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HomeMy WebLinkAboutKECHTER CROSSING - Filed GC-GENERAL CORRESPONDENCE - 2014-08-28Randy Maizland - RE: FW: Kechter Crossing _ Page 1 From: "JONS" <jons@jimselldesign.com> To: RMaizland fc ov.com; m ohnson larimer.or ; jons @ g j @ g @jimselLdesign.com Date: 7/30/2008 1:15:42 PM Subject: RE: FW: Kechter Crossing Thanks Matt - it does seem like the quickest/least painful option - I have asked Lester how long it will take him to put this together and am waiting for a response. -----Original Message ----- From: Matthew Johnson [mailto:mjohnson@larimer.org] Sent: Wednesday, July 30, 2008 12:54 PM To: 'Randy Maizland'; Jon S Subject: RE: FW: Kechter Crossing Jon - After re -reading the previous emails, etc it seems Randy's option 2 (supplemental report from Lester,etc) is the next viable step. Let me know if that's all you need from me at this point. matt >>> "JONS" <jons@jimselldesign.com> 07/29/2008 8:10 AM >>> Matt/Randy - we all went round and round on this groundwater separation issue for Kechter Crossing back in January. Not sure how it happened, but the client and potential buyer were under the impression that the separation was T and not 5'. 1 am hearing that the deal between them is likely to fall apart due to this issue and I am trying to find a solution. The current comment is: The development agreement and disclosure notice will need to contain conditions to the effect that each lot will require a geotechnical investigation conducted by a professional engineer prior to foundation construction and as part of the investigation, depth to groundwater shall be determined. The condition will need to include language that basements will not be allowed if the lowest floor (basement) elevation is within 5 feet of the groundwater surface. I would consider this a dead issue, but Lester has told me that he feels a 3' separation is reasonable. The only option that I can see worth exploring at this point is what Randy wrote in the attached e-mail: 2. Provide a geotechnical supplement report to the original soils report that provides specific recommendations for maintaining a min. 3' separation between basement finish floor elevation and ground water elevations. If this option is preferred, the plans will need to identify on a lot by lot basis what the proposed basement FF elevation will be and what the anticipated ground water elevation will be (or this can probably be done with a table of lots and elevations). The supplemental report will also need to address potential fluctuations in ground water elevations due to seasonal, historic and developed conditions (irrigation affects etc..). The report will also need to clearly state that it is the engineers opinion that if a 3' separation is maintained, a subdrain system will likely not be needed and Randy Maitland - RE: FW: Kechter Crossing _ Page 21 there is low potential for flooding or need for a subdrain system to mitigate the affects. Please let me know if this is still and option and I will coordinate with Lester at EEC to get his take on the situation. Thanks - sorry to bring this issue back up again. Jon -----Original Message ----- From: Randy Maizland [mailto:rmaizland@fcgov.com] Sent: Tuesday, January 22, 2008 1:26 PM To: Jon S; 'Matthew Johnson' Subject: RE: FW: Kechter Crossing I apologize if I'm not being entirely clear in my response. It's not quite black and white issue. I have discussed this issue exhaustively in the past with the Stormwater section and my supervisors. Because this project will eventually be annexed into the City, the following two sections of the LCUASS standards and City Code should apply: City Code section 3.3.3 (C) - No building lots should be platted if there is an anticipation or potential that basement flooding may occur due to high ground water unless properly mitigated (i.e subdrain system). LCUASS Section 5.6.1 - If groundwater is predicted to be encountered within 5' of existing or proposed finish grade, a subsurface water investigation is required to ensure mitigation of effects on the public ROW improvements. - The City would consider a subdrain system that discharges excess water over a sidewalk or into the gutter a potential negative impact to the ROW improvements. What the City would like to avoid is a situation where there is known shallow groundwater that has the potential to flood basements or the need for a subdrain system that has not been designed properly prior to plan approval. The Building department at the City does NOT analyze groundwater issues in the building permit review process due to liability concerns. Therefore, the issue of shallow ground water needs to be addressed in the entitlement, platting, site construction review process prior to building permit issuance. This issue with Kechter Crossing can be addressed a few different ways in my opinion: 1. Provide a hydrological study with complete recommendations for basement construction and subdrain system construction with an outfall that does not impact the ROW (no flows over sidewalks). Show on the plans how these recommendations will be implemented and provide a design for any subdrain system that will not negatively impact the ROW. 2. Provide a geotechnical supplement report to the original soils report that provides specific recommendations for maintaining a min. 3' separation between basement finish floor elevation and ground water elevations. If this option is preferred, the plans will need to identify on a lot by lot basis what the proposed basement FF elevation will be and what the anticipated ground water elevation will be (or this can probably be done with a table of lots and elevations). The supplemental report will also need to address Randy Maizland - RE: FW: Kechter Crossing _ Page 3 potential fluctuations in ground water elevations due to seasonal, historic and developed conditions (irrigation affects etc..). The report will also need to clearly state that it is the engineers opinion that if a 3' separation is maintained, a subdrain system will likely not be needed and there is low potential for flooding or need for a subdrain system to mitigate the affects. 3. Design without basements or maintain more than 5' between proposed FF basement elevation and ground water. I hope this provides you with a better idea of what the City needs and why. I'll be glad to discuss in more detail if needed. I can be reached at 970416-2292. Randy Maizland >>> "JONS" <jons@jimselldesign.com> 1/22/2008 11:36 AM >>> I can pretty much guarantee that some of the basement elevations will be within 5' of groundwater. Can you give me a 100% answer on if a hydrological report will be needed? I know you pretty much did, but I hear a little room for discussion - I just need to know if I should get this report started. Thanks Randy -----Original Message ----- From: Randy Maizland [mailto:rmaizland@fcgov.com] Sent: Tuesday, January 22, 2008 11:13 AM To: Jon S; 'Matthew Johnson' Subject: RE: FW: Kechter Crossing I guess my initial response is that since the basements will be within 5' of groundwater the City should be provided with the hydrological study and recommendations by EEC. If the recommendations in the report are that no subdrain systems will be needed then I don't think we really need to see anything on the plans however, if a subdrain system will or may be needed or it will need to be determined during construction, we'll need to see that subdrain design prior to plan approval and we'll also provide language in the development agreement regarding the need or possible need for subdrain systems. It does not appear that the detention pond/groundwater relationship will be a concern except from a constructability standpoint but it should be addressed in the report with recommendations for construction of the pond. I am going to consult with our Stormwater guys to confirm this. If you want to add notes to the grading plan that would not be a problem at all ... based on and reinforcing the recommendations from the report. Randy Maizland >>> "JONS" <jons@jimselldesign.com> 1/22/2008 10:48 AM >>> Matt/Randy - I have been talking with the client and Lester at EEC and reviewing our final grading versus the groundwater depth as described in Lester's report. The bottom of the detention pond comes within about a 4' minimum to the Randy Maizland - RE: FW: Kechter Crossing Page 4 groundwater in one area. This doesn't effect ROW improvements. Lester suggested that 4' should be ok, but did note if it gets much closer, scrapers might have problems during construction. On the basement issue - Lester suggested that if a 3' separation can be kept between the groundwater table and the basement elevation we shouldn't need under drains, perimeter drains, sump pumps ... ect. We have worked up top of foundation elevations and with a little tweaking can raise all basement elevations to this 3' clearance. This being said - I need to know what the City/County needs for their comfort level. Personally I would want to add notes to the final grading plan stating the minimum distance between groundwater and basement elevations for my protection, but will you guys also be interested in seeing notes on the plat or a specific letter/report from Lester putting some of this in writing? Thanks, Jon -----Original Message ----- From: Matthew Johnson [mailto:mjohnson@larimer.org] Sent: Friday, January 11, 2008 4:21 PM To: Jon S Cc: Randy Maizland Subject: Re: FW: Kechter Crossing Hi Jon, LCUASS Section 5.6.1 requires a subsurface water investigation when groundwater is within 5 feet of the ex. or proposed ground surface. This standard is mainly to ensure that ROW improvements are not impacted. Your prelim report showed groundwater at the 8 to 12 foot depths so depending on the proposed finished grades, you might exceed 5 feet throughout the site and a report wouldn't be necessary based on 5.6.1. However, basements generate additional concerns as Randy indicated. A report would then be beneficial despite the possibility (on this site) of the actual ground elevation being more than 5 feet above the groundwater levels. In this case, it sounds like basement floors will in fact be at/near groundwater levels. Somewhat of an investigation is likely necessary to compare the potential basement floor elevations to the probable groundwater elevation. Having said that, I will pose the following question to you (basically reiterating what Randy indicated) in effort to determine if a report should be prepared: - If you are anticipating any basements in areas where the sump pump will be in frequent use and/or a subdrain system (serving multiple lots) is necessary, then a report and plan should be prepared/submitted for review. Also, maybe EEC can help in this determination. Section 5.6 goes on to give the submittal requirements for the report. Hopefully, this all makes sense. Feel free to respond with any questions. Thanks, matt Randy Maizland - RE: FW: Kechter Crossing Page 5 498-5724 >>> "Randy Maizland" <rmaizland@fcgov.com> 01/11/2008 1:50 PM >>> Hello Jon, If basements are proposed and there is a groundwater issue that may require an underdrain system, we will need to see the report and design prior to final approval and entering into a development agreement. We would provide specific language in the development agreement regarding the underdrains. We have had some problems recently with sump pumps that continuously discharge water leading to saturated yards and nuissance water running over public sidewalks .... algae, mosquitos in the summer, icing in the winter. This unfortunately cannot be handled on an individual case by case, building permit basis. I'll be glad to discuss this with you in more detail if you like. You can reach me at 970-416-2292. Thank you, Randy >>> "JONS" <jons@jimselldesign.com> 1/11/2008 1:32:38 PM >>> Randy - I got a message from Matt Johnson that you have some concern about the groundwater issue at Kechter Crossing. I talked to Lester at EEC about this in the past and his response is attached. I have assumed that this would be taken care on an individual lot basis at building permit or time of construction and that any perimeter drain or sump pump would discharge on the lot. Sounds like this issue needs some more attention right now and maybe a hydrologic report is necessary to make sure a subdivision wide underdrain is or isn't necessary. Please let me know if you are requesting this report and if this would hold up a final submittal. Thanks Randy, Jon From: Lester Litton [mai Ito: LesterL@earth-engineering. com] Sent: Wednesday, December 05, 2007 2:02 PM To: Jon S Subject: RE: Kechter Crossing The comment from the County looks like they are considering individual systems. I believe the extent of the individual system may vary throughout the site based on observed groundwater depths at the individual units as well as the individual unit designs. A ranch with groundwater at 8 feet may not be a concern but a 10 foot basement with 8 feet to groundwater would. It may be a little late in the process but site grading can be used to establish greater separation from groundwater and reduce the complexity of individual systems in shallower groundwater areas. If appropriate, an area wide drain system could be developed to lower the ground water table and provide a discharge for the individual home drains. The trick for an area wide system is typically finding suitable gravity drainage as I would assume is the case for this property. That system may only encompass a portion of the property. Randy Maizland - RE: FW: Kechter Crossing Page 6 Let me know if I can be of further help (assuming I was of any help to start). Lester lesterl@earth-engineering.com From: Jon S [mailto:jons@jimselldesign.com] Sent: Monday, December 03, 2007 2:49 PM To: Lester Litton Subject: Kechter Crossing Lester - Kechter Crossing (Proj # 1052130) is heading toward final design. I have the following comment from the County: 1. Based on the Geotechnical Report, groundwater was present at 8 to 12 foot depths below grade throughout the site during testing. As a result, basements may not be feasible for various lots throughout the site. Therefore, a note needs to be provided on the plat stating that an engineered footing and foundation design along with an appropriate subsurface drainage system design is required as part of a building permit application for all lots in the development. I have been assuming that these would be individual perimeter drain systems daylighting on the lots or in sumps and we are not really talking about a subdivision wide underdrain system collecting all lots and dumping into the detention pond. Please let me know your take on this issue. Thanks Lester, Jon Jonathan Sweet, P.E. Jim Sell Design, Inc. 153 West Mountain Ave. Fort Collins, CO 80524 Office: (970) 484-1921 ext. 22 Cell: (970) 412-2302 Fax: (970) 484-2443 <file:///\\www.jimselldesign.com> www.jimselldesign.com Randy Maizland - RE: FW: Kechter Crossing Page