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HomeMy WebLinkAbout2021 10-12 CC WORKSHOP PACKETCity of.Gem Lake, Minnesota - City Council Workshop, October 12, 2021 Cali to Order of City Council Meeting By May orArfig-Swomley at 7:_p:m. Call of Roll Others In Attendance: Sign=up.Sheet Agenda New Business City Council Workshop Agenda. for this Meeting (Accept Agenda) • Introduction • Scheuneman Road Storm Water Report Presentation=Emily Jennings, SHE • Question. and Answer Session Future Council Meetings Next City Council Meeting, Tuesday October 19, 2021 Adjournment The meeting :adjourned at 11/2/2021 C i of Gem lake North Scheuneman Road Surface Water Management Plan July 20:. M21 A SE11 Introduction • Spring 2019 — Late:winter snow, rain and an expedited melt Inundation and Flooding in the Scheuneman Road Area • Summer 2020 - Culvert lnspedons Structural, SedlmentaWn, £roson and Submerged Conditions —Generally speaking, culverts were in good shape — Not evaluated for hydraulics • Hydraulics evaluation by preparing SWMP Study Area • North Scheuneman Road between Highway 61 to Otter Lake Road with the primary areas of interest located at: Cross.culvert and ditch system discharging to 39g9 Scheuneman Road ("Culvert -Area") - Low areas at 3M.and 3924.Scheuneman Road ("South Area") - Low area 4076 Scheuneman Road • Receiving Waters - Golf Course Pond, Gem Lake, Wetlands, Hillary Farm Lane Pond - Other Low Areas 1 11/2/202I Approach • XPSVVMM 2D - Numerically and graphically estimate where and to what depth inundationnay occur during a given design storm event - Survey data, LiDAR data, Web Soil Survey • Design Storm Events - Worst flooding observed during Spring — 2-year, 24-hourpreclpitatlan eventon frozen ground — 10-year, 24-hour precipitation event on frozen grs7und - "Typical Major Event'. 100 year, 24-hour Precipitation event on non -Frozen ground (.9%chance of occuning.in any given year) .5f Ha:aws a e•o�r vraw e. rr e:ir Existing Conditions • Peak Inundation and Depth (>0,2 feet) • Verified drainage issues:. observed: and: as reported Culvert Area - Ineffective Flow • South Area -.Lack of Conveyance • 4076 Scheunerrtan Road - Lack of Conveyance 2 11/2/zozl 3 11/2/2021 I I 11/2/2021 Flood Risk • For the purpose of the SWIUfP, flood risk is defined as properties that are wiit.hid 1 foot of the peak water surface elevations • Study area is not in a mapped floodpla'in • Recommended that properties that are at risk for flooding consider purchasing flood insurance SEN Existing Conditions J' v+eN.ra wb.w ro��wvl.rwlaenm ru 4n. wnrl 1 tunert+V�a +wnu 93e 1e Y)1,J1 a, l.v>i]131. 2 Lmrirt Juw a7o1 91831 877,78 A}f,91 BSe:e � .a1721 ] CVnan Mal 7i70 916 :'e G11.•6 � i3A3B i' Qd1'•1♦MH J:m 8.15]3 WAS a1L67 9]e]B 1 Sv+R� 4ea ]MA B56 67 BL5 _B :11.!} � G55 i+ .}. SauNAmi BSBOt Pee.M emu Su+N Nv ]c1G P1Gd! a5B.0/ ieB 17 � 6i9.10 � JBIi iL19t Culvert Area • Provide Effective Flow • Two Scenarios — (.1) U.psize.culvert+and backyard swale.grading — (2) Upsize culvert and side yardlROW swale grmding �y i 5 xs/z/1021 - :Culvert t-:ti .: k ; —.4t :# �.• •• _.�� }:pltMfwt llNpM1,1 :�'::. i4i4YYWi. siipct ' � • If w'.,ilenlwsgt + Culvert r' k'Area f21 J• ° •>Mt v ►WtY�Ml'�'�: Mii lnMili7*: South Area • Provide Discharge Location • Three Scenarios (t).Storm sewer _ System to natural low area (2) Storm sewe: system Id Hillary Farm Lane Pond = (3):Storm sewer system. to Gem Lake sfn �11 0 •.';.k�,�; ���ji�'t • • • r Pam._ .-�_ yy.�yt • � y 11/2/2021 Recommendations CulvertArea. Scenario 2 -�-•- - Red::,,e F'ped Risk %w SE" Recommendations 1 • South Area 5ceriario 2 or 3 2: To Hillary Farm Lane Pond 3. Ta Gem Lake Scenario 2 requires additional investigation — Scenario 3 requires agency approvals Similar benefit to flood risk.and inundation durabon Similar impacts; slightly more to private property in Scenario 2 21, SEH ,..... _. Questions? Emily Jennings. (651).302-7669 e ienh ings0i), seh inc.co m SEH lWf.rga0••i iV�M4 /.'sNu�• 9 CITY OF GEM LAKE Heritage Hall 420U Otter Lake Road I Gem Take, MN 55110. 651447-2790/921651-747-2.795 (fax) - E-mail cit iyQumlakemn.ore Gem Lake Workshop October 12; 2021 Sign in Sheet