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HomeMy WebLinkAbout018 Groundwater Response Memomemo Page 1 TO: Simon Lindley FROM: Celine Saucier DATE: 7/14/2023 JOB NO.: COB 22118 MMI 4192.025 RE: Boulder Creek Apartments Ph 2 SP CC: Urgent For Review Please Comment Please Reply For Your Use Phase 2 of Boulder Creek has 2 storm water facilities: - Retention Pond #3: Proposed for the west side of the site. - Retention Pond #2: Existing pond at the north east corner of the site. This pond was originally designed, approved and constructed as a part of the Boulder Creek Subdivision and at that time was known as Retention Pond #7. See Stormwater Management Design Report Boulder Creek Subdivision by C&H, June 2015. Therefore, this memo is to summarize the analysis of the potential groundwater table impacting the function or maintenance of the proposed storm retention facility, Retention Pond #3. As a part of the Northwest Crossing Project to the north Morrison Maierle observed groundwater levels in 8 wells between May 24, 2019 and November 11, 2019. A high groundwater surface was developed from this information that extends to the south of Oak Street. This surface is shown in the attached exhibit. The estimated high groundwater at the pond bottom is 4739.34 with the pond bottom being 4739.75 with a separation of 0.41ft. It is understood that the city recommends a three-foot separation between high groundwater and pond bottom however the pond was designed to be placed as high as possible for this area given the height was limited by the existing grades of Abigail Lane to the west and the access drive to the south. 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS .R =2 7 0 .0 0 'L =8 1 .0 2 'Δ =17 °11 '3 8 "R=27 0.0 0'L=2 7.4 0'Δ =5°4 8'5 4 "8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS 8''SS .R =2 7 0 .0 0 'L =8 1 .0 2 'Δ =17 °11 '3 8 "R=270.00'L=2 7.4 0'Δ =5°4 8'5 4 "EWEWEWEWEWEWEWEWEWEWEWEWEWEWESESESESESESESESESESESESESEWSEWSEWSEWSSDSDSDSDSDSDSD41.7142.0341.1941.4241.3241.1740.9340.8842.2742.0941.30-1 .54% -2 .70%-1.51%-2.03%-1.58 %-1.85%47394740GROUNDWATER 4739.344NOT FOR CONSTRUCTION08/2021GRAPHIC SCALE0(IN FEET)153015301 INCH = 30 FTTHIS SITE HAS BEEN DESIGNED TO BE ACCESSIBLE TOINDIVIDUALS WITH DISABILITIES IN ACCORDANCE WITHTHE AMERICANS WITH DISABILITIES ACT.ABIGAIL LANETCATCH CURBSPILL CURBTRANSITIONCURB (T)TOP BACK OF CURB ELEVATIONTBCEDGE OF GUTTER ELEVATIONEGLEGENDGRADE BREAK LINE (SEE NOTE 3)NOT FOR CONSTRUCTION08/2021NOT FOR CONSTRUCTION08/2021NOT FOR CONSTRUCTION08/2021NOT FOR CONSTRUCTION08/2021NOT FOR CONSTRUCTION08/2021VERIFY SCALE!THESE PRINTS MAY BE REDUCED.LINE BELOW MEASURES ONE INCHON ORIGINAL DRAWING. MODIFY SCALE ACCORDINGLY!2023COPYRIGHT © MORRISON-MAIERLE, INC.,SHEET NUMBERPROJECT NUMBERDRAWING NUMBERDATEDESCRIPTIONNO.BYN:\4192\025 - THE BOULDERS SITE DEVELOPMENT\ACAD\CIVIL\1-WALL_12.DWG PLOTTED BY:CELINE SAUCIER ON Jul/14/2023REVISIONSDRAWN BY:DSGN. BY:APPR. BY:DATE:Q.C. REVIEWDATE:BY:2880 Technology Blvd WestBozeman, MT 59718406.587.0721www.m-m.netengineers surveyors planners scientistsMorrisonMaierleBOULDERS CREEK APARTMENTS PHASE 24192.025MONTANAGROUNDWATER EXHIBIT16EX1 CMSCMSMEE08/2021 2REVISION 2 - DRC COMMENTS2/12/2021CMSBOZEMANNOT FOR CONSTRUCTION08/2021CONCRETE SWALESEE DETAIL 5/C050PROPOSEDRETENTION PONDVOLUME: 634 CFTOP OF POND: 4741.25BOTTOM OF POND: 4739.75HIGH GROUNDWATERSURFACEHIGH GROUNDWATERSURFACE 5/24/2019 6/9/2019 6/17/2019 6/23/2019 7/1/2019 7/10/2019 7/19/2019 7/29/2019 8/6/2019 8/21/2019 9/5/2019 9/18/2019 10/17/2019 11/12/2019 13 4.92 5.00 2.67 4.00 4.25 4.75 5.58 5.67 5.33 2.25 5.00 5.75 7 2.83 2.58 2.00 2.42 3.00 3.08 3.08 3.17 2.42 2.42 3.34 3.24 2.44 14 3.75 4.50 2.83 3.42 3.58 4.17 4.83 3.00 4.00 3.00 4.79 4.71 3.71 3.41 8 4.17 2.58 2.67 2.67 3.00 3.17 3.33 3.33 3.00 2.24 3.44 3.07 2.17 1.97 10 2.50 1.92 2.25 2.17 2.50 2.50 2.42 3.25 1.25 2.83 3.08 2.55 1.75 1.75 1 3.42 3.25 2.08 2.42 3.83 3.58 3.42 2.17 2.67 1.92 3.69 3.51 2.56 2.26 3 2.75 2.75 2.25 1.75 3.33 4.17 4.58 3.67 2.42 2.00 3.82 3.84 2.84 2.24 4 4.00 4.33 2.75 2.92 4.33 4.33 4.33 4.33 3.00 3.42 4.61 4.60 3.90 3.50 *NOTE: NorthWest Crossing Subdivision - Weekly Water Levels (FT) Well DATES Value in each cell is the measurement from the ground level at each monitoring well to the static water level in each well. 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 5/17/2019 5/31/2019 6/14/2019 6/28/2019 7/12/2019 7/26/2019 8/9/2019 8/23/2019 9/6/2019 9/20/2019 10/4/2019 10/18/2019 11/1/2019 11/15/2019Groundwater depth (feet)Date NorthWest Crossing Groundwater Depth Well 1 Well 3 Well 4 Well 7 Well 8 Well 10 Well 13 DYHDYHDYHDYHDYH DYHDYHDYH I SGV I SSSSSSSSGVMWMWMWMWMWMWMWMWS SSSSSSSSSSSSTPTPTPTP TP TP TP TP TP TP TPTPTPTP TWV WV WVWV WV WVWV WVWV WV WVWVWVWV WV WVWVWVWVWVWVWVWV WV WV WV WVWV WV WV WV WV WVWV WV WVWV WV WV WV WVWVWVWV S0°59'41"W 2627.49'S89°30'03"W 2649.87'N0°25'52"E 2625.17'N89°27'46"E 2675.75'MWMWMWMWMWMWMWMWFIGURE NUMBER©PROJECT NO.DRAWN BY:DSGN. BY:APPR. BY:DATE:COPYRIGHT MORRISON-MAIERLE, INC.,2019N:\5659\004 NW Crossing Master Site Plan\ACAD\Exhibits some MSP EX are in 005 Acad Survey Pre App\C 120 Surface Water and WetlandsLocations.dwg Plotted by matt e. ekstrom on Sep/9/2019engineers surveyors planners scientistsMorrisonMaierle1 Engineering PlaceHelena, MT 59602406.442.3050www.m-m.net 5659.004 C120NORTHWEST CROSSING SUBDIVISION BOZEMAN MTSURFACE WATER ANDWETLANDS LOCATIONS MEE MEE MEE 09/20192004001002000SCALE IN FEET50' WETLANDSETBACKDELINEATEDWETLAND BOUNDARY50' WETLANDSETBACKDELINEATEDWETLAND BOUNDARYBAXTER DITCHBAXTER CREEKGROUNDWATERMON. WELL - #1GROUNDWATERMON. WELL - #3GROUNDWATERMON. WELL - #4GROUNDWATERMON. WELL - #14GROUNDWATERMON. WELL - #13GROUNDWATERMON. WELL - #7GROUNDWATERMON. WELL - #8GROUNDWATERMON. WELL - #10