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HomeMy WebLinkAboutRIDGEWOOD HILLS FIFTH FILING - FDP200024 - SUBMITTAL DOCUMENTS - ROUND 2 - WETLANDS DOCUMENTS1 Wetland Monitoring Report, 2020- Ridgewood Hills Project Prepared For: GoodwinKnight 8 605ExplorerD rive,Su ite 250 C oloradoSprings,C O 8 0920 Prepared By: W ildland C onsu ltants,Inc. 1001 JeffersonD rive B erthou d,C O 8 0513 Febru ary2021 1.0 Project Overview The Ridgewood H illsdevelopmentislocated insou thFortC ollins,C olorado.The site isbou nded onthe northbyTriangle D rive and Sou thC ollege A venu e onthe east.The proposed residentialdevelopmentis located onatotalofapproximately34+-acres.The developmentinclu dessingle familyresidential,mu lti- familyresidentialand commercialu ses. The existingsite inclu deswetlands,the N orthL ou denD itch,and seeded grasslands.A fterconstru ctionapproximately10.8 5acres+-willbe designated asopenspace. P roposed openspace areasinclu de existingwetlands,wetland mitigationareas,portionsofthe N orth L ou denD itch,and otheropenareas.O penspace areasare designed tomitigate forlostwetlands,ditchand N atu ralH abitatB u fferzones. W ildland C onsu ltants,Inc.(W C I)completed aformalwetland delineationand W etland D elineationReport forthe projectin2019(W C I2019). The W etland D elineationReportwassenttothe A rmyC orpsof Engineers(A C O E)forreview.W C Irequ ested anapproved Ju risdictionalD eterminationforwetlandson the site from the A C O E.The A C O E determined thatallofthe wetlandsonthe site are non-ju risdictional (A C O E 2019). W etland mitigationisbeingproposed onthe site tomeetC ityofFortC ollinsrequ irements notA C O E requ irements. C u rrentlyprojectconstru ctionisproposed toremove 0.49 acresofwetlandsonthe site.These wetlands are mainlyassociated withthe N orthL ou denD itch.The C ityofFortC ollinswillrequ ire mitigationfor these lostwetlands.M itigationwillbe completed ona2:1 basis.Thu swetland mitigation/creationofnew wetlandsisproposed foratleast1 acre (notinclu dingwetland created indetentionponds). 2 2.0 Monitoring Procedures Preconstruction Monitoring P reconstru ctionmonitoringwascompleted tocharacterize existingwetland vegetation(atthe end ofthe growingseason),soils(wetland characteristics)and existingwetland hydrology(throu ghthe growing seasonand wintermonths)inand arou nd W etland 4(inclu dingproposed wetland mitigationareasarou nd W etland 4). W C Iinstalled 9 shallow grou nd waterwetland monitoringwells(M W )inand adjacenttoW etland 4(M W 1-9)inlate M ay/earlyJu ne 2020.Twoexistingmonitoringwells(M W 10-11)were alsolocated and were inclu ded inthe monitoringprogram.L ocationsofmonitoringpointsare shownonFigu re 1.A staffgau ge (SG1)wasplaced inthe N orthL ou denD itchtothe westofW etland 4. The goalofthe grou ndwater monitoringwillbe todetermine the depthofgrou nd waterwithinand adjacenttoW etland 4.B yplacing the staffgau ge grou nd waterdepthcanbe related tothe seasonalflowsofthe N orthL ou denD itch. N ote:W C Idid notdrillM W 10 or11.These wellsare bothover20 feetdeep,thu sgrou ndwaterlevels maybe influ enced byadeeperwatertable thatoccu rsu nderneaththe imperviou sclaylayeronthe site. W C Istopped drillingmonitoringwellswhenwe firsthitgrou ndwater,thu sou rwellsranged indepthfrom 2.8 to8 .3feet. EachM W wasmonitored twice monthlydu ringthe growingseason(Ju ne-September)and once monthly ou tside the growingseason(O ctober-Janu ary)in2021.N ote:monitoringwellswere notinstalled intime tocomplete aM ay2020 monitoring. 3 Figu re 1. M onitoringW ell(M W )L ocationsinand adjacenttoW etland 4(SG=staffgau ge inditch). 3.0 Monitoring Results Vegetation- Table 1 su mmarizesthe vegetationcompositionateachmonitoringwell.W ithinthe delineated wetland areathe monitoringwellswere dominated bywetland vegetation(vegetationwitharankofFacu ltative, Facu ltative W et,orO bligate).O u tside the delineated wetland vegetationwasdominated byu pland ornon- wetland plantspecies(Facu ltative Upland,Upland orN on-Indicatorspecies). 4 Table 1.Vegetationaerialcover(percent)in2 meterradiu sarou nd monitorwellcasings(fall2020). Scientific Name Common Name (Wetland Indicator Status) Monitor Well No. 1 2 3*4 5 6*7*8*9 10 11* Asclepias speciosa showymilkweed (Fac) T 15 Agropyron cristatum crested wheatgrass(Upl) Bromus inermis smoothbrome (Upl) T 50 20 Bromus tectorum C heatgrass(N I) 20 10 Cirsium arvense C anadianthistle (N I) 20 5 50 20 10 5 2 30 Distichlis spicata coastalsaltgrass(FacW ) 20 10 Epilobium cilatum fringed willowherb(FacW ) T Epilobium hirsutum codlins-and-cream (FacW ) T Juncus balticus B altic ru sh(O bl) 20 20 20 20 10 Lactuca serriola pricklylettu ce (FacW ) 5 5 Lepidium latifolium broad-leafpepperwort(FacW ) 5 T T Melilotus officinalis yellow sweetclover(FacU) 25 T Muhlenbergia asperifolia alkalimu hley(FacW ) 50 Phalaris arundinacea reed canarygrass(FacW ) 20 Poa pratensis Kentu ckyblu egrass(FacU) 20 Rumex Crispus cu rlydock(FacW ) T T Schedonorus arundinaceus tallfalse rye grass(FacU) 20 30 20 7 0 Schoenoplectus pungens three-squ are (O bl) 7 0 20 7 0 30 Sporobolus airoides alkalisacaton(Fac) T Thinopyrum ponticum tallwheatgrass(Upl) T 20 Unknownforb T T B are grou nd 10 3 0 0 0 0 0 0 0 30 20 L itter 2 25 25 40 10 5 5 5 23 20 10 * =welllocated inexitingwetland,T=lessthan1 percentaerialcover Fac=Facu ltative species(equ allylikelytooccu rinwetlandsand non-wetlands) FacW =Facu ltative W etspecies(u su allyoccu rsinwetlandsbu toccasionallyfou nd innon-wetlands) O bl=O bligate wetland species(almostalwaysoccu rsinwetlands) FacU=Facu ltative Upland species(u su allyoccu rsinnon-wetlands,bu toccasionallyfou nd inwetlands) Upl=Upland species(almostalwaysoccu rsinnon-wetlands) N I=non-indicatorspecies 5 Soils- A tthe monitoringwelllocationwithinthe existingwetland (M W 3,6,7 ,8 ,11)wetland soilsare present. W etland soilcharacteristicsofmottling(redoxymorphic indicators),low chromacolorsand satu ration withinthe u pper12-inchesare present.A llwetland soilsare clayloam intextu re. O u tside ofthe existingwetland (M W 1,2,4,5,9,10)there are nowetland soilspresent(nowetland characteristicsinthe top12-inchesofsoil).Soilsou tside the existingwetland are classified asu pland soils (nowetland soilcharacteristicsare present).A llu pland soilsare clayloam intextu re. W hile drillingthe monitoringwellssoillayerswere noted.W ithinW etland 4there isaclaylayerat1.5-2 feet.Thisclaylayerextendsbeyond the bou ndariesW etland 4,monitoringwellsdrilled ou tside W etland 4 alsoshow aclaylayerat1-3feetindepth. Hydrology- Table 2 su mmarizesthe resu ltsofthe grou nd watermonitoringfrom Ju ne throu ghD ecember2020.W ithin W etland 4(M W 3,6,7 ,8 ,11)grou ndwaterwasatthe highestelevationinJu ne,the lowestelevationinlate A u gu stand stabilized inN ovemberand D ecember.Figu re 2 showsthe highestgrou ndwaterelevationin 2020. M onitoringwellswere installed inearlyJu ne afterthe firstditchflowsoccu rred (likelysometime in M ay)thu sthe impactofthe firstditchflowsongrou ndwaterlevelsisnotcompletelyknown.H owever, based onthe factthatthe highestgrou ndwaterlevelswere observed inearlyJu ne itislikelythatthe first ditchflows(flowsdu ringthe firstweekortwoofoperation)raised the stabilized wintergrou nd water levelstothe highestlevelofthe year. Grou ndwaterlevelsinthe wetland areawere atthe lowestinlate A u gu st(whenditchflowswere atthe highest).Thisislikelydu e toevapotranspirationresu ltingfrom peak plantgrowth.The wetland areasu pportsalarge biomassofplantgrowth. O u tside ofexistingW etland 4(M W 1,2,4,5,9,10)grou ndwaterwasatthe highestelevationinearlyJu ne, the lowestelevationinlate A u gu stand stabilized inN ovemberand D ecember.The highestgrou ndwater elevationisshownofFigu re 2 (feettogrou ndwater).ForM W ’sou tside ofW etland 4the depthto grou ndwaterranged from 1.8 feet(M W 9)to7 .6feet(M W 10)inearlyJu ne. W etland 4ishigherinelevationthanthe majorityofthe adjacentnon-wetland areaswithinthe smallbasin arou nd W etland 4.W etland 4sitshigheronthe landscape thanadjacentnon-wetland areas. Earlyditchflows,likelyresu ltinaflu shofwaterintoW etland 4.The shallow claylayer(1.5-2 feetdown) mayresu ltinaperched orhigherwatertable overthe imperviou sclaylayer.W etland 4isatthe head ofa natu raldrainage thatflowstoward FossilC reek.Ju stwest(approximately28 0 feet)ofthe N orthL ou den D itchand W etland 4isanotherlarge wetland (approximately1.3acresinsize)thatisnow partofa detentionpond.Thiswetland ishigherinelevationthanW etland 4(approximately10 feethigher)and isat the verytopofthe historic drainage thatinclu desW etland 4. H ydrologyinW etland 4and the adjacentnon wetland areasislikelyinflu enced byflowsinthe N orthL ou denD itch,and natu ralgrou ndwatermovement throu ghthe historic drainage (likelyfrom the large wetland tothe west). Table 2. Monitoring Well Summary Data: June 2020-December 2020 Easting UTM Northing UTM Well Depth (feet) Stick- Up (ft.) MW No. Ground Elev.*** 6/05/20 Depth to GW (ft.) 6/10/20 Depth to GW (ft.) 6/24/20 Depth to GW (ft.) 7/07/20 Depth to GW (ft.) 7/21/20 Depth to GW (ft.) 8/06/20 Depth to GW (ft.) 8/21/20 Depth to GW (ft.) 9/05/20 Depth to GW (ft.) 9/15/20 Depth to GW (ft.) 10/1/20 Depth to GW (ft.) 11/5/20 Depth to GW (ft.) 12/4/20 Depth to GW (ft.) 493132 4481164 6.3 1 1 5060 4.08 3.71 3.98 4.57 5.33 5.14 5.70 5.05 4.05 5.13 5.52 5.52 493171 4481148 8.3 1 2 5055.6 4.76 4.83 5.14 5.41 6.01 6.22 6.49 6.28 5.52 5.71 6.10 6.05 493118 4481129 6 1 3*5058.1 2.02 1.49 2.10 2.56 3.25 3.08 3.45 2.69 1.96 2.64 2.46 2.52 493157 4481123 6 1 4 5055.1 3.11 2.92 3.69 4.15 4.87 5.14 5.56 5.61 4.68 4.96 4.58 4.19 493198 4481116 6.1 1 5 5050 3.31 3.29 4.11 4.71 5.36 5.67 5.85 5.93 5.31 5.27 4.79 4.41 493068 4481097 3 1 6*5058.55 1.09 0.19 0.76 1.29 1.92 1.86 2.10 1.87 0.60 1.09 0.55 0.85 493104 4481094 2.7 1 7*5055.8 0.77 0.15 1.43 1.72 1.52 1.43 1.70 1.09 0.33 0.87 0.65 0.88 493138 4481092 2.8 1 8*5053.3 1.90 0.13 0.68 2.01 1.94 2.15 2.34 1.74 0.58 1.00 0.46 0.43 493178 4481090 6 1 9 5049.8 2.35 1.81 2.79 2.95 3.44 3.72 4.10 4.02 3.29 3.44 2.98 2.44 493198 4481173 22.4 1.6 10 5057.4 7.39 7.61 7.33 7.37 7.39 7.25 7.17 6.94 6.44 7.56 8.59 8.81 493129 4481100 23.55 1.45 11*5055.1 0.14 -0.06 0.28 0.74 1.30 1.23 1.58 0.86 0.27 0.66 0.41 0.45 Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) Water Depth in Ditch (ft.) 493063 4481118 Tee-post 3.2 SG- 1** 5061.1 0.5 0.5 0.3 0.49 0.26 0.99 1.13 1.15 0.4 0.16 dry dry *MW is located within existing Wetland Number 4. ** SG-1=Staff Gauge in North Louden Ditch ***Ground Elevation is approximate (needs to be surveyed) Figure 2. Highest groundwater elevation (feet to groundwater)(June 10,2020)during the 2020 monitoring. 6 4.0 Literature Cited A rmyC orpsofEngineers,2019.A pproved Ju risdictionalD etermination,Triangle P roject. W ildland C onsu ltants,Inc.2019.W etland D elineationReportTriangle P roject.