The URL can be used to link to this page

Home My WebLink AboutGrading Plans - 08/24/2022\y��\1 / � � �J �") - G � � �� -_ � l , � - - - - - _ ;�, ,�,,,. -,//' � > , � %��T, J . � i�� a��0 � August 22, 2022 Water Utilities Engineering City of Fort Collins 700 Wood Street Fort Collins, Colorado 80522 RE: 512 Peterson Street Drainage Memo To Whom it May Concern: KEEFE CIVIL, INC 3125 Crockett Street Fort Collins, Colorado 80526 (970) 215-6808 meg@keefecivil.com Keefe Civil Project Number: 2022-021 Grading/Stormwater Plan Accepted (Building Permit Released) Accepted by: Dan Mogen Date: 08/24/2022 The purpose of this letter is to describe the proposed site improvements and potential drainage impacts at 512 Peterson Street (Exhibit A). The 0.22-acre project site is a developed single-family residential lot with established landscaping located o�z the east side of Peterson Street between East Mulberry Street and East Myrtle Street in Fort Collins, Colorado. The site is located within the Old Town drainage basin. Current conditions at the site include a single-story house, detached garage, concrete patio, concrete walkways, established trees, and a concrete and gravel driveway. The lot is bound by existing single-family residential properties on the north and south lot lines, Peterson Street right-of-way to the west, and a dirt alley way to the east. Per the NRCS Soil Survey of Larinler County (Exhibit B), the site entirely consists of Fort Collins loam and is classified as being within hydrologic soil group C. These soils are anticipated to have a slow infiltration rate when thoroughly wet and a slow rate of water transmission. Per the flood insurance rate map, the lot is located within Zone X. Zone X is defined as an area of minimal flood hazard and does not have a base flood elevation associated with it. Also, the site is outside of all City of Fort Collins mapped floodplains. (E�ibit C) Historically, site stormwater for the front portion of the site has drained with gentle slopes from the east to west into Peterson Street right-of-way (historic basin A). The rear portion of the lot, when not infiltrated into established landscaping, has drained with gentle slopes towards the alley (lustoric basin B). Based on field inspections, the alley appears to drain south towards Myrtle Sh eet right-of-way. Historic and developed drainage basins are shown in Exhibit D. No improvements are proposed in drainage basin A and the divide between the basins will not change; therefore, historic and developed drainage basins are the same size and no runoff increases are proposed in basin A. The proposed site iinproveinents in drainage basin B include a single- story garage with gravel driveway access off the alley. A proposed concrete pathway shall be extended from the existing garage to the new garage entrance on the west side. Both garage roof a -L `r� -a� -� -L� —�+ -b .3 -3 -L - � -i� -C� -L 'Q � V D O � G d � G O G _ � .� O T� Q' a a e a e a a a d a" 6 e a d e a e a e a� a a a a a c a a v a v a a v a� v c v a a a a a v a a v a a a c , °b �� °o eD Qd °�, °b °o'�� °b ao ed eb �o ea Qp �o �d °d �o �'o �4 �Q �d ab � QAAAAG��A.caAAA�G�AA�AAAAG�s�AA` 512 Peterson Street Drainage Memo Keefe Civil Project No.: 2022-021 Page 2 of 5 August 22, 2022 drains are proposed to drain west, into 55-gallon rain barrels (two total). Where possible, impervious areas and downspouts shall be routed into pervious areas with landscaping to allow for project stormwater infiltration and increased water quality with site runof£ Since the lot's total adjusted impervious area increase is below 5,000 square feet (s�, water quantity detention requirements ai-e not required for this development. Adjusted Adjusted Overall Site Hardscape or Hard Historic Site Historic Developed Developed Surface Area (s� Area (st� Site Area (st� Area (st� Concrete 1,135 1,135 1,215 1,215 Rooftop (90%) 1,985 1,787 2,809 2,528 Gravel (40%) 860 3�4 1,000 400 Total Impervious Area 3,980 3,266 5,024 4,143 Adjusted Site Imperviousness 878 The total site imperviousness is 44%, which is less than the 50% allowed within the Old Town drainage basin master plan (ICON Engineering 2017). The composite runoff coefficient and drainage basin runoff calculations for the historic and developed site are included in the enclosed tables (Exhibit E). Using the Fort Collins Stormwater Criteria Manual (2018), the proposed stoimwater runoff from the site wi11 increase with development as indicated in the suinmary table below. 2-year 10-year 100-year Basin A Historic & Developed Runoff 0.02 cfs 0.04 cfs 0.09 cfs Basin B Historic Runoff 0.11 cfs 0.19 cfs 0.52 cfs Basin B Developed Runoff 0.16 cfs 0.28 cfs 0.77 cfs The drainage design proposed with this project will limit potential damage associated with its proposed stormwater runof£ The site will detain pervious areas converted to impervious areas to release close to the existing 2-year rate. The 2-year peak runoff rate for drainage basin B is 0.72 cfs/acre. This release rate was utilized in the FAA procedure detention storage coinputations (Exhibit E). From these calculations, the site produces an excess runoff detention volume of 45 cubic feet (334 gallons) of required storage capacity over the existing site due to the proposed increase m site �mperviousness. CDS Engineering Corporation (2022) completed field investigations at the site, which included a boring drilled to 12 ft below ground surface. Groundwater was not observed during investigations and subsurface conditions were observed to consist of clay soils. Since use of dry wells for stormwater management is only feasible where subsoil is suf�ciently permeable, infiltration is not a viable option with this site. Beginning in 2016, Coloradoans have been allowed a maximum of two rain barrels with a combined siorage of ll 0 gallons or less. With the use of two rain barrels on the new garage downspouts, the site will detain approximately one-third of the required runoff. Any potential rain barrel overflow shall drain into proposed grass swales directed towards landscaping improvements and lot lines, which naturally drain towards the alley. _ _ —�.. �. . �_ �: '� �G� v+3 v�. v� v3 v�• vp Q� Q+3 �D v3 Qp �� vp v� v3 pp v�• Q►3 v� QC vp vC' vp Qp , a a e a e a a a a a a e a a e a e e e a a a a a a c a a v a v a a v a a v v v a a a a a a a a v a a a c � °v °� °o °� °d °d °v � °c °d °� °� °d °o °a °a °v °d °c °� °Q °d °v °d °c � QAA4AG��As�A�AG�AAA�AAAAG3qAA� 512 Peterson Street Drainage Memo Keefe Civil Project No.: 2022-021 Page 3 of 5 August 22, 2022 Based on visual inspections of the alley, it is my professional opinion proposed improvements presented in this drainage memo will not negatively impact downstream private properties adjacent to the alley before draining into East Myrtle Street right-of-way to the south. Based on the enclosed design, it is iny professional opinion the additional runoff generated by these site improvements will not cause adverse impacts to downstream private properties. I hereby attest that this letter for the final drainage design for 512 Peterson Street was prepared by me or under my direct supervision, in accordance with the provisions of the Fort Collins Stormwater Criteria ManuaL I understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by others. Thank you for the opportunity to submit this drainage memo. Please do not hesitate to reach out to me if you have any questions or comments regarding the above iteins. Best regards, �PDO LICF �O ........... 2s VO� ; PN L. � •.� FO C� :g�' 08/22/22 m: ; 39�,7,8 ,ey : ,`"�"'�f" ee , , � oa�9'=zou��P��,e3,� �� , o .;�� Megan L. Keefe, PE / Manager G~Fss/pNALE��\�� Keefe Civil, Inc. Enclosures Cc: Jesse Applegate, Mighty Hand Construction RefeYences CDS Engineering Corparation. 2022. Geotechnical Exploration for 512 Peterson Street, City of Fort Collins, Larimer County, Colorado for Mighty Hand Construction. Project number 22-1351. February 22, 2022. Fort Colluls Stonnwater Criteria Manual. 2018. ICON Engineering. 2017. Old Town Drainage Basin EPA SWMM Conversion and Hydrologic Update. ��p. v� v� v� v� v�. vQ �p Q� _�� v� QQ q�. v�. v� _v� pp v� �3 v�. �� v_ � v4 vp.�� , a a e a e a a a a a a e a a e a e e e a a a a a a c a a v a v a a v a a v v v a a a a a a a a v a a a c � °v °� °o °� °d °d °v � °c °d °� °� °d °o °a °a °v °d °c °� °Q °d °v °d °c � QAA4AG��As�A�AG�AAA�AAAAG3qAA� � � � �� i�I�f�IT� �' �. ��"'��"`..-:��,- ., - - - � ; � ,:�w�,d �,� `,'- .�� - �� -�a,�; :�Mt� `"�� , ,�,� __ ` �- _--- - ` >.�,= _� -� ,..�,x,:� �� I �.... =-,. °��,�.. Alley adjacent to project site: � � ��\ � ��, ,x. C;+1 Jb. �. �.t_..� � . . �� r�.}� `1 . •k�u'• . _ _ . �ti ,l �� I^.' .'.��_ �� ; � `r! , — � � _ — ��4�,:��;-�-.��•��;�p � p�,=pe ��p�p�p-�=p-=�p-u-Q r,.4�:-p_._,�:�a_..��D-�-�-,�.�p-.�-p-...d p-�p� Ti � V D 0 O G Q Q G 0 Q G � Q G p � Q 0 Q � O G7 Q' a a e a e a a a a a a e a a e a e e e a a a a a a c a a v a v a a v a a v v v a a a a a a a a v a a a c � °v °� °o °� °d °d °v � °c °d °� °� °d °o °a °a °v °d °c °� °Q °d °v °d °c � QAA4AG��As�A�AG�AAA�AAAAG3qAA� ; �;n .�,�.._ . _ �, - � �'` � . �,_�� — � _ Front of house from Peterson Street: �-- Adjacent alley way looking north from Myrtle Street right-of-way: �� . :� `'�` '.. �.:�- ��, . �:. _ _�,�.=�:.� P'M` � �'� � - � ��" , ' . ' ._ 4 - � il � �.?I . ..: � . �. � �.r .n � ' . . . . - _X3 �-�-p�-��-�-z-� �p__:_p =-p�-ae-�-.rp�.4 �..�-p.._.p-�.-�--�--Q �,.�-�p-�-.�•�:,�-�-D��..4 �..Q_�.:p d_p_ Ti � V D 0 O G Q Q G 0 Q G � Q G p � Q 0 Q � O G7 Q' a a e a e a a a a a a e a a e a e e e a a a a a a c a a v a v a a v a a v v v a a a a a a a a v a a a c � °v °� °o °� °d °d °v � °c °d °� °� °d °o °a °a °v °d °c °� °Q °d °v °d °c � QAA4AG��As�A�AG�AAA�AAAAG3qAA� N � f �1 LEGEND: � �� '" �� L � w � � � � � � � r_ _ � �� , � � � T 1 ! 9 �_ { � � �� rt �� 4 � � �� . � — T � � R � � EXIST/NG � { CONCRETE DRl I/EW,4 Y � �: s r_ � . ' r r i �-� �� . . t ; y � — � L� = � �N �� o � 00 0 .�.rr o _ _�r 4 `#� o � t� ` � �� f � _ ,� R � '` ■ � � . �,* � � � f - � � � � � . ,,� � � � � ' � � � �*� � � � � � � � � � . •� � ` � �' � M � � �g�� . X gg�.9� X �� 2� � (� %) 0 0 a . pv �� DS/RB � � � � � � � � .�► A 0.042 AC F F- E E - OHE OHE V V X PROPOSED SPOT ELEVATION EXISTING SPOT ELEVATION PROPOSED SLOPE EXISTING SLOPE PROPOSED CONCRETE PROPOSED GRAVEL PROPOSED FLOWLINE PROPOSED DOWNSPOUT WITH RAINBARREL AND OVERFLOW DIRECTION DRAINAGE BASIN LIMITS � � CONCENTRATED DRAINAGE FLOW DIRECTION OVERLAND DRAINAGE FLOW DIRECTION DRAINAGE BASIN ID DRAINAGE BASIN AREA (ACRES) EXISTING UG ELECTRICAL SERVICE PROPOSED UG ELECTRICAL SERVICE EXISTING OVERHEAD ELECTRIC LINE EXISTING FENCE � � � �� ,� r ;� , r r � � �� M,• R � � i � � . �i � r r � � _ � � � '� � � �h � 1 � � :� , L� � u ' `�� r� � � � �T � � � w � �. � r ` '� * `�� 1 '� • s i rt� � + � i= r � � q ` _ _ � � � � . 4986.9) (4986.1) d �, � � � , 1 �� * � ` 'S89'51'48"E � ;• ' 4986 8 - } �2%� � r M � � 190 :00' _ _ — — — � Tx � : � � . i � 1 1 • � . � ' � _ �1IM �a� � — �l DS/ B � �`;•, I �:;' � ; �f ' �. r � — � .S I � � n Q � . � � �� I � ��'.� 4987.3 \,4.986J' � I I EXISTING � F� - - , F� `�� EXISTING I GRA l/EL I GARAGE TO 2% \N, �� PROPOSED GRAVEL DRIVEWAY ORl l/EWA Y ' I I REMAIN I — 4987.0 Sg FG 87.3 �,, -. 6,� �� _ __ A � .,� . I I�I _ �l I� — — — — k - I FL \ �g$� FS 4987.19 � ) , � GFF , � 0.065 s � � �s —� ps ,� 4987.44 ° ° D � � _ � _ _ _ _ _ T� � _ _ �J —�' � 4 , 4 4 a . FS COVERED ** ALL ROOF DOWNSPOUTS ti �; �� AC � — — af — � --�--� —\=---�----�, ` �.. Qi ' ` a '' ' .P2% ,�a SHALTHE WESTC**D TO �= Z �� s—�----- � � � � �`� - ,,. , � o �� ' < ' i � � � \ � / � 4986.9 "I°�° m � W � j / � (� � � Z F� \ FS87.44 / ,4987.1 4986.1 09 .. 4� J = ' . / �� / �� ;,�� /FG FG o N Q � v� � EXISTING / �—�-- _a----.�� o� ��' �o �9 / � , DS/RB� � �ggi / � o --o o � x � - HOUSE TO ' I a a 4 � � o �� o �� o REMAIN � � a Q �� n � � o �� /�� N ir� �, � � � � /o� � J GRADEBREAK� � � * ' , EXISTING CONCRETE � � y Z 4986.9' 4gg6.4 , PA T10� TO REMAIIV J , n� � �,�/ ��Q I�� M ' ' ° a / �' I 0.153 �� r, � -�� ", � I � ,�/ /I /�C / 4986.7 � ;�o I V � � �� `�' �-------� / � � / I / , � �� ,� • � ` I , �. � '� � - 190.00' _ � � ti - {�i) �', � ' • � N89"51'48"W * . �, � • ' �• k , , 1 �� "��j � � (4986.6)� � , -� (4986.0) �� i 2 ' �.� , PROTECT IN PLACE EXISTING TREE � . � _1�� N ' . � � � � �• � �� ~. �� * EXI DENCE � , � �� . � � � '�''� r � � � �r � ♦ �l �4 �� '� �R � i ^'� �1 4 � �"�� . • � K � � � � , � Y � =� ' � '� P� � � � . 1 '� r . � • � � � '+ � . N! � ��1 � f � � ! fti � _� � �, . � � �. �� ` � � � ' � � _ � � � � _ + ��. � �— �' - �� . 1 1 1 1 � �� ABBREVIATION LEGEND: AC ACRES BOW BOTTOM OF WALL DS DOWNSPOUT DWG DRAWING EG EXISTING GROUND EOG EDGE OF GRAVEL EX EXISTING FF FINISHED FLOOR FG FINISHED GRADE FL FLOWLINE FS FINISHED SURFACE (CONCRETE) GB GRADE BREAK GFF GARAGE FINISHED FLOOR HP HIGH POINT LP LOW POINT ROW RIGHT—OF—WAY TOW TOP OF WALL WW WINDOW WELL GRADING NOTES: 1. TOP OF FOUNDATION MUST BE AT LEAST 6" ABOVE THE HIGHEST GRADE SURROUNDING ALL BUILDINGS. 2. THERE MUST BE A MINIMUM GRADE OF 5� AWAY FROM THE BUILDINGS WITHIN THE FIRST 5 TO 10 FEET ADJACENT TO THE RESIDENCE. 3. SLOPES MUST NOT TO BE STEEPER THAN 33� (3:1). 4. ALL PROPERTY PINS, INTERSECTION MONUMENTS, AND SECTION CORNERS DISTURBED DURING CONSTRUCTION MUST BE REFERENCED AND REPLACED UNDER THE SUPERVISION OF A LICENSED SURVEYOR. 5. ALL CONTROL SHOWN SHALL BE VERIFIED BY THE CONTRACTOR BEFORE ANY CONSTRUCTION OR OTHER IMPROVEMENTS. Adjusted Historic Site Area Historic Area Adjusted Developed Overall Site Hardscape or Hard Surface (sf) (sf) Developed Site Area (sf) Area (sf) Concrete 1,135 1,135 1,215 1,215 Rooftop (90%) 1,985 1,787 2,809 2,528 Gravel (40%) 860 344 1,000 400 Total Impervious Area 3,980 3,266 5,024 4,143 Adjusted Site Imperviousness 878 � , � Know what's belOW. C1II before you dig. .� � � -� r m N O � N N O N O Z m � � N N O N � O N Z n 0 o ~ ¢ 0 ��o�P D O L I�F�s ��• O � � N L. k�. �FO : �� `�m : i 39378 i . . � �•. .' �� o�,�'... ..; �� lh.,.S��NAL EN�� U z � � _ W N � J � � O U �O J >�� > U Yzow U � �LL w LL �� U N � W N��W � M�� In � 1�7 � � � �/ ,d �i i' � � I � % I � ;I ! � � I � �'� � � \� � �_i\ � � I\ �� %��1', � Z Q � W C� Q z Q � 0 � z Q � z 0 a � � W � � z 0 � W � W � N � � Z a J a W � Q Z � a � � 0 Z a � Z � Q � � SHEET 1 OF 1 � 0 Q � � J � U � z J J 0 U � � � L.L � Hydrologic Soil Group—Larimer County Area, Colorado � Q (512 Peterson St) � 0 0 493916 493924 493932 493940 493�'i8 493956 493964 493972 493980 493988 40° 34' S1" N I I I I I q0° 34' Sl" N � �� - � � _ '�' � � � � r +' ,� - *' n� .� � � � � �— , � r � � . ,� ` � +� � - - � ' - _ "� 1 1 . — � - - _ �, . � - '` - — �i ... ,_._a � . ' �� -- - — � �� K a � ' ' ' ' � 11 , _ — � � - . ��i� i � � � • _� �— � � I �M � � � � � � � � �,�r T, � r � *. = T� r _ �� t � r +� � Y � r ' � 1�� • L • " �t 'i . � - � , �` ,� f �, . : � � � � r �— � i �+ , - �� . , ,� � ' *" • �� t � '� � � �� Y .r — �r . . .�f .3,. rp, 5;01�. Mc�l- �J i�l�<�i�f Otl�Jt ��C V<i��fil,4� ��,�3�l5 4C:c�Qf=, � �� .y — � . • 40° 34' SO,� N m. �,� , I� _�—,1 I I � I I. _, 4°� �n� 5°" N 493916 493924 493932 4.93.4A0 4.93948 493.9r.�6 493964 493972 493.980 4.93998 3 3 � � a Map Scale: 1362 if pnnted on A landscape (11" x 8.5") sheet. '" v ° N Meters ° � 0 5 10 20 30 � � Feet 0 15 30 60 90 Map projection: Web Mercator Comer coordinat�: WGS84 Edge tics: UTM Zone 13N WG584 USDa Natural Resources Web Soil Survey 7/25/2022 � Conservation Service National Cooperative Soil Survey Page 1 of 4 Hydrologic Soil Group—Larimer County Area, Colorado (512 Peterson St) MAPLEGEND Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons � A o �o 0 B � B/D 0 C 0 C/D � D � Not rated or not available Soil Rating Lines ,�y A o � ■ C/D � D 0 Not rated or not available Water Features Streams and Canals Transportation � Rails ti Interstate Highways US Routes Major Roads Local Roads Background - Aerial Photography �,� A/D ,.�� B ,..,,� si� . r C ..as C/D ,ry D . w Not rated or not available Soil Rating Points � A ■ A/D ■I B ■ I aio MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24, 000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Larimer County Area, Colorado Survey Area Data: Version 16, Sep 2, 2021 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Aug 11, 2018—Aug 12, 2018 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. USDa Natural Resources Web Soil Survey 7/25/2022 � Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group—Larimer County Area, Colorado Hydrologic Soil Group 512 Peterson St Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 35 Fort Collins loam, 0 to 3 C percent slopes 0.3 100.0% Totals for Area of Interest Description 0.3 Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition 100.0% USDn Natural Resources Web Soil Survey 7/25/2022 r Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group—Larimer County Area, Colorado Aggregation is the process by which a set of component attribute values is reduced to a single value that represents the map unit as a whole. A map unit is typically composed of one or more "components". A component is either some type of soil or some nonsoil entity, e.g., rock outcrop. For the attribute being aggregated, the first step of the aggregation process is to derive one attribute value for each of a map unit's components. From this set of component attributes, the next step of the aggregation process derives a single value that represents the map unit as a whole. Once a single value for each map unit is derived, a thematic map for soil map units can be rendered. Aggregation must be done because, on any soil map, map units are delineated but components are not. For each of a map unit's components, a corresponding percent composition is recorded. A percent composition of 60 indicates that the corresponding component typically makes up approximately 60% of the map unit. Percent composition is a critical factor in some, but not all, aggregation methods. The aggregation method "Dominant Condition" first groups like attribute values for the components in a map unit. For each group, percent composition is set to the sum of the percent composition of all components participating in that group. These groups now represent "conditions" rather than components. The attribute value associated with the group with the highest cumulative percent composition is returned. If more than one group shares the highest cumulative percent composition, the corresponding "tie-break" rule determines which value should be returned. The "tie-break" rule indicates whether the lower or higher group value should be returned in the case of a percent composition tie. The result returned by this aggregation method represents the dominant condition throughout the map unit only when no tie has occurred. Component Percent Cutoff.� None Specified Components whose percent composition is below the cutoff value will not be considered. If no cutoff value is specified, all components in the database will be considered. The data for some contrasting soils of minor extent may not be in the database, and therefore are not considered. Tie-break Rule: Higher The tie-break rule indicates which value should be selected from a set of multiple candidate values, or which value should be selected in the event of a percent composition tie. 512 Peterson St USD,4 Natural Resources Web Soil Survey 7/25/2022 � Conservation Service National Cooperative Soil Survey Page 4 of 4 National Flood Hazard Layer FIRMette 105°4'36"W 40°35'S"N � 0 � � �Y.��r� � � �� 4 � �� r � _ ' � � - �e ,� � � ' � r � � .� i �r � 'i" � J � � � T � •.a r;��:�,�� _ � � � � ,`, � � � � �� - � �� , ` ,� � � �— � �, ° ,� .� ` j� �►, �'- ^ � � "f � ♦ � � � _l � �s a�� ! a � �� '��1�4� i�f'O�t1�lI1S' � � � . �'"�,c„�,h;_ _ ,4RE�CrF,,��P�l i � �' � •� { � '` _ , � �' � .�.- � � - - ,� �� . � � � � '� � r � � �. � � �r �. � �i 0 250 500 � � �� _ � � � �"��.I ._ r � • ..� � � ' � ii � � �� `-��-_'�` FEMA .A ��c{�- _�r`�1 �. _ .�� ' . ��+� rir��tii � � �� ` � . � ; �, ,� �� ,�' � ��'� �� el�� .� �* , � �r _ �� - � , �` � �r� � �`� T � i � � �� . � ,� 'li"` M "� , �, � '�r� �� ' � � �� . � �� i� << �.�` �-�`Ira��L7�a�i� �. � . • � � � � R -.�" .�i� �FL{:�� }L�„ HI�.Z�1F�C} � � � ,� _ • _ ,�� _ � l � � r _ � �;, �, c ;' ��i � r � d u' - � � ��1 �q �� a �� ,-� ' �+-� � e Legend SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT Without Base Flood Elevation (BFE) Zone A. V. A99 SPECIAL FLOOD With BFE or Depth zone nE. A0. AH. vE. AR HAZARD AREAS Regulatory Floodway OTHER AREAS OF FLOOD HAZARD 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mile zo„e x �� Future Conditions 1% Annual Chance Flood Hazard zone x Area with Reduced Flood Risk due to Levee. See Notes. zm,e x Area with Flood Risk due to Leveezo�,e o NOSCREEN Area of Minimal Flood Hazard zonex 0 Effective LOMRs OTHER AREAS Area of Undetermined Flood Hazard zone o GENERAL ---- Channel, Culvert, or Storm Sewer STRUCTURES i i i i i i i Levee, Dike, or Floodwall � Cross Sections with 1% Annual Chance ��•5 Water Surface Elevation e — — — Coastal Transect �v3�^^- Base Flood Elevation Line (BFE) Limit of Study Jurisdiction Boundary -- --- Coastal Transect Baseline OTHER _ — profile Baseline FEATURES Hydrographic Feature Digital Data Available N No Digital Data Available � � MAP PANELS Unmapped ^ The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. �� - .1 R�:"'�,`i � 1 � � �' : �� _+ � � �� , : � Y � • _1 � . ► � 11 � � � � • � . � R 1,500 This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 7/24/2022 at 6:02 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. a [ �� '�'�� e,�_�I � Feet �I .G'00o 105°3'S8"W 40°34'38"N 2,000 � U Basemap: USGS National Map: Orthoimagery: Data refreshed October, 2020 !'t ,�, ��`� ��, � � � � Fort,� °�ms 512 Peterson Street FCMaps �� s i��. . �! � 1 " . � �i � � ..... � : � � � r� � � , � R ` � . 1 • �� .4 � �� . • ,� _ � �i' �; , , .= �.. . :_ �'' ��;• j� ,�� ..a ,n ''1Y r �- � � -�'; y � t�� ` ._:.t�� j N• � � ,� �� -� � �' �,,�, ,�, i. ��. , -��.,. � � • . � �� r:.�- �,-r y �.� ` '�- _ . r ,� . � i ` �n- ` �` -- � � 1 r � M� �- �' �� w y� • y � . .� � ~ _ + ��« r� ,� �1�r � ;_� �• � � � � _" . , ,,._� , .. � ; • } �,,` . � r .�. �• t 1� � - ,. 4 • � �. �; '� . _. � �� '� �� '� i � � ' l � t �� •T.�^ � � �,� � - = � , ��y -,,� 7 � � � � , �,, �y �s.-1 - � � A � � � _ I � ..�.._ �`'� � -. - ,�� Y�._� � � _ � . �. *�-� � � i% �,�.. :�.- �.�',►3 - _ . ,, , , �' s�� '�'`: - � .. �.-- � � � , s � — t � �,�' ' ;'"' ti_ � . _ ._ . � �� `, „� . ' ^ . i t • �, � , . - �'- �... �� , � � . � � -�. _ ��-�� .� :. - �-� � - � , .,,. :� �. �. � �� . :� .� �� . ��' ��: ' ��aN.�r, �r� � ` � �- -. � - � �� i - - �i ��: � � ti � ��i ~ � � ��s �� L. L�liii'Z� �L � : �- � ,� 2.0 0 286.00 572.0 Feet This map is a user generated static output from the City of Fort Collins FCM< 3S 1984 Web_Mercator_Auxiliary_Sphere Internet mapping site and is for reference only. Data layers that appear on t map may or may not be accurate, current, or otherwise reliat y of Fort Collins - GIS �_�„�� i Legend FEMA Floodplain � FEMA High Risk - Floodway FEMA High Risk - 100 Year FEMA Moderate Risk - 1001500 Y� City Floodplains � City High Risk - Floodway City High Risk - 100 Year City Moderate Risk - 100 Year � _; City Limits Notes � � � �� _ -�: � '�''��'� ' � �, �� r+-� . �} _� �- 13� !�l • '! _ ' Composite Runoff Coefficient Calculations 512 Peterson Street, Fort Collins, CO „ � (c;Xa; ) c = �_� A, Where: C= Composite Runoff Coefficient C; = Runoff Coefficient for Specific Area (A;), dimensionless A; = Area of Surface with Runoff Coefficient of C;, acres or square feet n= Number of different surfaces to be considered A� = Total Area over which C is applicable, acres or square feet Equation 5-2 Historic & Developed Drainage Basin A Historic Drainage Basin B Developed Drainage Basin B Minor (2- and Minor (2- and Runoff Minor (2- and 10-yr) Major (100-yr) 10-yr) Major (100-yr) 10-yr) Major (100-yr) Surface Type Coefficientsl Area (sf) Composite CZ Composite C3 Area (sf) Composite CZ Composite C3 Area (sf) Composite CZ Composite C3 Hardscape or Hard Surface Concrete 0.95 635 500 580 Rooftop 0.95 1,295 690 1,514 Gravel 0.50 500 360 500 Total Impervious Area 2,430 1,550 2,594 Landscape or Pervious Surface Lawns, Clayey Soil, Flat Slope < 2% 0.20 417 5,102 4,058 Total 2,847 0.76 0.95 6,652 0.35 0.44 6,652 0.46 0.57 Notes: 1. Runoff coefficients per Fort Collins Stormwater Criteria Manual Table 3.2-2. 2. Composite runoff coefficient per Fort Collins Stormwater Criteria Manual Equation 5-2. 3. Frequency adjustment factor per Fort Collins Stormwater Criteria Manual Table 3.2-3. Table 3.2-3. Frequency Adjustment Factors Storm Return Period Frequency Adjustment (years) Factor (Cf) 2, 5, 10 1.00 25 1.10 50 1.20 100 1.25 Table 3.2-2. Surface Type - Runoff Coefficients Surface Type Runoff Coefficients Hardscape or Hard Surface Asphalt, Concrete 0.95 Rooftop 0.95 Recycled Asphalt 0.80 Gravel 0.50 Pavers 0.50 Landscape or Pervious Surface Lawns, Sandy Soil, Flat Slope < 2% 0.10 Lawns, Sandy Soil, Avg Slope 2-7% 0.15 Lawns, Sandy Soil, Steep Slope >7% 0.20 Lawns, Clayey Soil, Flat Slope < 2% 0.20 Lawns, Clayey Soil, Avg Slope 2-7% 0.25 Lawns, Clayey Soil, Steep Slope >7% 0.35 512 Peterson - drainage.xlsx Drainage Basin Runoff Calculations 512 Peterson Street, Fort Collins, CO Area Minor Major Initial/Overland Timel Travel Timez Final T� Intensity (in/hr)' Basin Flow (cfs)5 Basin Length Slope Minor to Major to Length Slope Channel Velocity tt Minor Tc Major Tc (acres) Composite C Composite C ( � (o � ( ) ( � ( � (o�o) Yp ( p � ( , ( � ( � 2-yr 10-yr 100-yr 2-yr 10-yr 100-yr ft /o min min ft T e f s min min min Historic A 0.010 0.76 0.95 55 1 4.7 2.1 NA 5.0 5.0 2.85 4.87 9.95 0.02 0.04 0.09 B 0.153 0.35 0.44 120 2 12.2 10.8 NA 12.2 10.8 2.05 3.50 7.72 0.11 0.19 0.52 Developed A 0.010 0.76 0.95 55 1 4.7 2.1 NA 5.0 5.0 2.85 4.87 9.95 0.02 0.04 0.09 B 0.153 0.46 0.57 80 2 8.5 7.0 65 1.5 grass swale 18.4 0.1 8.6 7.1 2.35 4.02 8.80 0.16 0.28 0.77 Notes: 1. Per Fort Collins Stormwater Criteria Manual Section 3.3.2. i.s��i.i-cxcf�� T' 3� Where: C= Runoff Coefficient, dimensionless C, = Frequency Adjustment Factor, dimensionless L= Length of Overland Flow, feet S = Slope, percent 2. Per Fort Collins Stormwater Criteria Manual Section 3.3.3. V _ 1.49 R2/3S1/2 n Where: V = Velocity, feet/second n = Roughness Coefficient, dimensionless R= Hydraulic Radius, feet (Hydraulic Radius = area / wetted perimeter, feet) S = Longitudinal Slope, feet/feet And L T� - vxeo 3. Per Fort Collins Stormwater Criteria Manual Section 3.3.4. A minimum T� of 5 minutes is required. T�-iso+10 4. Per IDF Table for Rational Method, Table 3.4-1 Fort Collins Stormwater Criteria Manual. 5. Per Fort Collins Stormwater Criteria Manual Equation 5-1 Q = CIA Where: Q= Peak Rate of Runoff, cfs C = Runoff Coefficient, dimensionless I = Rainfall Intensity, in/hr A= Area of the Basin or Sub-basin, acres 512 Peterson - drainage.xlsx Equation 5-1 PROPOSED DRAINAGE CONDITIONS; MODIFIED FAA METHOD' w/ Fort Collins IDF Project Name : Black Garage Project Location : 512 Peterson Street, Fort Collins, CO Input Variables Results Design Point 1 Design Storm 100-yr C= 0.57 Required Dry Well Volume Tc = 7.1 min 45 ft3 A = 0.153 acres Max Release RateZ = 0.72 cfs Inflow Outflow Storage Fort Collins 100-yr Qa„ Outflow Volume Time (min) Volume Adjustment 3 Volume Intensity (in/hr) fts Factor (cfs) (ft ) ft3 5 9.95 260 1.00 0.719 216 45 10 7.72 404 0.86 0.615 369 35 15 6.52 512 0.74 0.530 477 35 20 5.60 586 0.68 0.487 585 2 25 4.98 651 0.64 0.462 692 -41 30 4.52 710 0.62 0.445 800 -91 35 4.08 747 0.60 0.432 908 -161 40 3.74 783 0.59 0.423 1016 -233 45 3.46 815 0.58 0.416 1124 -309 50 3.23 845 0.57 0.411 1232 -387 55 3.03 872 0.56 0.406 1339 -467 60 2.86 898 0.56 0.402 1447 -549 65 2.71 922 0.55 0.399 1555 -633 70 2.59 949 0.55 0.396 1663 -714 75 2.48 973 0.55 0.394 1771 -798 80 2.38 996 0.54 0.391 1879 -882 85 2.29 1019 0.54 0.390 1986 -968 90 2.21 1041 0.54 0.388 2094 -1054 95 2.13 1059 0.54 0.386 2202 -1143 100 2.06 1078 0.54 0.385 2310 -1232 105 2.00 1099 0.53 0.384 2418 -1319 110 1.94 1117 0.53 0.383 2526 -1409 115 1.88 1131 0.53 0.382 2634 -1502 120 1.84 1155 0.53 0.381 2741 -1586 Notes: 1. Using the method described in Urban Storm Drainage Criteria Manual Volume 2. 2. Release rate per 2-yr historic flows (0.11 cfs for 0.153 acre). !022 AM yr-FAAModified-USDCM_Ft-Collins-I DF.xls aired Retention Volume Keefe Civil, LLC GEOTECHNICAL EXPLORATION FOR 512 PETCRSON STREET, CITY OF FORT COLLINS, LARIMER COUNTY, COLORADO FOR MIGHTY HAND CONSTRUCTION CDS ENGINEERINC CORPORATION LOVELAND, COLORAUO PROJECT NUMI3ER 22-1351 FEBRUARY 22, 2022 February 22, 2022 Project No. 22-1351 Jesse Applegate MIGHTY HAND CONSTRUCTION 141 Racquette Dr, Unit 2 Fort Collins, CO 80524 Dear Jesse, Enclosed is the report you requested of the geotechnical exploration for the proposed detached garage to be located at S l 2 Peterson Street, City of Fort Collins, Larimer County, Colorado. The site appears to be suitable for the construction of the proposed garage, provided the design criteria and recommendations given in this i�eport are followed. If you have any further questions concerning the information in this report, please contact this office. Respectiially, Reviewed by: �� a/� �i. Kevin F. Enclosures ��,r ;r � - a.• V TF'9 �E �!'� .a � " a��8: � .:�,� :e ; � ' i. �'� .`'�-s•-,� F4R AND ON BCHALF OF CDS ENGINECRING CORPORATION �� Marin Wood, Engineering Technician 165 2nd Street S.W. • Lovel�r�d, C� 80537 •(970) 667-8010 • Fax (970) 667-8024 • www.cds-eng.net : i �[�]�K�]��1��. Letter of Transmittal 'l,able of Contents Scope Site Investigation Site Location and Description Subsurface Conditions Foundation Recommendations Lateral Earth Pressures Slab Construction Conclusions ATTACHMENTS Location of Test Borings Symbols and Soil Properties Log of Borings Swell-Consolidation Test Results Summary of Test Results Post-Construction Site Preparation and Maintenance Placement of Compacted Fill Materials Pa�e i ii 1 l 2 2 2 3 4 4 Figure No. 1 Figure No. 2 Figure No. 3 Figure No. 4 Table No. 1 Appendix 1 Appendix 3 m 1 SCOPE 1�his report presents the results of our geotechnical exploration for the proposed detached garage to be located at the project site. The building is anticipated to be of typical wood frame construction. Slab-on-grade construction is anticipated for this structure. This exploration was conducted to provide recommendations pertaining to the type and depth of foundation system, allowable soil bearing pressures, groundwater conditions, and to identify any complications that may be encountered during or after construction due to subsurface conditions. This report has been prepared for the exclusive use of our client for the project discussed. If the building location or the scope of the project should change, CDS L='ngineering shall be notified prior to construction to review the report and provide alternate recommendations if deemed necessary. Additional borings may be required to provide the alternate recommendations. Additional fees may apply. SITE INVESTIGATION The field investigation perfonned on February 14, 2022, consisted of drilling, logging, and sampling one (1) test boring within the approximate building envelope at the site. The boring was drilled to a depth of twelve (12) feet. The location of the 'l�est Hole is shown on Figure No. 1. The boring location was established by a representative of CDS Engineering Corporation based on locations provided by the client. A graphical log of the boring is shown on Figure No. 3. T'he descriptions of the soils and/or bedrock strata are based, primarily, on visual and tactual methods which are subject to interpretation. The test boring was advanced using a truck mounted, four (4) inch diameter, continuous flight auger drill rig. Laboratory samples were obtained by driving a two and one-half (2'/2) inch diameter California-type, split barrel sampler twelve (12) inches (or as shown) into undisturbed soils with a 140-pound hammer falling thirty (30) inches. Ba�; samples of auger cuttings may have also been collected. Laboratory tests performed were - Swell-Consolidation, Natural Moisture and Natural Dry Densities. All tests were c�nducted in accordance with AS"1�M standards. A Summary of the 2 Swell-Consolidation Test Resulis is shown on Pigure No. 4. A Summary of Test Results is shown on Table No. 1. ITE LOCATION AND DESCRIP"I'ION The site is located in Fort Collins, south of East Mulberry Street, north of East Myrtle Street and on the east side of Peterson Street, Larimer County, Colorado. The site is in a developed urban subdivision with paved roads and utilities, and vegetation consists primarily of sod and trees. The site is relatively t1at. An existing house and detached garage are located on this property. SUBSURFACE CONDITIONS Based on the boring drilled within the proposcd building footprint, the subsurface conditions at the site consist of clay. Groundwater levels were recorded after completion of the drilling operations. During our tield exploration groundwater was not encountered in the test boring. The groundwater table should be expected to fluctuate throughout the year depending on seasonal moisture variations. Refer to the Log of Borings, Figure No. 3, for additional details specific to each boring. Although evidence of underground facilities such as, but not limited to, septic tanks/fields, cesspools, cisterns, foundations, utilities or mining operations were not observed during our exploration, such features could be encountered during construction. If unexpected fill or underground facilities are encountered, proper remediati�n should be taken. Alternate recommendations, other than those provided in this report, may be required. FOUNDATION RECOMMENDATIONS The type of foundation best suited for a particular building site is dependent not only on the characteristics of the soil and rock but also depends on the type of structure, depth to groundwater, the proposed depth of excavation, and owner preference. The recommendations that follow are primarily based on the type of soil or bedrock encountered. Based on the conditions observed in the field and laboratory tests, we recommend the foundation be a continuous spread footing and isolated pad foundation. 3 Continuous Spread Footin� and Isolated Pad Foundation The foundation should be a continuous spread footing and isolated pad foundation designed for a maximum allawable bearing capacity of 1500 pounds per square foot (dead load plus full live load) and a minimum dead load kept as high as practical to help counteract the swelling should the subsoils become wetted. The foundation is to bear on the native, undisturbed clays, and not on unapproved fill, topsoil, or frozen ground. The bottom of all foundation components should be kept at least thirty (30) inches (or per local code) below finished grade for frost protection. The open excavation should not be lefi open for an extended period of time or exposed to adverse weather conditions. Excessive wetting or drying of the excavation shauld be avoided during construction. Excavations that are inundated with water may soften and require re-compaction, or removal, of the exposed subgrade soils. The completed open excavation should be observcd by a representative of CDS Engineering Corporation in order to verify the subsurface conditions from test-hole data. LATERAL EARTH PRESSURES Lateral earth pressures are forces exerted on earth retaining structures and foundation components, by the soil. The pressure exerted is influenced by wetting of the backfill soils, type and compaction of the backfill and the methods used to compact the backfill. For the soils, above the free groundwater surface at this site, we recommend the foundation components be designed using the following equivalent fluid pressures. • Active Pressure = 35 pcf • At Rest Pressure = 50 pcf These values assume that the positive drainage will be maintained throughout the life of the structure. It is our opinion that the on-site soils encountered could be used as backfill inaterial against foundation walls. The soils shall be moisture conditioned and well pulverized so that all fragments are smaller than six (6) inches. Refer to Appendix 1 for additional backfill information. If there is opportunity for the backfill soils to becoine saturated, we shall be notified to revise the minimum equivalent fluid density. Thesc values do not include a factor of safety or take into account any surcharge loading. 4 SLAB CONSTRUCTION Changes in the moisture contents may result in consolidation or swelling of the subsoil, resulting in differential slab movement. The soils encountered and tested at this site exhibit no swell potential as moisture contents are increased. According to the Guideline for Slab Perfi�rmance Risk Evaluation and Residential Basement Floor System Recommendations, developed by the Colorado Association of Geotechnical Cngineers, slab performance risk at this site would be considered low. Slabs placed on the native, unaltered soils at this site may experience slight heaving and cracking, but should not be excessive. If slabs-on-grade are chosen and the owner is willing to accept the risks of potential damage from slab movement, slabs should be constructed to be "free-floating" and isolated from all structural members ofthe foundation, utility lines, and partition walls. There should be a minimum two (2) inch void constructed below partition walls located over slabs-on-grade. The void should be increased to four (4) inches for slabs placed on potentially expansive bedrock stratum. Eliminate under-slab plumbing where feasible. Where such plumbing is unavoidable, it should be pressure tested before and after slab construction to minimize leaks which would result in wetting of the subsoil. Failure to allow the slab to float independently could result in functional, structural, architectural, and utility line damage. All slabs should be scored into maximum 225 square foot areas or maximum dimensions of tifteen (15) feet with a minimum depth of one (1) inch to localize and control any cracking due to heaving. Any slabs less than thirty (30) square feet should be scored at least once in each direction. The minimum slab thickness should be four (4) inches, with four (4) inches of clean, washed gravel under the slab. Slabs should be reinforced with welded wire fabric, or equivalent, to help control cracking and separation. Fiber mesh shall not be considered an equivalent substitute for the welded wire fabric. Slab-on-grade areas should not be tinished for at least two (2) years (preferably three (3) to five (5) years) from the time of substantial completion, to allow for initial movement. CONCLUSIONS The soils encountered at this site exhibit no swell potential as moisture contents are increased. Future owners should be cautioned of the risk oPdamage caused by the introduction of 5 excess water to the soils. All new and future owners should be directed to those items under "Post- Construction Site Preparation and Maintenance" in Appendix 1, included in this report. Our experience lias shown that damage to foundations usually results from saturation of the foundation soils caused by improper drainage, excessive irrigation, poorly compacted backfills, and leaky water and sewer lines. The elimination of the potential sources of excessive water will greatly minimize the risks of moveinent at this site. Homeowners must assume responsibility for maintaining positive drainage around the structure and incorporating appropriate landscaping that will not interfere with the positive drainage. It is recommended that a copy or summary of this report be provided to any new or future owners of this property. A copy of A Guide to .Swelling Soils for Colorado Homebuyers and Homeowner.s, Colorcrdu Geologicul Survey Special Publicution 43 should also be provided to any new or future owners of the property. The findings and recommendations of this report have been obtained in accordance with accepted professional engineering practices in the field of Geotechnical Engineering. However, standard Geotechnical Engineering practices and related government regulations are subject to change. The recommendations provided in this report are for the exclusive use of our client and are not valid for use by others. If the construction takes place approximately three (3) years beyond the date of this report, we should be contacted to review the information with regard to updated governmcntal requirements or industry standards. Additional fees may apply. There is no other warranty, either expressed or implied. We do not guarantee the performance of the project in any respect, but only that our engineering work and judgments rendered meet the standard of care of our profession. "I'his report applies only to the type of construction anticipated in the area tested. The current technology is not at a stage where a guarantee of� "absolutely no damage" can be assured by design and construction practices. JL E.MULBERRY STREET ,�� _ _ __._ _ T y�,.. � �.� . . � � W � � �� . � '. . ' . � � z � . .� �. p i �. � ,�� li � �i�?' i :>,• 1 wa �>- �-,.i? �. . '� ,- 'i- , ' _, ; ,;�� T��y%!Q�'�! "1�_� � � � � �r� • ��' �i vhj� �,.�� , w!� ; y- � }.' i� - : � . '`"�, "� �.-�i•' 1 . +t' ^t �� S �. � . . f *. . . ' - �` ' ..�1 _ � �.�. ,�, „r,.�'�� ". `�"�'� .��: r � � �� — - .. .-:�, �i �w � - � °� � :.� -�� _ .; — _ M,, ..+'"' u � �� , t; �,'i,:- , � y p `�''' .. • x� i` �. : T �,,' .� � �� .�,t� �.�' �,•� �: �, ;" �i =..'`.{��a�� ',,,�'-'� �;.4'�, 'Yr :.,,y!� �_�• l�� ~ • y . ,e... `` `�:�-' s"�, ��.ti�ry. `•�. - - `sn � • I i' � � . � . Ht. T �. i � ..-�;�� ,i _i.- t 'd . . F' ��. �� .....` i'� �� } . _ t�' _ r �-- �- .• �r ` 4�. �a . '�Si,, . ,rr-- '� ,,y �_ , �1r ..s, ' f��/ '�, -��. ,.. .�� -- � ''•`i� ;,,�f'"; �' , �� ,�� . �� . f��. r �'r�� f� � . .. �_>•� �`4 - i, - ��°"�"'�� :, =:��, �. � �� . EXISTING I10USE y. � '� FXISTING ' GARAG[ �1. r��w�. .. . c Vr .1 , �`. � ifi i � ■ *+r..:;:i�..�� - - t •-, ' ' �� 4 ,f ' 4,. - - + ` , � � ,;,e � ' f' � - � , � . '�� • � "'if .- , . � �.. � � ,�� • '� t { ,� �`�� ' ,� .'� ` � .i A"' _ � -� , x �. - E � �� ,�, , � - �.' _ ,. � .�� .� r: � . � �� ,,,. a, �-� �;�. �- ., , ,; - , � ��,.:.�:��: � �i �. _ , :� "�e t'�'' � �� *� � . - _ I � ' . .. . � . .ww: �. # : R� . � � � J :. L . � , � t. � � Rµ , _ r� . :c , y . � •. "' �'� �� '�: :' Ir !, �� v - . � � � ` � , ' �I � . .. � � ' _ . . F� .- ' �•` . � � , , ' . f. : -t � � SCALE 1 4a` ��:�"� . �.� .` � ♦� }�� . . �, ' t .� Location of Test Borings Client: Mighty Hand Construction Project: 512 Peterson Street, Fort Collins, Larimer County, Colorado , Engineering Corporation 1fi5 2nd St. S.W., Lovaland, Colorado 80537 Tele: (970) 667-8010 � � Date . - �' �. r I � , _ - -� . �,i �.. _ , •r,�:j ' ,,;� �:,y.,. . ,7 .��' . .._ .� �I � i � � �' , �, ,ii �'! �� , }' :.� .N :�� :� -, �� . rr- � .'e`-'.. �l i'� � i " I I , +� . i I� I• . ,'I�� ; y�_ � 's . .� � � � .I * «�, 02/22/22 Project No Drawn By: Figure: 22-1351 MEW 1 Svmbols �c Soil Pro erties � FIGURE N0. 2 .,... . , a. ' Gravel Sand N/12 C",LIFOP,N!", N/12 SPLII SP001�1 THIN WALLtU (SHtLE�Y) Wea �hered Eecirock _ ] Siltstone I BAG SAI�PLE PITCI-IER SAMPLE r -� I Igneous & Metamorphic rr r r Penetration Resistance and Strength Classifications are Based on The Standard Penetration Test Number of Blows Per� foot N * 0-4 4-10 10-30 30-50 50+ Relative Density C:ohesionless Soils Very Loose Loose Medium Dense Very Dense * BLOWS PER FOOT - BLOH�S OF 140 LB. HAMMER DROPPED 30 IN. TO DRIVE SPLIT SPOON OR CALIFORNIA SAMPLER 12" (IN.) (ASTIvI DL586-67) �' EQUIVALENT TO PP/2 AND Qu/2 Consistency Cohesive Soils Soft Firm Stiif Very Stiff Hard Approximate Cohesion ksf** Less than �.5 0.5-1.0 1.0-2.0 2.0-4.0 Greater than 4.0 ��i� ��i.�g 165 2nd St. S.FP. � � � � � � � �� Lovela� d, j 0 80537 '£ele: 970 667-8010 �o D � o -� m = � �T � m r O � 5 FT 10 FT. 15 FT. 20 FT. 25 FT. 30 FT. TH-1 35 FT. �CLAY: sl. silty, sl. sandy, tr. calc, brown, damp to moist, firm to stiff Borings drilled 02/14/22 using a 4" diameter, continuous flight truck mounted drilling rig. � Goundwater @ drilling All soil and/or rock contacts shown on borinq loye we approzimate and roprosent subsurtoee eondklons at time of drlllfnq. Borinq loqs a�d Iniartnatlon presented on loqs are subJect to dlscusalon and Itmltatlone of thle report. Boring Log , Date: Client: Mighty Hand Construction Project No. Project: 512 Peterson Street, Fort Collins, E n g i n e e r i n g Larimer County, Colorado Corporation Drawn By: 165 2nd St. S.W., Lovelond, Cdorado 80537 Tele: (970) fi87-8010 Figure: � o � m D � o � n cT ITl = m m r O � 5 FT. 10 FT. 15 FT. 20 FT. 25 FT. 30 FT. 35 FT. 02/22/22 22-1351 MEW 3 SWCLL / CONSOLIDATION TF.ST CURVES Client: Mighf liand Constructian Project: 512 Peterson Street, Fort Collins Project No.: 22-1351 Boring: "I'H-I Description: Clav, sl, silty, sl. sandy, bmwn, dantp, tirm Depth, ft: 3' Water Content: 7.1% Swell (%):* -0.I Dry Density, pcf: 100.9 Approximate Swell Pressure, psf: ino �, 5 4 - � 3 -- - - - I � 2 --- - �- 0 � I - -I � , U Q _ _ - _ - � _ : � -I I I , 0 � -2 - ------ -- — - --- — - - � -3 - - - — — i_ -4 - — - - - — - I _S _ . ------ - -- --_ _--- - -- ' �� -G I3orin�: TH-I Description: Clay, sl. silty, sl. sandy, tr. calc, brown, damp, sfifi� Depth, ft: 7' Watcr Cnntcnt: 7.7% Swell (°/�):* -0.7 Dry Density, pcf: 104.4 Approximate Swell Pressure, psf: IUO 1'ressurc, psf 1000 10000 Pressurc, psf ioon �; � 5 --- - - — - -- - -- - 4 — -- - — - - - 3 -- - — — -- � 2 -- e � l -- - - a � 0 -- - - � � -I - --- _- — --- 0 i -2 - - - _ - � - I - --- -- -- -- -4 - - - — - - - - --- - - - -5 --- - - — - -- - - -G CDS Engineering Corporation ' negative values indicate consolidation figure 4 VI �" J � � W � H W � � O rN F�. � � � � N � � M � i N N 0 Z .� U N O � a � O Z W J m a � C O � (0 (II N .` � U U U � a� � moo C N � .y � � N � f0 � •� a � a�i ' a � N � w � r c � a c c � N � U � N .r � � a o J � � � J o a � m � � o 0 v Q O O � ., u� �n � N � N � a` a a� 3 � « � � � 0 0 � � O O Z O w p> � N '� �i O d' � n O Q « Q � � � � z f0 � � ^ �--- I�• � � o �{ <p � ... I� f� � Z � c �' '� N N o N N r � � N � N M o � � � �k a L � � M � � 0 01 C � O Z � � � m � O � a� a� L � � 0 .@ v �o N O U N � '� c N a� m > a� > .m rn a> Z a> rn co L � 3 � v a� � �U N a � rn c � 3 0 APPENDIX 1 POST-CONSTRUCTION SITE PREPARA'I'ION AND MAINTENANCE Backfill When encountering potentially expansive or consolidating soils, measures should be taken to prevent the soil from being wetted during and after construction. Generally, this can be accomplished by ensuring only minimal settlement of the backfill placed around the foundation walls. It should be understood that some backfill settlement is normal and should be anticipated. Areas that do settle should be repaired immediately to prevent ponding around the foundation. Water may need to be added to backfill material to allow proper compaction -- do not puddle or saturate. Backfill should be mechanically compacted to at least 90% of Standard Proctor. Compaction requirements could be veritied with tield tests by tlle F;ngineer. It is the contractor's responsibility to contact the engineer for such tests. Surface Draina�e The final grade should have a positive slope away from the foundation walls on all sides. At minimum, the slope shall meet the requirements of the governing Building Code. Where site grading allows, we recommend a minimum of six inches (6") in the first five feet (5'). Downspouts and sill cocks should discharge into splash blocks that extend beyond the limits of the backfill. Splash blocks should slope away from the foundation walls. The use of long downspout extensions in lieu of splash blocks is advisable. Surface drainage away from the foundation shall be maintained throughout the lifetime of the structure. Lawn Irri ag tion Do not install sprinkler systems next to foundation walls, porches, or patio slabs. If sprinkler systems are installed, the sprinkler heads should be placed so that the spray from the heads under full pressure does not fall within five feet (5') of foundation walls, porches, or patio slabs. Lawn irrigation must be carefully controlled. If the future owners desire to plant next to foundation walls, porches, or patio slabs, and are willing to assume the risk of structural damage, etc., then it is advisable to plant only flowers and shrubbery (no lawn) of varieties that require very little moisture. These flowers and shrubs should be hand watered only. Landscaping with a plastic covering around the foundation area is not recommended. Check with your local landscaper for fabrics which allow evaporation when inhibiting plant growth when a plastic landscape covering is desired. Experience shows that the majority of problems with foundations due to water conditions are generally due to the owner's negligence of� maintaining proper drainage of water from the foundation area. The future owners should be directed to pertinent information in this report. REV 7/30/13 APPENDIX 3 GENERAL SPECIFICA'TIONS FOR "THE PLf10EMENT OF COMP�ICTED PILL MATERIAL PLACED BELOW A STRUCTURE Moisture-Density Determination Representative samples of the materials to be used for fill shall be furnished by the contractor at least seventy two (72) hours prior to compaction testing. Samples with higher moisture contents will require extra timc for test results due to the required drying for sample preparation. "I'ests to determine the optimum moisture and density of the given material will be made using methods conforming to the most recent procedures of ASTM D698 (standard Proctor) or other approved methods, whichever may apply. Copies of the Proctor Curves will be furnished to the contractor. These test results shall be the basis of control for the tield moisture/density tests. Materials The soils used for compacted fill shall be selected or approved by the Cngineer. The material shall be free of vegetation, topsoil or ai�y other deleterious materials. The material should be relatively impervious and non-swelling for the depth specified in the soils report with no material greater than six (6) inches in diameter. Site Preparation All timber, logs, trees, brush and rubbish shall be removed from the area and disposed in a manner approved by the local governing agency. All vegetation and a substantial amount of topsoil shall be removed from the surface upon which the till is to be placed. Where applicable, the surface shall then be scarified to a depth of at least six (6) inches, moistened or dried as necessary to allow for uniform compaction by the equipment being used. The scarified surface shall be compacted to not less than 95% of maximum dry density based on ASTM D698, or to such other density as may be determined appropriate f'or the materials and conditions and acceptable to the Engineer. Fill shall not be placed on f'rozen or muddy ground. Moisture The fll material, while being compacted should contain, as nearly as practical (typically +/- 2%), the optimum amount of moisture as determined by the Standard Proctor Test ASTM D698, or other approved method. The moisture shall be �miform throughout the fill material. The effort required for optimum compaction will be minimized by keeping soils near optimum moisture contents. Preezing temperatures and/or inclement weather conditions may impede moisture control and compaction operations. Placement of Fill The Ueotechnical Engineer shall be retained to supervise thc placement af fill material. The fill material shall be placed in uniform layers and be compacted to not less than 95% of maximum dry density based on ASTM D698, or to such other density as may be detertnined appropriate for the materials and conditions and acceptable to the Engineer. Prior to compacting, each layer shall have a maximum loose layer height of twelve (12) inches (or as dictated by the compaction equipment and/or soil conditions) with the surface relatively level. Test areas are recommended to determine the optimum layer thickness. "Chinner lifts may be necessary in order to achieve tlie required compaction. Compacted layer thickness shall not exceed six (6) inches. Each twelve (12) inches of compacted fill shall be approved by the Engineer prior to placing succeeding lifts. Pill shall be compacted with machinery appropriate for the type of earthen material being installed. Granular materials shall be compacted with vibratory type machinery. Clay and silt material shall be compacted with a sheepsfoot or other segmented pad type compaction equipment. "Wheel rolling" is not considered an appropriate method to achieve the recotnmended compaction specifications. "Whecl rolling" is not recommended for extensive areas or depths and cannot be relied upon to give uniform results. Moisture and Density Testing It is the contractor's responsibility to contact the Cngineer with a minimum of 24-hours notice to schedule compaction testing. The density and moisture content of each layer of compacted fill will be determined by the Engineer, or qualified technician, in accordance with ASTM D6938 (nuclear method), or other approved method. If the tests show inadequate density, that layer, or portion thereof; shall be reworked until the required conditions are obtained. Additional layers shall not be placed until each underlying lift has been approved. The results of all density tests will be furnished to both the owncr and the contractor by the Engineer.