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2. Paulsen supplement 18558 Langly 11-18-22From: Tom Langer Sent: Wednesday, October 26, 2022 11:26 AM To, Frank Brodeen Cc: Richard Paulsen; Shawn Kupcho Subject: RE: 2020-11411_Paulson Residence (18558 Langly Ave N) - Revised Rain Garden Location - Drainage Overview Map Hi Frank, Two items that are needed will be cross sections of the two stormwater features and buffer monument locations. I have attached versions that can be directly incorporated into the plans. Buffer monuments will need to be installed (can be after construction) and their locations called out on the site plan. A buffer monument can be either a ground flush iron rod or another form of declaring signage denoting the buffer and conservation of the area. The buffer monuments will need to be placed at lot lines and at least every 200 ft across the green line or at any major change in direction. The last watershed item will then be declaration agreement for buffer and SW management. Once Richard confirms the project has been approved by the City, I will work with him complete a declaration for recording followed by issuance of his Amended watershed permit. For now, I have attached the template we will be using for this. Thanks! Tom Langer Riparian Permit Specialist I Carnelian Marine St. Croix Watershed District 11660 Myeron Rd North I Stillwater, MN 55082 Phone: S j651) 275.74521 Cell: 507.276.8056 8 www.croscwd.org From: Frank Brodeen <Frank:Brodeen@widseth.com> Sent: Tuesday, October 25, 2022 4:30 PM To: Tom Langer <tom.langer@croscwd,org> Cc: Richard Paulsen <richard cedarwoodmn.com>; Shawn Kupcho <Shawn.Kupcho@widseth _com> Subject: RE: 2020-11411_Paulson Residence (18558 Langly Ave N) - Revised Rain Garden Location - Drainage Overview Map Good Afternoon Tom, Thanks for the comments below. I had a conversation with Jay Riggs regarding the wetland boundary and we have sorted out the confusion, confirming that the red dashed line on our site plan is the correct wetland boundary line. Please see the attached revised site plan and supporting computation documents that address the remaining comments. PROPOSED RAIN GARDEN - NW CARNELIAN I-�` - MARINE - ST. CROIX WATERSHED DISTRICT Small Residential Project Stormwater Worksheet Demonstrating compliance with Rule 2.4.1 for residential projects, including subdivision of less than 4 lots, entailing'/4 acre or less of impervious surface. Project Address 18558 LANGLY AVENUE N, SCANDIA , MN 55047 Determine Water Quality and Volume Control Standard STEP 1: Quantify the Impervious Surfaces[. (a) Existing Impervious: 0 SF (b) Existing Impervious Disturbed: 0 SF (c) Total Impervious (Existing + Proposed): 1,694 SF (d) New & Reconstructed Impervious: 1,694 SF Date 9/26/22 3,997 TOTAL PROJECT IMPERVIOUS, SEE AMENDED SOILS WORKSHEET FOR REMAINING SITE IMPERVIOUS. STEP 2: Will Proposed Activity Trigger the District's Redevelopment Criteria? (Check One) N/A ❑ If (b) > (a) x 50%, then stormwater management is required for all impervious onsite. Use (c) in STEP 3. ❑ If (b) < (a) x 50%, then stormwater management is required for new & reconstructed impervious. Use (d) in STEP 3. STEP 3: Determine the Treatment Volume Requirement. 1,694 (c or d) x 12-a"Inches)2 x (0.9) / 12 = 356 cubic feet (e) 2.8 BMP Selection and Siting STEP 4: Preliminary Identification of Onsite Soils. Identify the Hydrologic Soil Group (HSG) of onsite soils based on the Washington County Soil Survey published by the Natural Resources Conservation Service available online at http://websoilsurvey.nres.usda.gov/app[WebSoilSurvey.aspx or hosted on the District's webmap at https://www.eorinc.io/maps/CMSCWD/. Soils review determines applicable Credit Multiplier in Step 5. The HSG of onsite soils are predominantly: AO B C D ' "Impervious surface" means a compacted surface, or a surface covered with material (i.e., gravel, asphalt, concrete, Class 5, etc.) that increases the depth of runoff compared to natural soils and land cover. Including but not limited to roads, driveways, parking areas, sidewalks and trails, patios, tennis courts, basketball courts, swimming pools, building roofs, covered decks, and other structures. Permeable hard surfaces are considered impervious surfaces but may receive treatment volume credit if designed in accordance with District guidance. Treatment volume requirements may be waived for private drives on residential lots at least 10 acres in size if the drive is bordered downgradient by vegetated open space or a vegetated filter strip with a minimum width of 5 feet and runoff does not discharge directly to wetland, groundwater -dependent natural resource, or public water. z 2.8 -inches if the BMP is located in a buffer (Rule 4.5.2(d)(ii)); 4.2 -inches if the BMP is tributary to landlocked basin (Rule 2.4.1(b)) Emmons and Olivier Resources, Inc - 1 - July 2022 CARNELIAN - MARINE - ST. CROIX WATERSHED DISTRICT STEP 5: Select the Appropriate BMP Design. Treatment volume credit for BMPs is identified in Table 1 on a per unit surface area basis. See companion document, BMP Design Guidance, for specific design criteria required to receive the treatment volume credit identified. Most BMP credits are based on the HSG identified in STEP 4. TABLE 1. BMP Treatment Volume Credit. ` See District Design Details for each practice for specific design criteria to receive treatment volume credit. BMP Siting and Sizing Guidelines: Site BMPs downslope of impervious surfaces in most permeable soils. Site BMPs in HSG A and B soils wherever feasible to maximize credit by providing infiltration of stormwater. Rooftop downspouts provide flexibility to direct runoff to a variety of BMPs. In particular, raingardens must accept rooftop or driveway runoff, where feasible. Emmons and Olivier Resources, Inc - 2 - July 2022 Treatment Volume Credit Multiplier BMP (CF/SF unless otherwise noted) Primary Design Assumptions` Hydrologic Soil Grou HSG A B C D • Shallow surface storage (3 -inches) Amended Soils with 0'4 • Compost -amended soil depth (6 -inches) Depressional Storage • Bulk density testing required unless District staff observes soil amendment process Raingardens • Surface ponding depth of 18-incbes (HSG A, C & D) (Bioretention &2.1 1.8 1.5 1.5 • Surface ponding depth of 15 -inches (HSG B) Biofiltration) • Perforated underdrain (HSG C & D) • 4 -ft channel bottom with 3:1 side slopes 600 CF 500 CF 400 CF 400 CF • 2% channel slope with earthen check dant every 60 Vegetated Swale with /check / check /check / check or 75 -ft based on soil HSG Check Dams dam dam dam dam • Over -excavate 30 in and backfill with engineered planting medium • Perforated underdrain (HSG C & D) Permeable Hard Surfaces • 18 -incites of rock storage Permeable Paver (e.g'' 0.6 0.6 0.4 0.4 18 -inch sand layer required for HSG C and D soils Patio, Porous Concrete Perforated underdrain (HSG C & D) Driveway) Infiltration Trench / 1 2 1 2 0 8 0 8 3 -ft of rock storage French Drain 4 -ft wide ` See District Design Details for each practice for specific design criteria to receive treatment volume credit. BMP Siting and Sizing Guidelines: Site BMPs downslope of impervious surfaces in most permeable soils. Site BMPs in HSG A and B soils wherever feasible to maximize credit by providing infiltration of stormwater. Rooftop downspouts provide flexibility to direct runoff to a variety of BMPs. In particular, raingardens must accept rooftop or driveway runoff, where feasible. Emmons and Olivier Resources, Inc - 2 - July 2022 CARNELIAN - MARINE - ST. CROIX WATERSHED DISTRICT Use TABLE 1 and the BMP siting and sizing guidelines above to fill in the proposed BMP design in TABLE 2 below. TOTAL Treatment Volume Credit (f) must meet or exceed the Treatment Volume Requirement (e). TABLE 2. Proposed BMP's Treatment Volume Credit. COLUMN: A B C D E BMP HSG BMP Surface Area (SF) or No. of Check Dams (No.) Credit Multiplier from Table 1 (CF/SF or CF/check dam Treatment Volume Credit (CF) [Column C x Column D] Example: Raingarden 1 B 200 SF BMP Surface Area 1.8 360 CF RAINGARDEN NW A 170 SF BMP SURFACE AREA 2.1 356 CF TOTAL Treatment Volume Credit (CF) 356 CF (}� STEP 6: Onsite Soil Verification Soil borings are recommended in the locations of proposed BMPs in order to assess the infiltration capacity of the soil as characterized by the hydrologic soil group (HSG). Soil boring results guide the selection of the BMP(s) and helps to ensure the BMP(s) will function properly. In lieu of borings, soil verification may be achieved by review of other applicable data (septic system percolation tests/soil logs, test pits, etc.). STEP 7: Final Siting & Sizing Revise BMP siting and sizing, as necessary, based on results from the onsite soil verification. Return to STEP 5 and revise TABLE 2. Treatment volume must meet or exceed required olume to meet District Rules and be considered for a permit. Does STEP 5 (f) meet or exceed STEP 3 (e) ? Yes No (circle one) TREATMENT VOLUME FOR AMENDED SOILS DOES NOT MEET REQUIRED VOLUME FOR SITES TOTAL PROPOSED IMPERVIOUS. SEE PROPOSED AMENDED SOILS WORKSHEET FOR PROPOSED TREATMENT VOLUME FOR THE REMAINDER OF THE SITE'S IMPERVIOUS SURFACE. Emmons and Olivier Resources, Inc -3. July 2022 Please let us know if you need anything else regarding an amended permit. Thanks! Frank Brodeen Civil Engineer 6$1 35$,-2345 5368 266th Street PO Box 730 Wyoming, MN 55092 WiDSETH W idseth.com 50 Best Places to Work (Prairie Business Magazine, 2022) From: Tom Langer <tom.lanRer@croscwd.ora> Sent: Thursday, October 20, 2022 12:27 PM To: Frank Brodeen <Frank.Brodeen@widseth.com> Cc: Richard Paulsen <richard@cedarwoodmn.com>; Shawn Kupcho <Shawn.Kupcho@widseth.com> Subject: RE: 2020-11411_Paulson Residence (18558 Langly Ave N) - Revised Rain Garden Location - Drainage Overview Map Hi Frank, Lets touch base when you have a minute. Please call my cell. Two main items to update, can you more clearly outline the vegetation restoration plans (5ft buffer in front yard from road to deck, anything behind deck into back yard that is disturbed will need native plantings/seed (call out seed mix/planting plans). There was a lot of discussion this spring and I reconfirmed with Jay Riggs (WCA official) this morning that the current wetland boundary is incorrect. The correct boundary is what is currently labeled as Edge of Water in your sight plan. This will significantly reduce the wetland footprint and the associated buffer. Thanks, Tom Langer Riparian Permit Specialist I Carnelian Marine St. Croix Watershed District 11660 Myeron Rd North I Stillwater, MN 55082 Phone: s 651 275-7452 I Cell: 507.276.8056 a www.croscwd.org From: Frank Brodeen <Frank.Brodeen@widseth.com> Sent: Wednesday, October 19, 2022 9:17 AM To: Tom Langer <tom.laneer@croscwd.ore> Cc: Richard Paulsen <rchard@cedarwoodmn.com>; Shawn Kupcho <Shawn.Kupcho@widseth.com> Subject: FW: 2020-11411—Paulson Residence (18558 Langly Ave N) - Revised Rain Garden Location - Drainage Overview Map Good Morning Tom, Just following up on the email below regarding the Paulsen Residence at 18558 Langly Ave N. I know you were on vacation last week so I'm sure you are busy catching up on things this week (always a hole to dig yourself out of after a vacationl) but just wanted to touch base on the below and attached. Feel free to give me a call if anything needs to be discussed or if you have any direction on what the next steps are. Thanks, Frank Brodeen Civil Engineer 651-358-2345 5368 266th Street PO Box 730 Wyoming, MN 55092 WiDSETH Widseth.com 50 Best Places to Work (Prairie Business Magazine, 2022) From: Frank Brodeen Sent: Tuesday, October 11, 2022 11:24 AM To: Tom Langer <tom.lanRer@croscwd.ore> Cc: Richard Paulsen <rchard@cedarwoodmn.com>; Shawn Kupcho <Shawn.Kupcho@widseth.com> Subject: RE: 2020-11411_Paulson Residence (18558 Langly Ave N) - Revised Rain Garden Location - Drainage Overview Map Good Morning Tom, Thank you for the feedback and comments below. We have reviewed and addressed the comments below into our proposed drawings. Please see the attached revised certificate of survey drawing, rain garden and amended soils computation sheets, and a drainage overview map. We believe these revisions address the comments listed below. Please feel free to reach out with any questions on the attached. Thanks, Frank Brodeen Civil Engineer 651-358-2345 5368 266th Street PO Box 730 Wyoming, MN 55092 WOSETH Widseth.com 50 Best Places to Work (Prairie Business Magazine, 2022) From: Tom Langer <tom.langer@croscwd.org> Sent: Monday, October 3, 2022 11:04 AM To: Frank Brodeen <Frank.Brodeen@widseth.com> Cc: Richard Paulsen <richard@cedarwoodmn.com>; Shawn Kupcho <Shawn.Kuacho@widseth.com> Subject: RE: 2020-11411_Paulson Residence (18558 Langly Ave N) - Revised Rain Garden Location - Drainage Overview Map Hi Frank, Thanks for the site visit discussion and continued efforts on this. I have been able to talk with both the District Engineer and Mike to gain greater context to previous discussions and have a few final recommendations that I think help better blend some of the District requirements while alleviating some of the buffer concerns Richard had. 1) Both Mike and Engineer recalled discussing the premise of getting sheet flow across the driveway into the front yard area before the basin. They both feel that utilizing the amended soils with the 3 -inch depressional storage still is a very viable option to gain additional stormwater treatment on site and shouldn't interfere with the intent of the PCA low floor requirements. Then any outstanding difference should be applied to a larger scaling of the proposed rain garden. 2) Ensuring flow: The plans should be clear and ensure that the pitch of the driveway doesn't funnel water right down and back into the street. It should be crowned or angled to aide the sheet flow. 3) The portion of the front yard that gets incorporated into the depressional storage area (3inch depressional area with amended soils) will still require the buffer easement (50ft average and 25 ft minimum), however, given that utilizing this area as the BMP will force the soils to be disturbed (amending process), we will only ask that 5ft from the wetland fringe (rather than all 25 ft) be restore to native plantings in the front yard area (orange area below). The remainder of the front yard buffer can be restored to yard grasses and mowed. All other buffer areas on the side of the home and into the backyard will still be required to go back to native plants and require a native planting plan. Please let me know if these item makes sense or if any clarifications are needed. Overall, I think this will help alleviate some of the initial concerns Richard had with the native planting requirements in the front yard buffer and still allow him to achieve all stormwater and buffering requirements. I've included a screenshot with these comments to assist. Thanks, N8s°5557 ngardeni itlneedi '-'� "; -North line mak[me up remaining iy i' `�'�• i o' Let 7 difterence from a j 5t0R2ter disconnect area. !`--- — }Rai 41'61r3m Pa cvschlf •, octal 1. A• Sacs ; Fd -e ci 4 . (\' Ca.dn Ek.+940.a ,t� Oe�aY �, ��• \ // 6, 7P P7PLp �y�4i!• ` / I tIDl St WE -RW •w 148,42 l \ apllved _ n 056 �.`Noare SAO_.. Eery<L Northeast corner of- ' — "` Lot 7• Block 3 S Tact—Inde � BLISS PLAT FIST DIVISION , •o in t NAU �i ,3- Proposed Drainage —0 ' s and Uaity Eusanwnt e• 7 i Pond 8v 41'61r3m Pa cvschlf •, octal 1. A• Sacs ; Fd -e ci 4 . (\' Ca.dn Ek.+940.a ,t� Oe�aY �, ��• \ // 6, 7P P7PLp �y�4i!• ` / I tIDl St WE -RW East lire of Lot 7 / a.sVM*( rAuk.,Y 0tlLY IrIC / i Pm9&le �rncroadimana ' o / ORs ti boa amen 3 in bemm should be This area ., establishn r> buffer, ho to the stor R native p edge land, J All remaa �? need to be Plants if s1 tine to a. rathe 3 v '1 apllved _ n 056 �.`Noare SAO_.. S Tact—Inde � 'dp ♦ ,, \ t�fC{i000d t�i •o in t NAU �i so \` East lire of Lot 7 / a.sVM*( rAuk.,Y 0tlLY IrIC / i Pm9&le �rncroadimana ' o / ORs ti boa amen 3 in bemm should be This area ., establishn r> buffer, ho to the stor R native p edge land, J All remaa �? need to be Plants if s1 tine to a. rathe 3 v '1 TABLE 1. BMP Treatment Volume Credit. Tom Langer Riparian Permit Specialist I Carnelian Marine St. Croix Watershed District 11660 Myeron Rd North I Stillwater, MN 55082 Phone: Q 651 275-74521 Cell: 507.276.8056 a www.croscwd.org From: Frank Brodeen <Frank.Brodeen@widseth.com> Sent: Thursday, September 29, 2022 10:25 AM To: Tom Langer <tom.langer@croscwd.ors> Cc: Richard Paulsen <richard@cedarwoodmn.com>; Shawn Kupcho <Shawn.Kupcho@widseth.com> Subject: 2020-11411—Paulson Residence (18558 Langly Ave N) - Revised Rain Garden Location - Drainage Overview Map Good Morning Tom, Thanks for meeting out on site on Tuesday and discussing some of the issues we are facing with the proposed Paulson Residence. We have developed a revised rain garden location/concept and wanted to pass it along for your reference and comment. Attached is a revised Certificate of Survey, Drainage Overview Map and the stormwater worksheet for the proposed rain garden. We added some text explanation to the stormwater worksheet describing our site constraints. We also visually highlighted the septic/well setbacks and elevation constraints on the Drainage Overview Map as discussed on Tuesday. Just wanted to pass these along for a quick review if you have time to make sure we are tracking things moving forward. Please don't hesitate to reach out with any questions or comments on the attached. Thanks! 'Treatment Volume Credit Multiplier BMP (CF/SF unless otherwise noted) Primary Design Assumptions' I lvdrolo sic Soil Grou IISG A B C E D Shallow surface storage (3 -inches) Amended Soils with 0.4 • Compost -amended soil depth (6 -inches) Depressional Storage • Bulk density testing required unless Distri observes soil amendment process Tom Langer Riparian Permit Specialist I Carnelian Marine St. Croix Watershed District 11660 Myeron Rd North I Stillwater, MN 55082 Phone: Q 651 275-74521 Cell: 507.276.8056 a www.croscwd.org From: Frank Brodeen <Frank.Brodeen@widseth.com> Sent: Thursday, September 29, 2022 10:25 AM To: Tom Langer <tom.langer@croscwd.ors> Cc: Richard Paulsen <richard@cedarwoodmn.com>; Shawn Kupcho <Shawn.Kupcho@widseth.com> Subject: 2020-11411—Paulson Residence (18558 Langly Ave N) - Revised Rain Garden Location - Drainage Overview Map Good Morning Tom, Thanks for meeting out on site on Tuesday and discussing some of the issues we are facing with the proposed Paulson Residence. We have developed a revised rain garden location/concept and wanted to pass it along for your reference and comment. Attached is a revised Certificate of Survey, Drainage Overview Map and the stormwater worksheet for the proposed rain garden. We added some text explanation to the stormwater worksheet describing our site constraints. We also visually highlighted the septic/well setbacks and elevation constraints on the Drainage Overview Map as discussed on Tuesday. Just wanted to pass these along for a quick review if you have time to make sure we are tracking things moving forward. Please don't hesitate to reach out with any questions or comments on the attached. Thanks! Frank Brodeen Civil Engineer 651-358-2345 5368 266th Street PO Box 730 Wyoming, MN 55092 W i DSETH Widseth.com 50 Best Places to Work (Prairie Business Magazine, 2022)