonagill: Get her done. APPROVAL OF MINUTES: Commissioner Skistad noted the verbatim and summary Minutes of the Planning Commission dated December 3, 2019 as presented. ADMINISTRATIVE PRESENTATIONS. CITY COUNCIL ACTION UPDATE. Aanenson: Thank you. Since we haven’t met since the last meeting was December 9th. The last time the City Council met of last year so I’ll kind of give you an update on that. The City Council did grant Avienda an extension of their grading plat permit. We do have a meeting set up here in the next week to meet with them and see where they’re at and get things rolling. I