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CC - Stormwater Report
Southern Highlands Phase 2 Subdivision STORMWATER MANAGEMENT ON-SITE DISPOSAL REPORT JOB # BE -382-1504 July 2015 PREPARED BY: HORROCKS ENGINEERS NAMPA, ID TABLE OF CONTENTS INTRODUCTION 1 EXISTING CONDITIONS HYDROLOGIC ANALYSIS I EXISTING SITE CONDITIONS 1 POST -DEVELOPMENT STORM DRAINAGE ANALYSIS 2 PROPOSED SITE CONDITIONS 2 RUNOFF VOLUME 2 - Storm Duration 2 Rainfall Intensity 2 STORM WATER MANAGEMENT SYSTEM 3 CONVEYANCE 3 WATER QUALITY 5 INFILTRATION 6 SYSTEM MAINTENANCE 6 SUMMARY 7 LIST OF TABLES Table 1 - Drainage Areas Table 2 - Curb and Gutter Flow Table 3 - Pipe Flow Table 4 - Seepage Beds APPENDIX A. VICINITY MAP B. GEOTECHNICAL INVESTIGATION C. POST -DEVELOPMENT DRAINAGE AREAS MAP AND STORM DRAIN CALCULATIONS D. RATIONAL METHOD RUNOFF C -COEFFICIENTS E. REGIONAL RAINFALL CURVE CHART 3 5 5 6 INTRODUCTION This report addresses the hydrologic analysis of the stormwater runoff generated by the development of the proposed on-site private improvements within the proposed Phase 2 of the Southern Highlands development, located in Ada County, Idaho. The analysis includes the design of the required water quality and retention/percolation facilities in compliance with the engineering standards set forth by the Ada County Highway District (ACHD) Policy Manual Section 8000 and the Construction Storm Water Management Program (CSWMP) for City of Meridian Construction Projects. The proposed public right of way improvements are addressed in the contract documents package to the ACHD. Please refer to the submitted Construction Drawing set of plans for this project for design configuration of the stormwater system. EXISTING CONDITIONS HYDROLOGIC ANALYSIS The proposed development is located in the NE '/4 of Section 32, Township 3 North, Range 1 East, Boise Meridian, City of Meridian, ADA County Idaho. Please see the attached Plat map. The site is found near of the intersection of E. Taconic Dr and S. Eagle Rd. EXISTING SITE CONDITIONS The existing site consists of roughly graded roads and building pads adjacent to the already completed Southern Highlands phase 1. The site is divided in two sections by a slope that creates an upper bench. The bench is generally at elevation 2704. The slope accounts for The Uppermost tier is generally at elevation 2704. A significant slope accounts for approximately 18ft of elevation loss. The remaining majority of the site is then at elevation 2678 to 2682. The roadway and mass grading that was completed prior to this phase generally directs stormwater to the north. The lower portion of the site has some variation in elevation, but can generally be considered flat. Stormwater runoff from the site generally does not concentrate and remains diffuse flow over undeveloped open space where it dissipates and naturally infiltrates. There are existing gravity irrigation ditches that exist on the west and north boundaries that may intercept stormwater runoff, albeit not by design. Per the soils report, no groundwater was detected in test pits in proximity to any designed BMPs. The project geotechnical report indicates that once exposed, the Infiltration rates of the on-site poorly graded gravels with sand are anticipated to be 12 inches per hour. For the purpose of design, we are using a maximum infiltration rate of 8 inches per hour. Groundwater depths and infiltration rates should be confirmed during construction. See Appendix B for geotechnical report and coordination. POST -DEVELOPMENT STORM DRAINAGE ANALYSIS PROPOSED SITE CONDITIONS The proposed project watershed consists of four (4) basin areas where drainage is collected and routed to infiltration facilities. All drainage within the basins flows overland where it is then collected in the streets and conveyed by curb and gutter and intercepted by inlets and subsurface pipe networks where required. Basins 1 and 2 are routed to infiltration facilities where drainage is first intercepted by a sand and grease trap. Basins 3 and 4 are intercepted by temporary drainage swales and routed to temporary detention ponds and will be collected by infiltration facilities when future phases are completed. See Table 1 for drainage basin design information. RUNOFF VOLUME To determine the conveyance and storage requirements, the runoff volumes were calculated based on the storm duration and intensities, in accordance with ACHD Policy Manual Section 8000 and CSWMP for City of Meridian requirements. The Policy Manual indicates that the Rational Method is to be used for calculating peak flow rates for areas smaller than 100 -acres. The following equation is the Rational Method with variable descriptions. Q = C I A where: Q = peak flow rate (cfs) C = Non -dimensional runoff coefficient for paved, concrete or housetop areas the C - Value was assumed to be 0.95. For grass areas, the C Value was assumed to be 0.20. A cumulative C value of 0.40 was used for calculating the runoff of all drainage basins. I = Average rainfall intensity (in/hr) A = Size of the contributing area (ac) The Policy Manual was referenced to determine the ACHD recommended runoff coefficient for use in the Rational equation. Storm Duration Section 8006.1.1 of the ACHD Policy Manual and indicates that a storm duration of 1 hour is to be used when using the Rational Method for calculating peak discharge. Rainfall Intensity Exhibit B of Section 8000 includes an Intensity -Duration -Frequency Curve. The storm duration and a return period of 25 years was used for primary conveyance systems K (Policy Manual, Section 8000, Table 1). Likewise, for secondary conveyance systems the return period used is 100 years. Because of the conditions of the site, the primary and secondary conveyance systems to the infiltration basins are the same and functions for the 100 year return period. Table 1 - Drainage Areas Area Size 100 -yr Event Event Duration Time of Concentration Runoff Coefficient Runoff Volume Peak Runoff Flow Rate BMP 1 13.86 AC 2.62 in/ hr 1 hr 15 Min. 0.4 22,970 CF 14.53 CFS SB 1 2 4.13 AC 3.11 in/hr 1 hr 10 Min. 0.4 7,081 CF 5.13 CFS SB 2 3 1.70 AC 3.11 in/ hr 1 hr 10 Min. 0.4 2,817 CF 2.11 CFS TP 3 4 1.00 AC 3.11 in/ hr 1 hr 10 Min. 0.4 1,657 CF 1.24 CFS TP 4 Table 1 shows the total runoff expected during the 100 -yr event and the size of the drainage areas, as well as the distribution of the runoff volume to each area. Sediment is not accounted for in these volumes. The actual areas were calculated as opposed to using the "Thompson's Rule" for more accurate results. STORMWATER MANAGEMENT SYSTEM CONVEYANCE The Policy Manual indicates that primary conveyance systems should convey the design storm with maximum treatment and minimum impact or inconvenience to the public. To determine the maximum hydraulic conveyance capacity of the street gutters, Izzard's Manning Equation was used (ACHD Policy Manual 8008.1). ACHD requires that the 10 -yr storm be conveyed within the roadway without overtopping the back of curb. T= Qn 0.56SXSX 3 where: Q = Discharge (cfs) Z = 1 /Sx Sx = Pavement cross slope (%) d = depth of water at face of curb (ft) S = Longitudinal grade of street (%) n = Manning's roughness coefficient The minimum roadway slope used for the project is 0.45% which yields a roadway capacity (half -width) of 3.40 cfs without overtopping. Table 2 shows the maximum flow to each sub -basin (inlet area) for a 10 -year storm event. See Appendix C for the drainage area map. Table 2 - Curb and Gutter Flow Sub -Basin Area (so Area (ac.) 125 yr (inlhr) C Q 10 yr (cfs) S(%) 1A 20,503 0.47 2.37 0.4 0.446 0.45 1B 63,643 1.46 2.37 0.4 1.385 0.45 1c 69,659 1.60 2.37 0.4 1.516 0.45 1D 91,732 2.11 2.37 0.4 1.996 0,45 1 E 72,857 1.67 2.37 0.4 1.586 0.45 1F 33,002 0.76 2.37 0.4 0.718 0.45 1G 93,689 2.15 2.37 0.4 2.039 4.00 1H 146,430 3.36 2.37 0.4 3.187 4.00 2A 73,486 1.69 2.37 0.4 1.599 0.45 2B 8,570 0.20 2.37 0.4 0.187 0.45 2C 64,124 1.47 2.37 0.4 1.396 0.45 2D 13,942 0.32 2.37 0.4 0.303 0.45 3 73,386 1.68 2.37 0.4 1.597 0.45 4 43,535 1.00 2.37 0.4 0.947 0.45 PIPE FLOW Manning's equation was used to determine the minimum pipe sizes necessary to convey the 25 -year storm event (Policy Manual, 8012.6). 4 Table 3 shows the flows in each pipe based on the runoff form the sub -basins shown in Table 2. Table 3 demonstrates that the pipes are adequate to handle the runoff for the design storm. Table 3 - Pipe Flow Pipe Length (ft) Inlet Invert (ft) Outlet Invert (ft) Slope (%) Diameter (inches) Manning's n Peak Flow (cfs) Velocity (ft/sec) Capacity (cfs) Flow Depth (ft) P1 198.66 2678.10 2677.11 0.5000 12.000 0,0110 2.31 4.19 2.97 0.66 P2 338.77 2676.61 2675.25 0.4000 18.000 0.0110 7.53 5.07 7.87 1.18 P3 154.89 2675.25 2674.63 0.4000 18.000 0.0110 7.53 5.06 7.85 1.18 P4 27.09 2674.63 2674.36 1.0000 18.000 0.0110 11.04 7.92 12.39 1.10 P5 6.50 2674.36 2674.26 1.5400 18.000 0.0110 12.87 9.75 15.40 1.05 P6 3.92 2675.25 2675.00 6.3800 12.000 0.0110 3.55 12.23 10.63 0.40 P7 5.06 2678.15 2678.10 0.9900 12.000 0.0110 2.38 5.56 4.19 0.53 P8 6.88 2677.80 2677.62 2.6200 12.000 0.0110 3.28 8.67 6.81 0.48 P9 25.80 2677.62 2677.11 1.9800 12.000 0.0110 5.81 8.78 5,92 0.73 P10 24.13 2677.86 2677.62 0.9900 12.000 0.0110 2.27 5.66 4.20 0.49 P11 31.03 2672.07 2671.76 1.0000 12.000 0.0110 2.01 5.54 4.21 0.45 P12 5.50 2674.26 2674.18 1.4500 18.000 0.0110 12.87 8.36 12.97 1.22 P13 15.72 2671.76 2671:60 1.0200 12.000 0.0100 4.84 6.79 4.67 0.79 WATER QUALITY A permanent water quality facility must be constructed to reduce contaminants that enter the storm system. Consequently, grease/sand traps are proposed upstream of each infiltration facility and seepage bed, in accordance with Idaho Standards for Public Works Construction Standard Drawing SD -624. Drainage Area 1 utilizes a 1,000 gallon dual chamber structure with two cleanout lids. The interior of each structure will have baffle walls. The throat of the baffles will be spaced at 36in in order to maintain a maximum velocity of 0.5 fps with a flow of 5.65cfs. Drainage Area 2 utilizes a 1,000 gallon dual chamber structure with two cleanout lids. The interior of each structure will have baffle walls. The throat of the baffles will be spaced at 20in. The trap will not exceed the 3.33 CFS maximum flow for the 1,000 gallon standard. 5 INFILTRATION When the on-site improvements are constructed, the increased impervious areas will contribute to the greater flows from stormwater surface runoff. This volume of water will be contained and re -introduced to the groundwater system through the design and implementation of on-site seepage beds. Table 4 shows the seepage bed dimension requirements to provide the needed volume to accommodate the 100 -yr event. Table 4 - Seepage Beds Seepage Drainage Drain Rock Storage Time to Bed Area Depth Width Length Volume Drain #1 DA 1 9 FT 75 FT 85 FT 22,970 CF 4.9 hrs #2 DA 2 6 FT 30 FT 98 FT 7,081 CF 3.3 hrs The onsite seepage beds adhere to the minimum vertical separation of 3 ft from the bottom of the system to the seasonal high groundwater elevation. Water is conveyed to the seepage beds via gutter flow where it is intercepted by inlets and routed through pipes. The seepage beds will drain within 24 hours with an infiltration rate of 8.0" per hour based on the information provided in the soils report. Because the design infiltration rate is 8.0" per hour, the design does not require that the storage volume be adjusted for sediment (Policy Manual, 8012.3.4 The resulting infiltration times presented indicate that all of the proposed seepage beds operate satisfactorily, discharging 90% of the accumulated volume in less than 24 hours. SYSTEM MAINTENANCE The ACHD facilities areas that are accessible to ACHD maintenance crews for monitoring and for maintenance and cleaning. Proper maintenance should include maintenance of the sand and grease trap located upstream of the seepage beds. R SUMMARY In conclusion, the stormwater facilities proposed are designed to meet the ACHD requirements for the 25 -yr and 100 -yr storm events in conveyance and volume capacities, where applicable. Design of the stormwater management facilities are in compliance with the ACHD Standards as set forth in Section 8000 and the Construction Storm Water Management Program (CSWMP) for City of Meridian Construction Projects. Appendix A. VICINITY MAP 1-84 o E OVERL ND RD. 0 0 E VICTORY RD. o � J W U O U) w E AMITY RD. co U co PROJECT LOCATION E LAKE HAZEL RD. VICINITY MAP (NTS) B. GEOTECHNICAL INVESTIGATION �4 sTRa-ra A PearessIONiu SUMCLS CORPORATION :rrt gvl;[X From 4 -Ac G�ro"gd UP Mr. Chad Hamel BHH Investments 1, LLC 1025 S. Bridgeway Place, Suite 290 Eagle, Idaho 83616 chamel@boisehunterhomes.com Dear Chad: May 27, 2014 File: B014105A RE: Geotechnical Engineering Evaluation Southern Highlands Subdivision East Taconic Drive Meridian, Idaho STRATA, A Professional Services Corporation (STRATA) is pleased to present our authorized limited geotechnical engineering evaluation for the proposed Southern Highlands Subdivision to be located north of East Taconic Drive in Meridian, Idaho. Our evaluation's purpose was to explore the subsurface conditions in the proposed development area and provide geotechnical recommendations to assist project planning, design and construction for the planned residential development including public roadways and associated infrastructure. The attached report summarizes our field and laboratory test results, and presents our geotechnical engineering opinions and recommendations. The following report provides specific geotechnical recommendations for preparing the site, including undocumented fill removal, earthwork activities, pavement design and stormwater design recommendations. It is our opinion that geotechnical continuity with the project team throughout construction will help identify undocumented fill during earthwork to allow its removal and replacement with structural fill. The project design, owner, and construction team must read, understand and implement this report in its entirety. Portions of the report cannot be relied upon individually without the supporting text of remaining sections, appendices and plates. Our opinion and the success of the proposed construction will depend on following the report recommendations, good construction practices, and providing the necessary construction monitoring, testing and consultation to verify that work has been constructed as recommended. We recommend STRATA be retained to provide monitoring, testing, and consultation services to verify our report recommendations are being followed. We appreciate the opportunity to work with BHH Investments 1, LLC. We look forward to our continued involvement on this project throughout construction. Please do not hesitate to contact us if you have any questions or comments. Sincerely, ��t`J�\rENSF� STRATA;cc . 14253 Ic a IWoodworth, P.E.�OT�rFOFin ( Engineering Manager 9�q,,. __.� AM/MGW/am Adrian Mascorro, P.E. Project Engineer 8653 West Plackamore Drive, Boise, Idaho 83709 Phone.208.376.8200 rax.208.376.8201 www.stratageotech.com REPORT Limited Geotechnical Engineering Evaluation Southern Highlands Subdivision East Taconic Drive Meridian, Idaho Prepared For: Mr. Chad Hamel BHH Investments 1, LLC 1025 S. Bridgeway Place, Suite 290 Eagle, Idaho 83616 BOISE HUNTER HOMES Prepared By: STRATA, Inc. 8653 W. Hackamore Drive Boise, Idaho 83709 P.208.376.8200 F.208.376.8201 May 27, 2014 TABLE OF CONTENTS INTRODUCTION.... ................ ........... -- ......... .............. -- ........... ................................ 1 PROJECT UNDERSTANDING.......................................................................................2 Existing Site Conditions..................................................................................................2 ProposedConstruction....................................................................................................2 SUBSURFACE EVALUATION PROCEDURES..............................................................3 SUBSURFACE CONDITIONS........................................................................................3 LABORATORYTESTING...............................................................................................4 GEOTECHNICAL OPINIONS AND RECOMMENDATIONS...........................................4 Geotechnical Constraints and Opportunities................................................................5 Earthwork.................................................................................................................... 5 FillRemoval..............................................................................................................5 Site an Subgrade Preparation....................................................................................5 StructuralFill............................................................................................................6 Table 1. Structural Fill Specifications and Allowable Use ............................................. 6 Excavation Characteristics....................................................................................... 6 Compaction..............................................................................................................7 Utility Trench Backfill .................................... .......... .................. — ............. ................ 8 Wet Weather/Soil Construction.................................................................................8 Geosynthetics........................................................................................................... 8 ExistingSlope..............................................................................................................8 Pavement Section Design............................................................................................ 9 General.................................................................................................................... 9 Trafficand Subgrade................................................................................................9 Table 3. Pavement Design Parameters.................................................:::...................9 Asphalt, Aggregate Base Course and Subbase Materials ....................................... 10 Pavement Section Thickness..................................................................................10 Table 4. Asphalt Pavement Design Section...............................................................11 Pavement Maintenance..........................................................................................11 SiteDrainage.............................................................................................................11 StormwaterDisposal..............................................................................................11 Seasonal High Groundwater...................................................................................11 Surface Water Management for Individual Lots......................................................12 GEOTECHNICAL DESIGN CONTINUITY.....................................................................12 EVALUATION LIMITATIONS........................................................................................13 Geotechnical Engineering Evaluation Southern Highlands Subdivision East Taconic Drive Meridian, Idaho INTRODUCTION STRATA, A Professional Services Corporation (STRATA) has performed our limited geotechnical engineering evaluation for the proposed residential development to be located north of East Taconic Drive in Meridian, Idaho. Our evaluation's purpose was to explore the subsurface soil conditions at the project site and to prepare geotechnical recommendations to assist project planning, design and construction. We accomplished our services referencing our authorized revised proposal dated March 18, 2014 and email correspondence dated March 28, 2014. To accomplish our evaluation, STRATA performed the following services: 1. Coordinated exploration with T -O Engineers and the local utility notification center to help reduce the potential for damage to existing utilities. 2. Observed the excavation of 11 exploratory test pits within the planned development area. Explorations extended 10 to 13.5 feet below existing site grades. Temporary standpipe groundwater monitoring piezometers were installed in 7 of the test pits excavated. Our field geologist visually described, classified and logged soil encountered referencing the Unified Soil Classification System (USCS). 3. Performed laboratory tests with reference to ASTM International (ASTM) procedures including Atterberg limits, in-situ moisture content, grain size evaluation, r -value and proctor testing. We utilized these laboratory results to help characterize engineering parameters and to correlate soil engineering characteristics used in our design. 4. Performed and engineering evaluation in order to provide geotechnical design and earthwork construction recommendations. We worked closely with you and T -O Engineers to coordinate necessary elements of design and construction into a specific discussion of the related soil and geologic conditions. Our engineering analyses provides geotechnical recommendations and opinions for: 3 Earthwork • Fill removal • Site and subgrade preparation • Structural fill • Excavation characteristics • Compaction • Utility trench backfill • Wet weather/soil construction • Geosynthetics 8653 West Hacka more Driv ' ,i- ".'M) N n 108,376.8200 Fax. 208.376.8201 www.stratageotech.com Southern Highlands Subdivision File: B014105A Page 2 #r Existing Slope Information 6 Pavement Section Design • Traffic and subgrade • Asphalt, aggregate base course and subbase materials • Pavement section thickness • Pavement maintenance 0 Site Drainage • Stormwater disposal • Seasonal high groundwater (estimated) • Surface water management for individual lots i Geotechnical Design Continuity • Groundwater monitoring • Plan and specification review • Geotechnical design confirmation • Construction observation and testing 5. Prepared and provided an electronic copy of our final report of geotechnical findings, opinions and recommendations, including exploration logs and an exploration location plan. Hard copies of the report are available upon request. PROJECT UNDERSTANDING Existing Site Conditions The proposed development is undeveloped and is currently being actively farmed. The site is bounded by subdivision development to the southwest, East Taconic Drive to the southeast, and farm land on all other sides. An irrigation canal and the Ten Mile Creek are located approximately 200 and 700 feet east, respectively, of the eastern site boundary. Proposed Construction We understand the approximate 79 -acre development will consist of residential lot construction with associated asphalt roads and utility infrastructure. We understand the proposed homes will most likely be constructed with shallow foundations and crawl spaces. We anticipate stormwater will be disposed of via seepage beds or other on-site infiltration facilities. Based on review of the grading plan provided by T -O Engineers, dated May 12, 2014, we anticipate substantial cut and fill will be required for the proposed development. Specifically, grading plans indicate up to approximately 19 feet of cut and up to approximately 12 feet of fill is planned. Graded slopes of 2 feet horizontal to 1 foot vertical (2HAV) are planned. www.stratageotech.com ©STRATA, ln-, . All Rights Reserved Southern Highlands Subdivision File: B014105A Page 3 SUBSURFACE EVALUATION PROCEDURES STRATA accomplished subsurface exploration on March 31, 2014 via 11 exploratory test pits extending 10 to 13.5 feet below existing ground surface. Standpipe piezometers were installed in 7 test pits for future groundwater monitoring. The approximate exploration locations are illustrated on Plate 1, Exploration Location Plan, which also delineates the proposed development. Test pit locations were established in the field by taping from existing site features. A professional geologist visually evaluated the soil encountered in each test pit and logged the soil profile referencing the USCS. We provide a brief USCS explanation in Appendix A to help interpret the terms on the test pit logs. We also provide individual test pit logs in Appendix A. The test pits were backfilled with the excavated material to the ground surface following the completion of the excavations. STRATA accomplished previous exploration at this site on August 7, 2006. We have included the locations of test pits previously excavated within the site area on Plate 1 for your reference. Test pit logs for this previous exploration are also included in Appendix C. SUBSURFACE CONDITIONS Topsoil rooting and vegetation was observed to a depth of approximately 6 inches below grade within the southwest portion of the site, where active farming was not occurring. Soil conditions encountered within the test pits generally consist of lean clay or silt overlying silty sand with cementation, overlying poorly -graded gravel with sand with depth. We provide more specific discussion of each soil unit encountered below: 16 Silty Sand with Gravel (Fill) — Within the southwest portion of the site, adjacent to the hillside, we observed silty sand with gravel fill to depths of 2 to 4 feet below ground. We described fill soil as brown, loose to medium dense, and moist. 6 Surficial Lean Clay/Silt with Sand — Throughout majority of the site we observed native surficial lean clay and/or silt with sand to depths of 1 to 5.5 feet below ground. We described surficial soil as brown, stiff to hard, and moist. Within TP -8 we observed a 1 - foot -thick layer of fat clay at 1 to 2 feet below ground. 6 Silty Sand with Cementation — Underlying fill or surficial soil, we observed silty sand with varying amounts of calcium carbonate cementation to depths of 5.5 to 11.5 feet below ground. We described silty sand as brown, medium dense to dense, and moist. Within TPA below surficial soil, we observed brown, dense and moist clayey sand to 10.5 feet. 16 Gravel with Sand and Cobbles/Sand with Silt and Gravel —Underlying cemented silty sand or clayey sand, we observed poorly -graded gravel with sand and cobbles or poorly- www.stratag eotech.com Southern Highlands Subdivision File: B014105A Page 4 graded sand with silt and gravel to test pit termination depths of 10 to 13.5 feet. We described these soils as light tan to brown, medium dense to very dense and moist. 6 Groundwater — We did not encounter groundwater within test pits to the depths explored, with the exception of TP -8 where we observed groundwater at 6 feet below ground at the time of exploration. We performed groundwater monitoring at the site on April 22, 2014 and observed groundwater within TP -8 at a depth of 5.5 feet. The remaining on-site piezometers were dry at the time of our monitoring. We anticipate the depth to groundwater in the eastern portion of the site could potentially fluctuate primarily as a function of irrigation in the area. Subsurface variations may exist between exploration locations and may not be apparent until construction. Test pits only allow us to observe a portion of the site subsurface conditions. Where such variations exist, they may impact opinions and recommendations presented in this report, as well as construction timing and costs. We provide a USCS classification summary and specific soil contacts and descriptions on test pit logs provided as Appendix A to this report. LABORATORY TESTING We returned soil samples collected in the field to our laboratory for further classification and testing and accomplished laboratory testing referencing ASTM procedures. We developed our laboratory testing program for this project primarily to evaluate subsurface characteristics and engineering properties. Specifically, we accomplished moisture content, minus No. 200 wash, Atterberg limits, R -value, and proctor testing. We present index laboratory test results on test pit logs in Appendix A and laboratory test results and graphs in Appendix B. We will retain soil samples for 90 days and discard after this time period unless we are notified to store the samples for an extended period of time. GEOTECHNICAL OPINIONS AND RECOMMENDATIONS We present the following geotechnical recommendations to assist preliminary planning, design and construction of the proposed Southern Highlands Subdivision in Meridian, Idaho as illustrated on Plate 1 attached to this report. This report provides specific earthwork and other geotechnical design criteria for the development which the civil design and construction teams must review to verify the applicability to the planned development. We base our recommendations on the results of our field evaluation, laboratory testing, our experience with similar soil conditions, and our understanding of the proposed construction. If design plans change or if the subsurface conditions encountered during construction vary from those www.stratageotech.com Southern Highlands Subdivision File: B014105A Page 5 observed during our field evaluation, we must be notified to review the report recommendations and make necessary revisions. Geotechnical Constraints and Opportunities We provide the following discussion of what we consider to be important geotechnical items which will impact the development. Potential Uncontrolled Fill: During test pit explorations we encountered uncontrolled fill within the southwestern portion of the site, adjacent to the existing slope. However, we anticipate potential undocumented fill may be encountered throughout farming areas, and may not be evident until earthwork construction is commenced. As such, we recommend we observe the subgrade conditions after site grading to confirm unsuitable soil removal and subgrade soil are consistent with the recommendations in this report. Our report specifically outlines our opinions and recommendations regarding these soil conditions and relies on geotechnical continuity, communication between project team members specific to risk and cost -based decisions, and good construction practices to achieve the desired project outcome. Earthwork Fill Removal 1. Any existing, non-native soil at the project site is considered undocumented fill that is not suitable to support future structures and flatwork. 2. Remove all non-native soil to sufficient depth to expose existing native soil. 3. We estimate approximately 6 to 12 inches of fill removal will be required, depending on the amount of topsoil thickness in farming areas. Site and Subgrade Preparation 1. Test pits have been marked in the field with labeled stakes and/or standpipe piezometers. The test pits should be located prior to any earthwork site grading and test pits which are located beneath paving, structural fill or building lot areas should be re - excavated and replaced with structural fill in accordance with the recommendations in this report. 2. Strip existing topsoil and vegetation. Topsoil and vegetation was noted to extend approximately 6 inches below existing grade. 3. Scarify existing subgrade to a depth of 8 inches and moisture condition to within 3 percent of optimum moisture. 4. Compact the native subgrade soil as defined in Table 2 below. 5. Place and compact structural fill, as necessary, to achieve final grades. 04 www.stratageotech.com Southern Highlands Subdivision File: B014105A Page 6 Structural Fill 1. All fill placed must be placed as structural fill. 2. Fill placed on existing slopes greater than 5HAV will require benching, as depicted on Plate 2, Benching Schematic. 3. Structural fill requirements described in Table 1 below, in general, correlate to Idaho State Public Works Construction (ISPWC) material specifications: Table 1. Structural Fill Specifications and Allowable Use Structural Fill Product • Allowable Use Material Specifications Sieve Size % Passing • Soil classified as GW, GP, GP -GM, GM, SW, SP, 6 Inch 100 General Structural Fill • General site grading SP -SM, SM, or ML according to the USCS. : Maximum particle size must be less than 6 inches. Soil consisting of inert earth materials with less than 3 percent organics or other deleterious substances wood, metal, plastic, waste, etc), Granular Structural Fill • General structural fill • Over -excavations • Pavement section granular subbase • Soil classified as GW, GP, GP -GM, according to the USCS, and meeting the gradation provided. • Soil meeting requirements stated in the latest edition of the Idaho Standard for Public Works Construction (ISPWC), Section 801—Aggregate Subbase 61nch 100 3 Inch 90-100 No. 4 30-60 No. 200 <10 • Soil may not contain particles larger than 1 inch in 1 Inch 100 % Inch 80-100 Utility Trench Bedding Utility trench • construction median diameter and must meet the required gradation. • Soil meeting requirements stated in the latest edition of the Idaho Standard for Public Works 3/8 Inch 20-70 No. 4 5-20 No. 8 0-5 Construction (ISPWC), Section 305— Pipe No. 200 0-3 Bedding. • Soil may not contain particles larger than 1 inch in 1 Inch 100 Aggregate Base Course • General structural fill median diameter and must meet the required gradation. % Inch 90-100 No. 4 40-65 • Granular structural fill • Soil meeting requirements stated in the latest • Pavement section edition of the Idaho Standard for Public Works No. 8 30-50 base course Construction (ISPWC), Section 802 — Aggregate No. 200 3-9 Base. • Soil classified as CL, CH, MH, OH, OL or PT may Unsatisfactory Soil not be used at the project site for structural fill. • No structural • Soil not maintaining moisture contents within 3 applications percent of optimum. • Landscaping per • Any soil containing more than 3 percent organics landscape engineer by weight or other deleterious substances (wood, metal, plastic, waste, etc is unsatisfactory soil. Excavation Characteristics 1. Site soil is expected to be excavatable using conventional excavation techniques and equipment. 2. Bedrock is not expected within the planned construction limits. 3. Temporarily excavate, slope, shore or brace excavations in accordance with Occupational Safety and Health Administration (OSHA) guidelines. Regulations outlined www.stratageotech.com 8 i 2,3 ". 11'�ic !all Rights 121se veJ Southern Highlands Subdivision File: B014105A Page 7 in OSHA provide temporary construction slope requirements for various soil types and slopes less than 20 feet tall. 4. Site soil is classified as Type C soil referencing OSHA, and must be temporarily sloped back at least 1.5H:1 V. 5. Construction vibrations, seepage, or surface loading can cause excavations to slough or cave and should be avoided. 6. Ultimately, the contractor is solely responsible for site safety and excavation configurations and maintaining OSHA approved personnel for excavation monitoring. 7. Plan excavations carefully, allowing water collection points and utilizing conventional sumps and pumps to remove nuisance water from runoff, seeps, springs or precipitation. 8. Coordinate construction activities and excavation backfilling as rapidly as possible following excavation to reduce the potential for subgrades to degrade under construction traffic. 9. Subgrades must be graded to aggressively direct surface water away from subgrades to avoid infiltration. 10. Maintain dewatering systems to facilitate good drainage during construction and reduced over -excavation. Compaction Backfill to support any structure, embankment or improvement must be compacted to structural fill requirements presented in Table 2 below. Table 2. Required Compaction and Products for Designated Project Areas 1. Fill placed outside any building or pavement envelope can be placed as non-structural fill (i.e. landscape fill) providing there are no structures (sidewalk, curbs, utilities, signs, etc.) or embankment planned directly above the landscape fill. Landscape fill compaction requirements also apply to stemwall or basement wall backfill that does not support overlying structures such as asphalt, slabs or other improvements free of no structures. 2. Structural fill products must be moisture conditioned to near optimum moisture content and placed in maximum 10 -inch -thick, loose lifts. 3. Structural fill shall be compacted in 8 to 10 -inch -thick, loose lifts providing compaction equipment weighs a minimum of 5 tons. If smaller or lighter compaction equipment is www.stratageotech.com Required Structural Compaction Project Area Fill Product Requirement (ASTM D1557 Structural Subgrades Existing Soil Subgrade 92% Within 10 feet of building structural or General or Granular 95% pavement footprints Structural Fill Utility Trench Backfill Below Pavements, Utility Trench Fill 95% Slabs, and Buildings All Other Fills (more than 10 feet outside General Structural Fill 92% the building) Landscape Areas Sloped Flatter than General Structural Fill 88% 5H:1 V 1. Fill placed outside any building or pavement envelope can be placed as non-structural fill (i.e. landscape fill) providing there are no structures (sidewalk, curbs, utilities, signs, etc.) or embankment planned directly above the landscape fill. Landscape fill compaction requirements also apply to stemwall or basement wall backfill that does not support overlying structures such as asphalt, slabs or other improvements free of no structures. 2. Structural fill products must be moisture conditioned to near optimum moisture content and placed in maximum 10 -inch -thick, loose lifts. 3. Structural fill shall be compacted in 8 to 10 -inch -thick, loose lifts providing compaction equipment weighs a minimum of 5 tons. If smaller or lighter compaction equipment is www.stratageotech.com Southern Highlands Subdivision File: BO14105A Page 8 provided, reduce the lift thickness to meet the compaction requirements presented herein. 4. The site soil is expected to be suitable for reuse as general structural fill providing it can meet the criteria presented in Table 1 above. We anticipate existing silt and silty sand soil will exhibit an average shrinkage factor of 20 percent to 22 percent, when placed as structural fill. Existing sand and gravel soil will likely exhibit shrinkage factors of 16 percent to 18 percent. The shrinkage factors above are applicable considering in-place (bank) conditions. Utility Trench Backfill 1. Remove all saturated, loose or disturbed soil from the bottom of the utility trenches prior to placing pipe bedding. 2. Accomplish bedding for pipes and utility trenches in accordance with ISPWC Specifications. 3. Backfill the remainder of utility trenches in accordance with the Structural Fill specification. Wet Weather/Soil Construction 1. Ideally, perform earthwork construction during dry weather conditions. 2. The site soil is susceptible to pumping or rutting from heavy loads such as rubber -tired equipment or vehicles any time of the year. 3. Complete earthwork by track -mounted equipment that reduces vehicular pressure applied to the soil if construction commences in wet areas or before soil can dry. 4. Depending on precipitation, runoff and perched groundwater conditions, the site soil will be over optimum moisture content. Contractor shall expect these conditions and be prepared to install runoff management facilities and to replace wet or disturbed soil with granular structural fill. 5. If significant soft/wet soil conditions are encountered, the use of a woven geotextile fabric may be necessary. These material requirements are presented in the Geosynthetics report section below. Geosynthetics 1. Where required, apply geosynthetics directly on approved subgrade, free of wrinkles and over -lapped at least 12 inches. 2. Woven geosynthetic fabrics for subgrade stabilization and soil improvements shall have the following minimum properties of 700 pounds (CBR Puncture, ASTM D6241) and 200 pounds (Grab Tensile Strength ASTM D4632). 3. STRATA must be consulted prior to using geosynthetics for subgrade stabilization. Existing and Proposed Slopes The existing slope located along the southwest portion of the site consists of previously placed structural fill associated with the adjacent development. STRATA provided construction monitoring and testing services during the construction of this slope. Any excavation planned along or adjacent to the slope should not increase the slope to greater than a 2 horizontal to 1 www.stratageotech.com @ST;4\TA, All Rights Resorwed Southern Highlands Subdivision File: BO14105A Page 9 vertical (2HAV). This slope requirement is necessary to maintain slope stability for adjacent lots and to help with erosion control measures. Proposed cut and fill slopes planned for the development should be constructed at a maximum slope of 2HAV. Additionally, building setbacks for structures both above and below existing or constructed slopes must adhere to the 2012 International Building Code. STRATA can evaluate a possible reduction in slope setback distance on an individual basis, if desired. Any soil excavated along or adjacent to this slope area may be utilized as project structural fill, provided it meets the requirements as stated in the Structural Fill section of this report. Pavement Section Design General The following flexible asphalt pavement section design is provided referencing the Idaho Transportation Department (ITD) Gravel Equivalent Design Method using Ada County Highway District substitution ratios. STRATA estimated traffic loading and design parameters based on our proposed construction understanding and our understanding of the subsurface conditions. Traffic and Subgrade The following tables present our traffic loading, geotechnical design parameters and references, as well as the resulting flexible pavement section design recommendations. Table 3. Pavement Design Parameters Design Parameter Value Used References 33,000 ESALs Traffic Loading (Local Road, TI=6) Ada County Highway District 375,000 ESALs Standard (Collector Road, TI=B) Design Life 20 years Assumed Subgrade R -value 20 Based on R -value correlations see para raph below) Asphalt Layer Substitution Ratio 1.95 Ada County Highway District Standard Base Course Substitution Ratio 1.1 Ada County Highway District Standard Subbase Course Substitution Ratio 1.0 Ada County Highway District Standard 'Equivalent Single Axle Loads (ESALs). 14 www.stratageotech.com Southern Highlands Subdivision File: BO14105A Page 10 Laboratory testing of lean clay with sand resulted in an R -value of 33. However, based on the variability of surficial fine grained soil, and our experience with previous R -value testing for East Taconic Drive, we recommend an R -value of 20 be utilized for pavement section design. To help improve subgrade characteristics, the pavement subgrade should be prepared as recommended in this report's Site Preparation section. Subgrades must be shaped (crowned) and graded to facilitate positive drainage and inverted crowns must be avoided. Asphalt, Aggregate Base Course and Subbase Materials Crushed aggregate base course and granular subbase shall conform to the Structural Fill requirements and be placed directly over a properly prepared subgrade. A non -woven geotextile should be used for constructability during wet and inclement weather and to increase performance at the subgrade. The non -woven geotextile should have material properties and be placed as outlined in this report's Geosynthetics section. We recommend STRATA observe final subgrade preparations, geotextile placement and all aggregate placements. Asphalt concrete must be compacted to 92 percent of the maximum density for a Hveem or Superpave mix design. The final traveling surface of asphalt concrete shall meet ISPWC %- inch asphalt mix design requirements. Asphalt mix designs and all appropriate aggregate source certificates should be accepted by STRATA at least 5 days prior to initiating asphalt paving. Asphalt construction and final surface smoothness, joints and density should meet ISPWC specifications. If subgrade conditions appear significantly different during construction, traffic loading conditions change or traffic volumes increase, STRATA should be notified to amend our design accordingly. Pavement Section Thickness STRATA evaluated the pavement sections utilizing the ITD pavement design methodology, soil -engineering parameters from previous field and laboratory testing and the estimated traffic -loading conditions. Based on subgrades prepared as recommended and the traffic criteria provided, Table 4 provides the recommended asphalt section for the anticipated pavement application. If traffic loading or subgrade conditions change as design is finalized or during construction, STRATA must review our pavement analyses and resulting sections. 04 www.stratageotech.com Southern Highlands Subdivision File: BO14105A Page 11 Table 4. Asphalt Pavement Design Section Pavement Maintenance We recommend crack maintenance be accomplished on all pavement surfaces every 3 to 5 years to reduce the potential for surface water infiltration into the underlying pavement subgrade. Surface and subgrade drainage are extremely important to the performance of the pavement section. Therefore, we recommend the subgrade, base and asphalt surfaces slope at no less than 2 percent to an appropriate stormwater disposal system or other appropriate location that does not impact adjacent buildings or properties. The pavement's lifespan is dependent on achieving adequate drainage throughout the section, especially at the subgrade elevation. Ponding water at the pavement subgrade surface can induce heaving during the freeze -thaw process. Site Drainage Stormwater Disposal We recommend all subsurface infiltration facilities extend a minimum of 12 inches into poorly -graded gravel with sand. Based on our test pit explorations, we anticipate excavation depths of 5.5 to 11 feet will be required to expose gravel with sand. Stormwater facilities constructed into gravel with sand may be designed utilizing the following allowable infiltration rate: 40 Allowable infiltration rate (gravel with sand) = 12 inches per hour Seasonal High Groundwater As stated previously, groundwater on April 22, 2014 was encountered at 5.5 feet within the northeast portion of the site (TP -8). Subsequent groundwater monitoring in May 2014 identified groundwater in TP -8 at a depth of 5.1 feet and in TP -10 at 7.9 feet. Groundwater levels are typically at the peak for the season during the late summer irrigation season. Based on our experience in the area, we anticipate seasonal high groundwater level near the eastern portion of the site (near TP -8 and TP -10), will occur at a depth of approximately 4.5 feet below existing grade. Additionally, based on previous monitoring, groundwater in the northern portion www.stratageotech.com ()STRATA, Inc. Ali ;Rights F?a e vvtl Asphalt Aggregate Granular Asphalt Pavement Application Concrete Base Subbase (inches) (inches) (inches) Local Roads & Access Drives (TI = 6) 2.5 4.0 10.0 Collector Roads and Heavy Duty Access (TI = 8) 3.0 6.0 13.0 Pavement Maintenance We recommend crack maintenance be accomplished on all pavement surfaces every 3 to 5 years to reduce the potential for surface water infiltration into the underlying pavement subgrade. Surface and subgrade drainage are extremely important to the performance of the pavement section. Therefore, we recommend the subgrade, base and asphalt surfaces slope at no less than 2 percent to an appropriate stormwater disposal system or other appropriate location that does not impact adjacent buildings or properties. The pavement's lifespan is dependent on achieving adequate drainage throughout the section, especially at the subgrade elevation. Ponding water at the pavement subgrade surface can induce heaving during the freeze -thaw process. Site Drainage Stormwater Disposal We recommend all subsurface infiltration facilities extend a minimum of 12 inches into poorly -graded gravel with sand. Based on our test pit explorations, we anticipate excavation depths of 5.5 to 11 feet will be required to expose gravel with sand. Stormwater facilities constructed into gravel with sand may be designed utilizing the following allowable infiltration rate: 40 Allowable infiltration rate (gravel with sand) = 12 inches per hour Seasonal High Groundwater As stated previously, groundwater on April 22, 2014 was encountered at 5.5 feet within the northeast portion of the site (TP -8). Subsequent groundwater monitoring in May 2014 identified groundwater in TP -8 at a depth of 5.1 feet and in TP -10 at 7.9 feet. Groundwater levels are typically at the peak for the season during the late summer irrigation season. Based on our experience in the area, we anticipate seasonal high groundwater level near the eastern portion of the site (near TP -8 and TP -10), will occur at a depth of approximately 4.5 feet below existing grade. Additionally, based on previous monitoring, groundwater in the northern portion www.stratageotech.com ()STRATA, Inc. Ali ;Rights F?a e vvtl Southern Highlands Subdivision File: B014105A Page 12 of the property (near TP -4 and TP -5), may occur at depths as shallow as approximately 6 feet below grade. It is our opinion groundwater within the remainder of the site will occur at depth of 14 to 15 feet below existing site grades. However, groundwater monitoring must be accomplished during irrigation season, April to October, to confirm seasonal high groundwater levels for design. We accomplished groundwater monitoring at the time of our site exploration in 2006. We provide results of that groundwater monitoring in Appendix C, along with previous test pit exploration logs. Surface Water Management for Individual Lots Surface water associated with rain, snow and irrigation water can become perched above the relatively impermeable native and structural fill soils which presently exist and is planned beneath the proposed individual lots. Improper management of near -surface water, by not providing an effective grading and drainage design for each lot, can result in moisture or water entering the crawl spaces or basement areas of the residences. Possible sources of near -surface water include pressurized irrigation water, rainwater, snowmelt, or leaking water lines. These water sources can be transmitted to the foundation stem wall and pond beneath a structure via irrigation, roof downspout discharge, and snow melt. Possible conduits for water to enter into crawl spaces or basements can include loose or porous backfill placed adjacent to foundation walls and loose or porous backfill in utility trenches that extend through or beneath foundations. Considering the above discussion we recommend that consideration be given to the potential for surface water intrusion and be considered during planning, design, and construction of individual lots. Additionally, we recommend roof drains for individual residences be connected to the overall subdivision stormwater drainage system. GEOTECHNICAL DESIGN CONTINUITY Geotechnical design continuity will be an important aspect of this project's successful completion. In our opinion, geotechnical continuity can occur in 4 stages in the planning, design and construction project aspects. Specifically, we recommend STRATA maintain the geotechnical design continuity in the following aspects: 5 Groundwater Monitoring: The groundwater level should be monitored during the upcoming irrigation season to verify the seasonal high groundwater level beneath the site. Piezometers were installed to monitor groundwater levels. Monitoring typically www.stratagootech.com Southern Highlands Subdivision File: B014105A Page 13 should be accomplished on a monthly basis between April and October. STRATA remains available to perform groundwater monitoring at your request. 0 Plan and Specification Review: We recommend STRATA be retained to review final design and construction plans and specifications to verify our geotechnical recommendations are incorporated into project bidding and construction documents as well as to provide additional recommendations based on the final design concepts. These efforts can help provide document continuity across the engineering disciplines and reduce the potential for errors as the project concepts evolve. i Geotechnical Design Confirmation: The information contained in this report is based on preliminary development plans. The grading elevation as well as site geometry can significantly alter our opinions and design recommendations. Specifically, changes in the soil cut and fill geometry may require additional analyses specific to the actual anticipated construction conditions. Therefore, it is critical STRATA provide geotechnical continuity through final planning and design for the planned construction as individual aspects become available during design development phases of the project. It has been our experience that having consultants from the design team review the construction documents prior to bidding helps reduce the potential for errors, and also reduces costly changes to the contract during construction. If we are not provided such opportunities, we cannot be responsible for soil -related design or construction -related errors, omissions, delays or increased costs that are identified during construction. 'Ti Construction Observation and Testing: We recommend STRATA be retained to provide construction monitoring to verify the soil conditions and that report recommendations are incorporated into the actual construction. Such observation is an important part of the geotechnical design process and can help reduce the potential for soil engineering- or construction -related errors or omissions. For this project it is especially important to maintain this geotechnical continuity during uncontrolled fill identification, removal and replacement as well as during the subgrading process. If we are not retained to provide the recommended plan review and construction monitoring services, we cannot be responsible for soil engineering - related construction errors or omissions. Further, the selected firm must be required to document in writing to the design team and BHH Investments 1, LLC that they have read and will implement this report and its recommendations in their entirety as the geotechnical engineer of record. EVALUATION LIMITATIONS This report has been prepared to assist project planning design and construction of the proposed Southern Highlands Subdivision to be located north of East Taconic Drive in Meridian, Idaho. Our geotechnical findings and opinions have been developed based on the authorized subsurface exploration and laboratory testing, as well as our understanding of the project at this time. Our geotechnical design recommendations are specific to the planned design and infrastructure construction and should not be extrapolated to other future site developments without allowing adequate geotechnical consultation by STRATA. STRATA's scope provides recommendations for infrastructure construction, which does NOT include recommendations for www.stratageotech.com Southern Highlands Subdivision File: B014105A Page 14 individual residential lots or residential structures, and STRATA does NOT assume the role of geotechnical engineer of record for individual residential lot construction. Our services consist of professional opinions and findings made in accordance with generally accepted geotechnical engineering principles and practices in southwest Idaho at the time of this report. The geotechnical recommendations provided herein are based on the premise that appropriate geotechnical consultation during subsequent design phases is implemented and an adequate program of tests and observations will be conducted by STRATA during construction to verify compliance with our recommendations and to confirm conditions between exploration locations. This acknowledgment is in lieu of all warranties either express or implied. The following plate and appendix accompany and complete this report: Plate 1: Exploration Location Plan Plate 2: Benching Schematic Appendix A: Unified Soil Classification System (USCS) & Exploratory Test Pit Logs Appendix B: Laboratory Test Results Appendix C: 2006 Test Pit Logs and Groundwater Monitoring 04 www.stratageotech.com Fa-❑ 1 1 n n m ZLL � � 1 mm S �1 I yy \V ,ate,ai �1 1 ,In SAll .lel 1 ,wl Q t ♦\ 69�y N'' '& 1 A > s in x�l aw 9f P Reql I $to m to R F. \♦\;\` ♦`\s` -moo g Ia C JIL 9 a�.6�,} R �al Rol B ,�"� .e9z 1 f8 --IS Al 91 S I 1 .wl y m �:r R,IIrm3 I m R m.19 1 Rla In na g 19 `. 1.9 Ins fs gl ��� I I .RI � $ ♦ \ ,LI a l _ / � N g y1 nq � � 1 'YI, s � •a1 � . g /I� s '� 'c 0 ♦��a •' 4, Qui 6^x'0 �/� �,� ..91 ��t w� InY d 7C \ \9`\ ♦ oq yip � y '4}\; .a m (//S, a,' d .`a' / 1 f� � ''W �$ ~ A ♦♦\\\b 3 07 Q -� \\\♦ ' foi /d/ \+\4 ♦ M� 'Qi � �a � /� n� I p '6 +} p ♦\ �t �' d 4 \ � � r 2 / / F A9 Ell 5 dUJ 1 1 n n m ZLL � � 1 mm S �1 I yy \V ,ate,ai �1 1 ,In SAll .lel 1 ,wl Q t ♦\ 69�y N'' '& 1 A > s in x�l aw 9f P Reql I $to m to R F. \♦\;\` ♦`\s` -moo g Ia C JIL 9 a�.6�,} R �al Rol B ,�"� .e9z 1 f8 --IS Al 91 S I 1 .wl y m �:r R,IIrm3 I m R m.19 1 Rla In na g 19 `. 1.9 Ins fs gl ��� I I .RI � $ ♦ \ ,LI a l _ / � N g y1 nq � � 1 'YI, s � •a1 � . g /I� s '� 'c 0 ♦��a •' 4, Qui 6^x'0 �/� �,� ..91 ��t w� InY d 7C \ \9`\ ♦ oq yip � y '4}\; .a m (//S, a,' d .`a' / 1 f� � ''W �$ ~ A ♦♦\\\b 3 07 Q -� \\\♦ ' foi /d/ \+\4 ♦ M� 'Qi � �a � /� n� I p '6 +} p ♦\ �t �' d 4 \ � � r 2 / / F A9 Ell COMPACTED FILL (SEE NOTES) FILL SURFACE BENCHES: 6FEET WIDE (MINIMUM) NOTES: 1. BACKFILL TO BE PLACED IN 8 -INCH, LOOSE LIFTS AND COMPACTED TO A MINIMUM OF 95% OF THE MAXIMUM DRY DENSITY AS DETERMINED BY ASTM D 1557. FILL SHOULD CONSIST OF APPROVED, ON-SITE SOIL OR STRUCTURAL FILL. 2. BENCHES MAXIMUM OF 4 FEET VERTICAL. N- )k'ldJIOVHL ONI" (NGl 'U SC=LL) FA1»��I�]I I_1 UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GRAPH SYMBOL LETTER SYMBOL TYPICAL NAMES BG Baggie Sample California Modified 3—Inch OD Split—Spoon Sample GW Well—Graded Gravel, BK Bulk Sample CLEAN Core 0 Gravel—Sand Mixtures. RG Ring Sample GRAVELS—Graded Q GP PoorlyGravel, .°• . Gravel—Sand Mixtures. GRAVELS Silty Gravel, Gravel— GRAVELS GM Sand—Silt Mixtures. WITH Clayey Gravel, Gravel— COARSE FINES GC Sand—Clay Mixtures. GRAINED Well—Graded Sand, SOILS CLEAN SW Gravelly Sand. SANDS Poorly—Graded Sand, SP Gravelly Sand. SANDS • • ; Silty Sand, SW THS • • • • SM Sand—Silt Mixtures. FINES •• • .� . SC Clayey Sand, Sand—Clay Mixtures. Inorganic Silt, Sandy ML or Clayey Silt. SILTS AND CLAYS Inorganic Clay of Low CL to Medium Plasticity, LIQUID LIMIT Sandy or Silty Clay. LESS THAN 50% Organic Silt and Clay OL of Low Plasticity. FINE GRAINED Inorganic Silt, Mica— SOILS MH ceous Silt, Plastic Silt. SILTS AND CLAYS Inorganic Clay of High CH Plasticity, Fat Clay. LIQUID LIMIT GREATER THAN 50% OH Organic Clay of Medium \ . to High Plasticity. Peat, Muck and Other PT Highly Organic Soils. BORING LOG SYMBOLS GROUNDWATER SYMBOLS TEST PIT LOG SYMBOLS IStandard 2—Inch OD Split—Spoon Sample - Groundwater After 24 Hours BG Baggie Sample California Modified 3—Inch OD Split—Spoon Sample (7-3-07) Indicates Date of Reading BK Bulk Sample IIRock Core 0 Groundwater RG Ring Sample Shelby Tube 3—Inch OD at Time of Drilling Undisturbed Sample Shorthand Notation: BGS = Below Existing Ground Surface N.E. = None Encountered 2' Remarks USCS Description �?�m E,o W o� �—�E Note: BGS =Below o mEr m aom z o 2. � g i Ground Surface LL PI 0 LEAN CLAY, (native), (CL) brown, very stiff, moist Trace vegetation and organics CL to about 6 inches BGS. BG 3.5 Strong cementation (caliche) SILTY SAND, (SM) light brown, dense, moist • from 1 to 4 feet BGS BG 20.3 z.s 5.0 SM Moderate cementation • (caliche) from 5 to 9 feet BGS • 7.5 POORLY GRADED SAND WITH SILT AND GRAVEL, (SP -SM) brown, dense, moist 0.0 SP- BK 8.0 SM I 12.5 Test Pit Terminated at 13.0 Feet. Client: BHH INVESTMENTS 1, LLC. Test Pit Number: TP -1 EXPLORATORY Project: B014105A Date Excavated: 03-31-2014 sTr2a-ra TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' A Nx...r,uxni 5eavmss co..oan,;ou `"�""`E'"�""p°r Depth to Groundwater: N.E. Logged By: SW"'Y Sheet 1 Of 1 m ON Remarks USCS Description ❑ c6 E aoN oi.~_ Nv' Note: BGS =Belowo D z a o 2� a ¢ Ground Surface 0 LL PI SILTY SAND WITH GRAVEL, (fill), (SM) brown, loose, moist Trace vegetation and organics • to about 6 inches BGS. SM • SILTY SAND, (native), (SM) light tan, dense, moist 2.5 Moderate cementation (caliche) from 2 to 5.5 feet BGS. SM 5.0 POORLY GRADED SAND WITH SILT, And Cobble And Gravel, (SP -SM) light tan, very dense, moist zs BK SP- ' SM 10.0 12.5 Test Pit Terminated at 13.0 Feet. Client: BHH INVESTMENTS 1, LLC. Test Pit Number: TP -2 EXPLORATORY Project: B014105A Date Excavated: 03-31-2014 sTRaTa TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' AN.a.,—,Su—,. I'-1 ""oind°r Depth to Groundwater: N. E. Logged By: SW Sheet 1 Of 1 21 Remarks Description E E o Note: BGS =Below❑ ro z❑ o U o ¢ Ground Surface anUSCS LL PI o.o SILTY SAND WITH GRAVEL, And Cobbles (fill), (SM) brown, medium dense, moist ' Moderate vegetation and • organics to about 6 inches • BGS. ' BG SM 2.5 Grass roots observed from 3.5 • to 4 feet BGS SILTY SAND, (native), (SM) light brown, dense, moist 5.0 SM Moderate cementation ' (caliche) from 5 to 6 feet BGS SILTY SAND, (SM) tan, very dense, moist 7.5 BK 20.0 � SM 0.0 Test Pit Terminated at 12.0 Feet, Client: B}H INVESTMENTS 1, LLC. Test Pit Number: TP -3 EXPLORATORY Project: B014105A Date Excavated: 0331-2014 sTRaTa TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' APwo... C ....... Depth to Groundwater: N.E. Logged By: SW Shoot 1 Of 1 USCS Description E E ro E a mo m m �;, o 2 o m m N m e E Remarks ❑ r ror Goin a o- �— �� Note: BGS =Below ❑ c' m ° Z o a a Ground Surface LL PI 0 LEAN CLAY, With Sand (native), (CL) brown, stiff to hard, moist BG 1.0 BG 4.0 CL 2.5 CLAYEY SAND,. With Gravel, (SC) brown, medium dense, moist ' • BG s.0 • • • • Light cementation from 6 to 10 • • feet BGS SC •.•. 7.5 ' 0.0 SILTY SAND, (SM) brown, medium dense, moist Light calcium carbonate SM 12'5 • Piezometer installed to 13 feet 1 1 113GS Test Pit Terminated at 13.0 Feet. Client: BHH INVESTMENTS 1, LLC. Test Pit Number: TP -4 EXPLORATORY Project: B014105A Date Excavated: 03-31-2014 sTRaTa TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' A Pxorrtsrorvat Srav¢es Coevoammu sM-9,,.,.` ""`P""ind"'' Depth to Groundwater: N.E. Logged By: SW Sheet 1 Of 1 USCS Description m K y a E N am En mo 'yom .? c� m 0 2 o w m d2' v v.E Remarks ❑ a r m 62 a o -- �-- Note: BGS = Below Z a Ground Surface 0 LL PI SILT, (native), (ML) brown, firm, moist 0.5 ML 1.0 LEAN CLAY WITH SAND, (CL) brown, stiff, moist CIL BK 2.0 33 11 SILTY SAND, (SM) brown, dense, moist 2.5 • Moderate cementation (caliche) from 3 to 4 feet BGS. • Strong cementation (caliche) • from 4 to 5 feet BGS 5.0 SM • • 7.5 POORLY GRADED GRAVEL WITH SAND, ' (GP) tan brown, dense, moist o p?; BG 2.3 a fl. 0.0 ; ne. o..�: aQn GP O'• off•. Gp, 12.5 o p:. �• Piezometer installed to 13 feet BGS. Test Pit Terminated at 13.0 Feet. Client: BHH INVESTMENTS 1,. LLC. Test Pit Number: TP -5 EXPLORATORY Project: B014105A Date Excavated: 03-31-2014 STRaTa TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' n Na I"`9"''"` "`'"mound"P Depth to Groundwater: N. E. Logged By: SW Sheet 1 Of 1 USCS Description d E E a mo a d .N o- 2 o N a`, d o, E Remarks P ❑ ? a z in o Y — ;u Note: BGS =Below ❑ °a Ground Surface LL PI 0.0 SILT, (native), (ML) brown, firm, moist ML CL BG BG 0.5 LEAN CLAY WITH SAND, (CL) brown, stiff, 1.0 moist SILTY SAND, (SM) brown., medium dense to dense, moist 2.5 • Moderate cementation • (caliche) from 3 to 12 feet BGS 5.0 SM 7.5 • BG • 10.0 POORLY GRADED GRAVEL, With Sand, (GP) brown, dense, wet z.s GP n Q° o•l}: Test Pit Terminated at 13.5 Feet. Client: BHH INVESTMENTS 1, LLC. Test Pit Number: TP -6 -EXPLORATORY Project: B014105A Date Excavated: 03-31-2014 !SYRa-ra TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' APxofea.,a„u sw.:y"`''""'"`wauyd°P Depth to Groundwater: N. E. Logged By: SW Sheet 1 Of i USCS Description v= P E E a m o a an d m a E Remarks o u w a d 'o p — Note: BGS = Below N ^ Z r o :5° v ° a ¢ Ground Surface 0.0 LL PI LEAN CLAY, (native), (CL) brown, very stiff, moist CL 2.5 BG Strong cementation (caliche) SILTY SAND, (SM). brown, medium dense to dense, moist from 1 to 6 feet BGS BK 28.0 • 2.s SM 5.0 POORLY GRADED GRAVEL WITH SAND, And Cobbles, (GP) brown, moist VQt. Q Q D Q° o..�. 7.5 a.• a pn• o bl'YA. ° ('S° BG GP o D: 10.0 ;�°• D Q.-b% n Qy,. o a�. 12'5 o'p Piezometer installed to 13 feet BGS. Test Pit Terminated at 13.0 Feet. Client: BHH INVESTMENTS 1, LLC. Test Pit Number: TP -7 EXPLORATORY Project: B014105A Date Excavated: 03-31-2014 STRaTa TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' AP ....... o„„s.wv,<., coaooa<,oH �`�"' '""`"`""""O"P Depth to Groundwater: N. E. Logged By: SW Sheet 1 Of 1 Test Pit Number: TP -8 EXPLORATORY Remarks USCS Description U L sTRa-ra A P..... ,oxn, seamces c.wow„�„ TEST PIT LOG a - Note: BGS=Below Depth to Groundwater: 6:' n ?5 Sheet 1 Of 1 m�z 0 2. U oa o- ¢`m1 Ground Surface 0 LL PI LEAN CLAY, (native), (CL) brown, stiff, moist CL 1.0 BG 1.5 FAT CLAY, (CH) brown, stiff, moist CH No Is 90.0 29.1 52 34 SILTY SAND, (SM) brown, medium dense to dense, moist 2.5 POORLY GRADED GRAVEL WITH SAND, And Cobbles, (GP) brown, dense, saturated 5.0 7.5 r j Moderate cementation SM IL IT . pmroIQche) from 3.5 to 6 feet GP � ° U o D: • Piezometer installed to 10 feet Test Pit Terminated at 10.0 Feet. 10.D �- BGS. Client: BHH INVESTMENTS 1, LLC. Test Pit Number: TP -8 EXPLORATORY Project: B014105A Date Excavated: 03-31-2014 L sTRa-ra A P..... ,oxn, seamces c.wow„�„ TEST PIT LOG x Backhoe: CASE 580 Bucket Width: 2' Depth to Groundwater: 6:' n Logged By: SW Sheet 1 Of 1 V o �, ad Eo;; o5 m `m m Remarks USCS Description P ° H .v E E 0 0 9 o a so 0 W 8.E Note: BGS =Below azm o o— u ¢� Ground Surface 0 LL PI SILT, (native), (ML) brown, stiff, moist ML BG 1.0 LEAN CLAY, (CL) brown, stiff, moist BG 1.5 CIL BK RG 2.5 SILTY SAND, (SM) light brown, very dense, moist • Strong cementation (caliche) • from 4 to 6.5 feet BGS SM 5.0 POORLY GRADED GRAVEL W ITH SAND, And Cobbles, (GP) brown, dense, moist P Q' 7.5 nQ°. ;p°•. BG d b. °� GP 10.0 •O: o o p°. o '�'• Piezometer installed to 12 feet I JBGS- Test Pit Terminated at 12.0 Feet. i Client: BHH INVESTMENTS 1, LLC. Test Pit Number: TP -9 EXPLORATORY Project: B014105A Date Excavated: 03-31-2014 sTRaTa TEST PIT LOG i Backhoe: CASE 580 Bucket Width: 2' s"��""' "`"�"`E'"�""d 0r Depth to Groundwater: N. E. Logged By: SW Sheet 1 Of 1 s 41m a am m com c, o m� ns.N `m '3 Remarks USCS Description E r= Nr 2 ce.E Note: BGS =Below Mz o �� a ¢ Ground Surface 0.0 LL PI SILT WITH SAND, (ML) brown, stiff to hard, moist 1.0 BG 78.0 23.1 >4.5 No cementation in silt 2.5 ML >4.5 >4.5 5.0 POORLY GRADED GRAVEL WITH SAND, And Cobbles, (GP) brown, dense, moist v O• yQ. 7.5 0 P11.D, oVD: GP �. d' 10.0 o Q° pQa,. o D', °C o "D . Q. 12'5 ° O Piezometer installed to 13 feet p D:. BGS. Test Pit Terminated at 13.0 Feet. Client: BHH INVESTMENTS 1, LLC. Test Pit Number: TP -10 EXPLORATORY Project: B014105A Date Excavated: 03-31-2014 s-rr�aTa TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' AFxores„o„_„5—,caao.,,,o� s"�"''`"'"``�"""'d°P Depth to Groundwater: N.E. Logged By: SW Sheet 1 Of 1 Remarks USCS Description ❑ j � 6 z -2 E Note: BGS = Below ❑ o�0, U a ¢ Ground Surface LL PI 0,0 LEAN CLAY, (CL) brown, firm to stiff, moist BG 1.0 CIL BG 24.2 2.0 35 16 2.5 SILTY SAND, With Sand, (SM) brown, medium dense to dense, moist • • Moderate cementation (caliche) observed from 4 to 6 feet BGS. 5.0 SM • • • • ' POORLY GRADED GRAVEL WITH SAND, (GP) brown, dense, moist T5 Q ' GP W c'p 1a.o q• lfl• b Piezometer installed to 12 feet BGS. Test Pit Terminated at 12.0 Feet. Client: BHH INVESTMENTS 1, LLC. Test Pit Number: TP -11 EXPLORATORY Project: 6014105A I Date Excavated: 03-31-2014 sTRaTa TEST PIT LOG Backhoe: CASE 580 Bucket Width: 2' ANo.... o„., 5,o..., s"`�""'` "`4`�""d°p Depth to Groundwater: N.E. Logged By: SW Sheet 1 Of 1 APPENDIX B U N O �e� wVi C J S J Q � m S U U v U W U U- U CCW `\11L Q m E d uj w v M ccO CL Q `1 U N O �e� wVi C J S J m U U U U- U m E d v M J N 9 Q J M to M CP o C O .N O N 0 O C'4 M N CO N O O O m O Z 0 Y M r N (%% c m O N Ci N M N d' N O U C � L >O x N m a + C (D C m � O a U) m O 0 `m 3U)ULU m m U m U) m E_ y> m m m.3 m p U) (D c m U) U) d J b d Qo mU� W LL(�2— C M O J E Z O m L Ln OD n N N N N N i W Ln Ln 11') In p F- m a m C7 a m GRADATION ANALYSIS ASTM D 1140 Project: Southern Highlands Development Client: BHH Investments Project Number: B014105A Lab Number: B01400230B Sample Identification: TP -1 @ 10-11 ft Sample Classification: P. G. Sand with Silt and Gravel Date tested: 4/8/14 By: J Sanders Fine iu Gravel Sand s 0 (J Coarse Fine Coarse Inches Screen Sizes o 0 90 $ 80 70 p W t� 60 5 a F 50 w v w 40 4 CL 0z 30 20 1 10 8 0 100 10 1 0.1 SOIL GRAIN DIAMETER, millimeters s T R aT a Reviewed by: "—Y6�� A AROFESSIONAI SERVICES CORPORATION fh�i'C9r,4'y F/om 4-A, �' ,owN d Ur Medium Fine GRADATION ANALYSIS ASTM D 1140 Project: Southern Highlands Development Client: BHH Investments Project Number: B014105A Lab Number: B01400230B Sample Identification: TP -1 @ 10-11 ft Coarse Sample Classification: P. G. Sand with Silt and Gravel Coarse Date tested: 4/8/14 By: J Sanders Fine Gravel Sand Inches Screen Sizes O O QD N unV M - M M # # # # # 100 # # # # # 90 8 80 115 70 6 z 60 5 a h 50 z LU c� w 40 4 a 30 20 1 10 8 0-1E -L - - 100 10 1 0.1 SOIL GRAIN DIAMETER, millimeters 00 �J Reviewed by: A PROFESSIONAL SERVICES CORKM -... _T.L7<�r/I-y FrowL F-h<f7rnuh.+1-� a 0 (J Coarse Fine Coarse Medium Fine MOISTURE -DENSITY RELATIONSHIP CURVE ASTM D 1557 Method B Project: Southern Highlands Development Client: BHH Investments, LLC Project Number: B014105A Sample Number: B01400230B Sample Identification: TP -1 @ 10-11 ft Sample Classification: P. G. Sand with Silt and Gravel Date Tested: 4/2/14 By: K Barnett Soil Tempered: No Rammer Type: Manual 125 W11 115 U x;110 r F z z LU 0 y105 0 Will 95 90 11 Maximum Dry Density, pcf : 106.7 GRADING ANALYSIS SCREEN SIZE %PASSING AS TESTED 6 inch 3 inch 2 inch 100 3/4 inch 3/8 inch 87 100 #4 screen Corrected Dry Density, pcf: 111.3 Corrected Moisture Content, W 14.3 12 13 14 15 16 17 MOISTURE % Reviewed By: '/ 18 19 20 21 22 04 SYRaTa A PROFESSIONAL SERVICES CORPORATION yKJ' _g)r,4y Arom 4 -*6 E. IvouKC Vp GRADATION ANALYSIS ASTM D 1140 Project: Southern Highlands Development Client: BHH Investments Project Number: B014105A Lab Number: B01400230C Sample Identification: TP -3 @ 8 - 9 ft Coarse Sample Classification: Silty Sand Coarse Date tested: 4/9/14 By: J Sanders Fine a Gravel Sand 0 C) Inches Screen Sizes a0 # o 0 10o rn V ail N M M 3k ik ik ik ik 9 90 80 70 60 a F 50 z w U w 40 a 30 20 10 0 100 10 1 0.1 SOIL GRAIN DIAMETER, millimeters Reviewed by: A PROFESSIONAL SEHn �RPORAFION SNt<�rr Yy From Jhr c]rovrt0 Vr Coarse Fine. Coarse Medium Fine R-VALUE Percolation: None Idaho T 8 P°int2 Project: Southern Highlands Development Exudation, PSI Project No: B014105A Client: BHH Investments 349 Lab Number: B01400230D Sample Identification: TP-5 @ 1.5 - 2 ft 98.5 Date Received: 3/31/14 Sample Classification: Lean Clay with Sand 22.2 Date Tested: 4/8/14 By: J Sanders 19.6 Exp. Pressure, PSI SOIL CONSTANTS 0.00 0.89 100 1/2" R VALUE: 33 3I8" No. 4 No. e No. 16 o $ v m No. 100 No. 200 i � O 0 0 M � Q V3 Lqo a m 0 m 0 N o p d d N d c 0 c 0 N c m x W � x v W 0 0 0 o � N O O O W r t00 N m N o O R value Note: This report covers only material as represented by this sample and does not necessarily cover all soil from this layer or source. STFRaTa �W A PROFESSIONAL SERVICES CQHJ10nA11oN Reviewed by: ZH-FG�ri:l`y Frnwt hh< C�/r nuKd U� R VALUE DATA Percolation: None Pointl P°int2 P°int3 Exudation, PSI 123 160 349 Dry Density, PCF 96.9 98.5 99.6 Moisture Content, % 22.2 21.0 19.6 Exp. Pressure, PSI 0.00 0.00 0.89 GRADATION: AASHTO T-11, T27 ❑1" SCREEN AS RECEIVED AS TESTED SIZE %PASSING %PASSING 4" 3" 2" 3/4" 100 100 1/2" 3I8" No. 4 No. e No. 16 No. 30 No. 50 No. 100 No. 200 i APPENDIX C Sandy SILT — tan, very stiff, ML slightly moist. c REMARKS S N USCS Description w N N 5 J O W J N � •- O j Backhoe: CASE 580 SUPER C �� o a � O rte+ Logged By: BN g Note: BGS = Below Ground E Surface U a Lean CLAY (Native) — brown, CL Moderate vegetation stiff to very stiff, moist. and organics observed 1 1.5-2 to 6 inches BGS. Sandy SILT — tan, very stiff, ML slightly moist. 3 Client: Test Pit Number: TP -4 EXPLORATORY � TEST PIT LOG S T FR a•I� RRRa c,o,—w.— xn.« 'G^"9"'rFa""^`�"'"^`'"+` Sheet oft Silty SAND — tan, dense, SM Date Excavated: 8-7-2006 Backhoe: CASE 580 SUPER moist. 4 -6-28-06) • Logged By: BN Poorly—Graded GRAVEL with V GP Sand — tan, dense, moist to saturated. �. 6 � Test pit terminated at 8 feet BGS due to caving conditions. 7 E 10 11 12 13 14 2-2.5 Standpipe piezometer installed to 8 feet BGS. 15 Client: Test Pit Number: TP -4 EXPLORATORY � TEST PIT LOG S T FR a•I� RRRa c,o,—w.— xn.« 'G^"9"'rFa""^`�"'"^`'"+` Sheet oft Project: B06167A Date Excavated: 8-7-2006 Backhoe: CASE 580 SUPER Bucket Width: 2' Depth to Groundwater: 4.3' Logged By: BN REMARKS 2 N tion USCS Descri w p N s y 'N o w a O w T d - !' „ o o °' Note: BGS = Below Ground Surface Fat CLAY (Native) - brown, CL Moderate vegetation stiff to very stiff, moist. and organics observed 4.5+ to 6 inches BGS. 1 BG 95 28'1 2.0 Atterberg Limits: LL=57, PI=35 Silty SAND - tan, dense, SM moist. • • 3 • • • Weak cementation • • • observed from 3 to • . ' 4 feet BGS. • BG 4 ••• 5 (B_28_06) Poorly -Graded GRAVEL with GP Sand - tan, dense, moist to saturated. 7 O: 8 p. O 9 � Test pit terminated at 10 Standpipe piezometer feet BGS. installed to 10 feet BGS. 11 12 13 14 15 Client:450100 Test Pit Number: TP -5 EXPLORATORY TEST PIT LOG s T RaT a WxC6::h W -r^',+rF�'""-c�We:i"r Sheet 1 of 1 Project: B061 67A Date Excavated: 8-7-2006 Backhoe: CASE 580 SUPER Bucket Width: 2' Depth to Groundwater: 6.2' Logged By: BN Lean CLAY (Native) — brown,I CL moist. stiff to very stiff, 2 Sandy SILT — tan, firm. ML slightly, moist. 3 REMARKS a tis EXPLORATORY %TEST PIT LOG s T Ft aT a al"".�"`rF°""""^'"''"r _ Sheet 7 of 1 T a Backhoe: CASE 580 SUPER o` v Logged By: BN USCS Description 7 <F-2 o Note: BGS = Below Ground a E Surface SILT — brown, stiff, moist. ML Moderate vegetation and organics observed to 6 inches BGS. Lean CLAY (Native) — brown,I CL moist. stiff to very stiff, 2 Sandy SILT — tan, firm. ML slightly, moist. 3 4 Client: Test Pit Number: TP -7 EXPLORATORY %TEST PIT LOG s T Ft aT a al"".�"`rF°""""^'"''"r _ Sheet 7 of 1 5 Date Excavated: 8-7-2006 Backhoe: CASE 580 SUPER Bucket Width: 2' 6 Logged By: BN 7 Poorly—Graded GRAVEL with GP Sand — tan, dense, moist to saturated. 9 10 IN C Test pit terminated at 11 Standpipe piezomete feet BGS. installed to 11 feet BGS. 12 13 14 15 Client: Test Pit Number: TP -7 EXPLORATORY %TEST PIT LOG s T Ft aT a al"".�"`rF°""""^'"''"r _ Sheet 7 of 1 Project: B06167A Date Excavated: 8-7-2006 Backhoe: CASE 580 SUPER Bucket Width: 2' Depth to Groundwater: N/A Logged By: BN �a v REMARKS USCS Description a m w a y y N v _ p - Note: BGS — Below Ground e Surface Lean CLAY (Native) — brown, CL etation erate gobserved stiff to very stiff, moist. enddorganics gG to 6 inches BGS. 1 Weakly cemented from Sandy SILT — tan, very stiff MIL to hard, slightly, moist. LK 1.5 to 4.5 feet BGS. 2 3 BG 4 Silty SAND — tan, dense, SM moist. 5 ' BG 6 •'• 7 8 9 10 ' Test pit terminated at 11 feet BGS. 12 13 14 15 Client: Test Pit Number: TP -8 EXPLORATORY TEST PIT LOG :'4^"'�`rF�a�^-ei ,.��"'r: Sheet oft Project: B06167A Date Excavated: 8-7-2006 Backhoe: CASE 580 SUPER Bucket Width: 2' Depth to Groundwater: N/A Logged By: BN 2 REMARKS USCS Description N a N 5 o yo .12 a o m 5 Note: BGS = Below Ground m o„ d a- E Surface SILT (Fill) — brown, firm, ML Moderate vegetation slightly moist. With grass and organics observed clippings. to 4 feet BGS. 1 BG 2 3 Sandy SILT (Native) — tan, ML firm, slightly, moist. BG Moderate cementation observed from 5 to Silty SAD — tan, dense, SM • • • moist. • • • 6.5feet BGS. ••o •o Silty SAND with Cobbles — SM tan, dense, moist. • � o 7 o ' Maximum cobble size 12 inch diameter. Poorly—Graded SAND with SP ' Cobbles — tan, dense, moist. o s o 9 3 a • o a a 3 O O Test pit terminated at 10 feet BGS. 11 12 13 14 15 Client: Test Pit Number: TP -9 EXPLORATORY T TEST PIT LOG Project: 806167A Date Excavated: 8-7-2006 Backhoe: CASE 580 SUPER Bucket Width: 2'aT Gi n��faiNY F uMNw: n:�xp Sheet 1 of 1 Depth to Groundwater: N/A Logged By: BN O I REMARKS USCS Description J o m a F> dy o v o v F2 Note: BGS = Below Ground E Surface Clayey SAND (Native) — SC • • 4.5+ Moderate vegetation brown, dense, moist. • and organics observed • • ' to 6 inches BGS. 1 • • • f • ' f �g� 19 18.5 1.5-1.0 Atterberg Limits: • LL=37, P1=18 LeanCLAY with Sand — tan, CL stiff, moist. 3 BG Silty SAND with Gravel — tan, SM dense, moist. • f • • f • f 5 6 •'. 7 8 ' ! • f • • f 9 ! f • f • 10 • • ' ! • f f Test pit terminated at 11 Standpipe piezometer feet BGS. installed to 11 feet BGS. 12 13 14 15 Client: Test Pit Number: TP -10 EXPLORATORY TEST PIT LOG S T K amf a Project: B061 67A Date Excavated: 8-7-2006 Backhoe: CASE 580 SUPER Bucket Width: 2' t^"3�"yF°'i'"^yam'^°"� Sheet 1 of 1 Depth to Groundwater: N/A Logged By: BN H w REMARKS USCS Description J w o d Note: BGS = Below Ground Surface Lean CLAY — brown, hard, CL Moderate vegetation moist. and organics observed to 6 inches BGS. 1 4.5+ Moderate cementation observed froml.5to BCi 4.5+ 3.5 feet BGS. Sandy SILT — tan, firm, ML slightly, moist. 3 Silty ton, dense, SM moist. 4 5 Poorly—Graded GRAVEL withGP ' Sand — tan, dense, moist to .� saturated. 7 e � s D: p. Test pit terminated at 10 feet BGS. 11 12 13 14 15 Client: r Test Pit Number: TP -15 EXPLORATORY TEST PIT LOG S T K Wr a LLSO![L�n.-Cnt[11."FFarryy Sn.v[uV,.ti !r.!. uxC Sheet 1ofI Project: B06167A Date Excavated: 8-7-2006 Backhoe: CASE 580 SUPER Bucket Width: 2' Depth to Groundwater: N/A Logged By: BN 3 Silty SAND - ton, dense, SM moist. REMARKS �v U1N O Jd 'NDN Cw YOY USCS Description o ca F a= Note: BGS = Below Ground • 5 o E Surface U • Lean CLAY (Native) - brown, CL Moderate vegetation stiff to very stiff, moist. and organics observed 3.5 to 6 inches BGS. 1 9 82 18.2 1.5-2.0 Atterberg Limits: 2 LL=30, P1=8 3 Silty SAND - ton, dense, SM moist. 4 • 5 • roony-braaea bKAVLL wrtn GP v . Sand - tan, dense, moist to 6 saturated. O 7 8 (8-28-06) 9 10 D Test pit terminated at 11 feet L B061 67A to Groundwater: 8.6 12 13 14 15 Test Pit Number: TP -16 Date Excavated: 8-7-2006 Bucket Width: 2' Logged By: BN 1.5-2.0 Standpipe piezometer installed to 11 feet BGS. EXPLORATORYI TEST PIT LOG Sheet 1 of 1 �� � i � �� � a. a �� �I�' �I •� C. POST -DEVELOPMENT DRAINAGE AREAS MAP and Stormwater Calculations c N FFoy / m i �m c`i"io O ri E �m � n�°mvry 0 W Ztl/ \ l rn Ta Y-olr.� ACHD Calculation Sheet for Sizing Rural Swale/Borrow Ditch NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. User input in yellow cells. To accept default value type = in yellow cell and point to computed cell 1 Project Name Southern Highlands Subdivision Phase II c ❑mer numoer or nurai �waies/nurrow uncnes Iv max) 1 3 Design Storm 100 Weighted Runoff Coefficient C 0-85 Link to: [Q,v� 4 Area A (Acres) 0.16 acres Peak Qv Ta55 — Approved discharge rate for the given storm (if applicable) 0.00 cfs 5 Design Vol With 0% Sed for Swales V 548 548.00 ft' 6 Length of Swale 175 ft 7 Sand Bottom for Infiltration? (Note: infiltration required if Longitudinal Sloped%) Design Infiltration Rate 8 in/hr 8 Sand Window Width 2.00 ft 9 Set Swale Bottom Width b 0.00 ft 10 Set Swale Top Width 8.00 ft 11 Set Swale Depth y 1.00 ft 12 Swale Side Slopes H:1 Sxs 4.00 13 Calculate cross-sectional area Axs Axs=yzz+by 14 Total Swale Capacity Without Driveways 15 Does it Have Capacity? 16 Time to Drain 90% volume in 24 -hours minimum Check Swale With Driveways 17 Avg. Driveway Fill Slope in Swale 18 Enter Total Number of Driveways 19 Enter Total Length of all Driveways 20 Lost Swale Length From Trees, etc. 21 Adjusted Length of Infiltration Area 4.00 4.00 ft' 700 700.00 ft' 2.3 0.25 hr (H/V) 0.00 ft/ft 0 ea 22 Excess Capacity = Storage - Deductions - Runoff Volume 23 Is Capacity Good? 24 Time to Drain 90% volume in 24 -hours minimum Oft Oft 175.0 ft 152.0 ft' YES 5.2 hr OK 0.0 ft' Deduct driveway slope 0.0 ft3 Deduct driveway length 0.0 ft' Deduct other H:\12015\BE-382-1504 Sky Mesa Phase II\Project Data\Working\ERB\Official Calcs\ACHD_SD_CALCS_1-19-15 - Borrow Ditch.xlsm 7/9/2015, 9:46 AM Version 7.8, January 2015 B ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method NOTE: This worksheet is Intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. yellow cells: To accept default value type= In yellow cell and point to I Project Name Southern Highlands 11 2 Is area drainage basin map provided? (map must be included with stormwater calculations) 3 Enter Design Storm For Volume (100 -year per ACHD policy) 4 Enter number of storage facilities (25 max) 5 Area of Drainage Subbasin (SF or Acres) YES 100 4 1 5u1ibasln2 3 4 5 803,626 1 6 6 Determine the Weighted Runoff Coefficient (C) I am C=[(C1xA1)+(C2xA2)+(CnxAn)j/A Weighted Avg 0.40 7 Calculate Overland Flow Time of Concentration In Minor,, (To) or us.defau1t 10 [IJar GA.uldle� 1n KIP, min Pipe Size ID (Inl Slope (H/k) Intercept Coeff. Length Manning n Hydraulic Radius A/Wet Perm Flow velocityV (fps) Flow Time (min) Segment 1: Pi a Flow a 035-0.50 060-0]5 Residential pian) 025-O40 095 Alum,—t dwelling areas 0.70 80th Indumiai and Commereml cant areas Heavy areas O,W 090 Enter WQ Volume (V,,,e= Cxi (from line above_) xM3600) ParW. cemeteries 010-025 IS ,, ft' Segment 2: Gutter Shallow Concentrated Flow b 1 0.619 cfs 14 Volume Summary C D FIM 0iAverage2-6X a.p6 Surface Storage. Pond 011 0.35 Segment 3: Overland Sheet Flaw By TR -55, <300 -ft C V 1,802 ¢ep sfiX ft' Primary Treatment/Storage Basin V 16,185 Subbasin I Subteein I Subbasin I Subba ] 8 9 to ampureu ic= PleVpvunds 0.20-035 user -Entered To -1 15.0 Railroad Vartl areas o30 -0A0 8 Determine the average rainfall intensity (1) from IDF Curve based on ! 2.63 2.62 In/ 9 Calculate the Post -Development peak discharge(QPeak) Ol 14:52 14.52 cfs 10 Calculate peak Qwp(uses 2 -yr storm) Over 5.65 cfs (used for S/G Trap throat velocity, W Q storm conveyance system sizing) 11 Calculate total runoff vol (V)(for sizing primary storage) ea imated flunoff C,eIfic nisfor Various surfaces 22,966 7, of Surface flunoff e—fifrciems "c" V = Cl (Tc=60)A%3600 flue OownMwn at.. urban majdadorhoodareas 0.70-095 050-070 RSPhaR ResEerr6al Single-family MUM -family 035-0.50 060-0]5 Residential pian) 025-O40 095 Alum,—t dwelling areas 0.70 80th Indumiai and Commereml cant areas Heavy areas O,W 090 Enter WQ Volume (V,,,e= Cxi (from line above_) xM3600) ParW. cemeteries 010-025 IS ,, ft' 13 Detan sonApproved Discharge Hate to Surface Waters (If applies ble) ampureu ic= PleVpvunds 0.20-035 user -Entered To -1 15.0 Railroad Vartl areas o30 -0A0 8 Determine the average rainfall intensity (1) from IDF Curve based on ! 2.63 2.62 In/ 9 Calculate the Post -Development peak discharge(QPeak) Ol 14:52 14.52 cfs 10 Calculate peak Qwp(uses 2 -yr storm) Over 5.65 cfs (used for S/G Trap throat velocity, W Q storm conveyance system sizing) 11 Calculate total runoff vol (V)(for sizing primary storage) V 22,966 22,970 1. V = Cl (Tc=60)A%3600 RSPhaR 12 Calculate Vwq iforslzing W0fac1111cal) concrete 095 Enter Percentile Storm I(Both percentile -0.34 int o,xk 80th 0.34 In Enter WQ Volume (V,,,e= Cxi (from line above_) xM3600) Vwa. 6,]85 IS ,, ft' 13 Detan sonApproved Discharge Hate to Surface Waters (If applies ble) soil type V.P. cfs 14 Volume Summary C D FIM 0iAverage2-6X a.p6 Surface Storage. Pond 011 0.35 0.09 WQ Pond Forest, +15%sediment V 1,802 ¢ep sfiX ft' Primary Treatment/Storage Basin V 16,185 Adepfed hpm WE ft' Subsurface Storage: Seepage Bed Volume Without Sediment Factor V 22,970 22,970 ft' See 3MP04 Seepage Bed for Design Volume W ith Sediment H:\!2015\BE-382-1504 Sky Mesa Phase ll\ProjectData\Working\ERB\Official Cales\ACHD SD_CALCS_1-19-15-DA I.xlsm Version 7.8, January 2015 bnlmpreved veer 0.10-0.30 streets RSPhaR 095 concrete 095 o,xk 0,05 Rook 095 Baltic Sandyapn soil type V.P. q 9 C D FIM 0iAverage2-6X a.p6 0.0] 011 0.35 0.09 011 OSs 0.20 ¢ep sfiX 013 0.16 0.23 OSB Adepfed hpm WE ]/9/2015,11:46 AM ACHD Calculation Sheet for Sand/Grease Traps NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. User input in yellow cells. To accept default value type = in yellow cell and point to computed cel 1 Project Name Southern Highlands II Liner nUfn Wer Ul �anWUfedse ieference for Throat widths (inch) of Peak Flow Baffle Throat Boise Velocity Is the Vault Vault Spacing width Area (ftz) 0.5 fps VelocityS/G ENumber Traps Q-cfs inch inch 60.0 max. ok? NQU1000 1 5.65 36 48 12.00 0.47 60 ieference for Throat widths (inch) H:\!2015\BE-382-1504 Sky Mesa Phase II\Project Data\Working\ERB\Official Calcs\ACHD_SD_CALCS_1-19-15 - DA 1.XIsM9/2015, 2:03 PM Version 7.8, January 2015 ADS Boise Lar -ken WQU, Vault BMP 16 1000 G 48.0 50.5 n/a 1500 G 60.0 61.5 n/a NQU1000 n/a n/a 60 NQU1500 n/a n/a 60 H:\!2015\BE-382-1504 Sky Mesa Phase II\Project Data\Working\ERB\Official Calcs\ACHD_SD_CALCS_1-19-15 - DA 1.XIsM9/2015, 2:03 PM Version 7.8, January 2015 I ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new User input in yellow cells. To accept default value type = in yellow cell and point to computed cell 1 Project Name Southern Highlands II 2 Enter number of Seepage Beds (25 max) 3 Design Storm 4 Weighted Runoff Coefficient C 5 Area A(Acres) 6 Approved discharge rate (if applicable) 7 Design Vol W/1-5% Sed for Pero < 8 in/hr V 0% Sediment for Pero z8 in/hr 8 Set Total Design Width of All Drain Rock W 9 Set Total Design Depth of All Drain Rock D Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 for 1.5"-2" drain rock and 3/4" Chips 0.40 13.86 acres 0.00 cis 22,966 75.0 it 9.0 ft 0.4 1 Link to: Peak QV T955 22.970 its 11 Design infiltration Rate (8In/hr max) Perc 8.0 In/hr 12 Size of WQ Perf Pipe (Pert 181 Dia pipe 18 in 13 Size of Overflow Perf Pipe (Perfs 3600) 12 in 14 Calculate Total Storage per Foot Siff 270.3 270.3 ft'/ft Spf=Apf=WxD-Are, pir,xVoids+l/2 Perf—Area 15 Calculate Design Length L 85 345 ft Override Value Required far Chambers 16 Time to Drain 4.9 hours 90% volume in 24 -hours minimum 17 Length of WQ & Overflow Pert Pipes 345 105 ft 18 Perf Pipe Checks. Qperf>= Qpeak; — where Qperf=CdxAxV(2xgxH) 18 in 5.9 >= 5.7 PASS 12 in 9.5 >= 8.9 PASS tis assumes chambers are organized in a rectangular layout. 1 Type of Chambers 1-StormTech, SC740 2 Volume to Store V 0 fts 3 Installed Chamber Width CW 4.25 ft installed Chamber Depth Cd 2.50 it Installed Chamber Length Cl 7.12 it Chamber Void Factor Chamber Storage Volume, Without Rock, Per Manuf 45.90 ft' /Unit Chamber Storage Volume, With Rock, Per Manuf 74.90 ft'/Unit Total Number of Units Required 0 ea 4 Area of Infiltration Aperc ft' 5 Volume Infiltration Vperc 0 ft'/hr 6 Time to Drain hours 9D% volume In 24 -hours minimum H:\015\13E-382-1504 Sky Mesa Phase 11\Project Data\Working\ERB\Official Caos\ACHD_5D_CALCS_1-19-15 - DA 1.xism Version 7.8, January 2015 7/9/2015,11:47 AM ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers NOTE: This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These calculations shall establish a minimum requirement. The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted. Note this spreadsheet pulls information from the "Peak Q,V" tab Calculate Post -Development Flows (for pre -development flows, increase number of storage facilities to create new tab) User input in yellow cells. To accept default value type = In yellow cell and point to computed cell 1 Project Name Southern Highlands Ph. 2 2 Enter number of Seepage Beds 125 max) 4 Weighted Runoff Coefficient C 5 Area A (Acres) 6 Approved discharge rate (if applicable) 7 Design Vol W/15% Sed for Perc <8 in/hr V 0% Sediment for Perc z8 in/hr 8 Set Total Design Width of All Drain Rock W Bed 2 0.40 Link to. 4.27 acres 0.00 is 7 nR1 7 nRi ft, 30.0 it 9 Set Total Design Depth of All Drain Rock D 6.0 It Rock Only, Do Not Include Filter Sand Depth or Cover 10 Void Ratio of Drain Rock Voids 0.4 0.4 for 1.5"-2' drain rock and 3/4" Chips 11 Design Infiltration Rate (81n/hr max) Pert 8A in/hr 12 Size of WC, Perf Pipe (Perf 180') On pipe 18 in 13 Size of Overflow Perf Pipe (Pers 3600) 12 in 14 Calculate Total Storage per Foot Spf 72.3 ft'/ft Spf=Apf=WxD-Ae,rt p,p,xVcdds+1/2 Perf—Area 15 Calculate Design Length L 98 it Override Value Requiredfor Chambers 16 Time to Drain 3.3 hours 90% volume in 24 -hours minimum 17 Length of WQ & Overflow Perf Pipes 98 ft 18 Perf Pipe Checks. Qperf>= Qpeak: where Qperf=CdxAxy(2xgxH) 18 in 5.5 >= 2.1 PASS 12 in 8.8 >_ (0.1) PASS Optional Stora9411111111111111 This assumes chambers are organized in a rectangular layout. 1 Type of Chambers i-StormTech, SC740 2. Volume to Store V 0 it, 3 Installed Chamber Width Cw 4.25 It Installed Chamber Depth Cd 2.50 ft Installed Chamber Length Cl 7.12 it Chamber Void Factor Chamber Storage Volume, Without Rock, Per Manuf 45.90 ft' /Unit Chamber Storage Volume, With Rock, Per Manuf 74.90 ft3/Unit Total Number of Units Required 0 ea 4 Area of Infiltration Aperc ft2 5 Volume Infiltration Vperc 0 ft'/hr 6 Time to Drain hours 90% volume in 24 -hours minimum I:\12015\BE-382-1504 Sky Mesa Phase II\Project Data\Worki ng\TDS\Seep age Bed 2 Calcs.xlsm 7/9/2015, 12:28 PM Version 7.4, July 2014 Project Description File Name.... _ _....... .....__ Sky View S.SPF Description .. ............... .. __.. Southern Highlands Ph 2 Project Options Flow Untie .......... --- .................... ........._..._..._.._._.._..._... CFS Elevation Type ...... ............ ...................................... ............ Elevation Hydrology Method .................................. ....... ...................... Rational Time of Concentration (TOC) Method .................................. User -Defined Link Routing Method ............................. .............. .............. ... Kinematic Wave Enable Overflow Ponding at Nodes ....... ........ ..... -- .......... ... YES Skip Steady State Analysis Time Periods .............. ............. NO Analysis Options Start Analysis On.. .... ....... .................................................... Jul 09, 2015 000000 End Analysis On ... ............ .......................... ............ ........... . Jul 09, 2015 01:00:00 Start Reporting On ................. ........ .......... ............................ Jul 09, 2015 00:00:00 Antecedent Dry Days .................. ...... ........ ........................... 0 days Runoff (Dry Weather) Time Step .......................................... 0 01:0000 days hh:mm:ss Runoff (Wet Weather) Time Step ........................................ 0000500 days hh:mm:ss Reporting Time Step ................... __...._.............................. 0 00:05:00 days hh:mm:ss Routing Time Step ..... .................................. ......_............... 30 seconds Number of Elements Rainfall Details. Return Period........................................................................ 2 year(s) Qty RainGages ... ............................. ............. .................. ........._. 0 Subbasins.............................................................................. 0 Nodes........... ............................... ,......................................... 15 Junctions....................._............................................ .............................................. 13 Outtalls......................................................................... 2 Flow Diversions ..................................... -.................... 0 Inlets............... ................ .........__....__............__..._. 0 StorageNodes............................................................. 0 Links...................................................................................... 13 Channels...................................................................... 0 Pipes............................................................................ 13 Pumps.......................................................................... 0 Orifices......................................................................... 0 weirs............................................................................ 0 Outlets.......................................................................... 0 Pollutants................ ...... ................ ...................._.._........._. 0 LandUses ........... ......... _.................................................... 0 Rainfall Details. Return Period........................................................................ 2 year(s) Node Summary SN Element Element Invert Ground/Rim Initial Surcharge Forded Peak Max HGL Max Min Time of Total Total Time ID Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge Freeboard Peak Flooded Flooded Elevation Elevation Attained Depth Attained Flooding Volume Attained Occurrence (ft) (f) (ft) (ft) (ft') (cfs) (fi) (ft) (ft) (days hh:mm) (ac -In) (min) 1 CB 1 Junction 2674.36 2678.85 2674.36 0.00 10.00 12.87 2675.46 0.00 3.39 0 0000 0.00 0.00 2 CB 2 Junction 2675.25 2678.85 2675.25 0.00 10.00 3.51 2675.65 0.00 3.21 0 00:00 0.00 0.00 3 CB 3 Junction 2678.15 2681.16 2678.15 2681.16 10.00 2.30 2678.68 0.00 2.48 0 0000 0.00 0.00 4 CB 4 Junction 2677.86 2682.37 2677.86 2682.37 10.00 2.04 2678.35 0.00 4.02 0 00:00 0.00 0.00 5 CB 5 Junction 2677.80 2682.37 2677.80 2682.37 10.00 3.19 2678.28 0.00 4.09 0 0000 0.00 0.00 6 CB 6 Junction 2672.07 2675.25 2672.07 2675.25 10.00 1.79 2672.52 0.00 2.73 0 0000 0.00 0.00 7 CB 7 Junction 2671.76 2675.26 2671.76 2675.26 10.00 4.71 2672.43 0.00 2.82 0 00:00 0.00 0.00 8 SDMH 1 Junction 2674.63 2678.95 2674.63 0.00 10.00 11.04 2675.81 0.00 3.14 0 00:00 0.00 0.00 9 SDMH 2 Junction 2675.25 2679.84 2675.25 0.00 10.00 7.53 2676.43 0,00 3.41 0 00:00 0.00 0.00 10 SDMH 3 Junction 2676.61 2682.25 2676.61 2682.25 10.00 7.54 2677.91 0.00 4.34 0 00:00 0.00 0.00 11 SDMH 4 Junction 2677.62 2682.53 2677.62 2682.53 10.00 5-54 2678.39 0.00 4.15 0 00:00 0.00 0.00 12 SDMH 5 Junction 2678.10 2681.98. 2678.10 2681.98 10.00 2.38 2678.78 0.00 3.21 0 0000 0.00 0.00 13 SDMH 6 Junction 2674.26 2677.47 2674.30 0.00 10.00 12.87 2675.48 0.00 1.98 0 00:00 0.00 0.00 140ut-1Pipe-(71) Outfall 2674.20 12.87 2675.42 15 Out -1 Pipe -(76)(1) Outfall 2671.50 4.89 2672.19 Link Summary SN Element Element From To (Outlet) Length Inlet Outlet Average Diameter or Mannings Peak Design Row Peak Flow/ Peak Flow Peak Flow Peak Flaw Total Time Reputed ID Type Onlet) Node Inved Inved Slope Height Roughness Flow Capacity Design Flow Velocity Depth Depth/ Surcharged Condition Node Elevation Elevation Ratio Total Depth Ratio (a) (A) A N (in) (cfs) (cts) (Msec) (1h (min) IPipe -(40) Pipe SDMH5 SDMH3 198.66 2678.10 2677.11 0.5000 12.000 0.0110 2.31 2.87 0.78 4.19 0.66 0.66 0.00 Calculated 2 Pipe -(41) Pipe SDMH3 SDMH2 338.77 2676.61 2675.25 0.4000 18.000 0.0110 7.53 7.87 0.96 5.07 1.18 0.78 0.00 Calculated 3 Pipe -(41)(1) Pipe SDMH2 SDMH1 154.89 2675.25 2674.63 0.4000 18.000 0.0110 7.53 7.85 0.96 5.06 1.18 0.79 0.00 Calculated 4 Pipe -(42) Pipe SDMH1 CB 27.09 2674.63 2674.36 1.0000 18.000 0.0110 11.04 12.39 0.89 7.92 1.10 0.74 000 Calculated 5 Pipe -(43) Pipe CBI SDMH6 6.50 2674.36 2674.26 1.5400 18.000 0.0110 12.87 15.40 0.84 9.75 1.05 0.70 0.00 Calculated 6 Pipe -(45) Pipe CB2 SDMH 1 3.92 2675.25 2675.00 6.3800 12.000 0.0110 3.55 10.63 0.33 12.23 0.40 0.40 0.00 Calculated 7Pipe -(46) Pipe CB SDMH5 5.06 2678.15. 2678.10 0.9900 12.000 0.0110 2.38 4.19 0.57 5.56 0.53 0.53 0.00 Calculated 8 Pipe -(47) Pipe CB SDMH4 6.88 2677.80 2677.62 2.6200 12.000 0.0110 3.28 6.81 0.48 8.67 0.48 0.49 0.00 Calculated 9Pipe -(48) Pipe SDMH4SDMH3 25.80 2677.62 2677.11 1.9800 12.000 0.0110 5.81 5.92 0.98 8.78 0.73 0.79 0.00 Calculated 10 Pipe -(49) Pipe CB SDMH4 24.13 2677.86 2677.62 0.9900 12.000 0.0110 2.27 4.20 0.54 5.66 0.49 0.51 0.00 Calculated 11 Pipe - (52) (1) Pipe CBS CB 31.03 2672.07 2671.76 1.0000 12.000 0.0110 2A1 4.21 0.48 5.54 0.45 0.47 000 Calculated 12 Pipe -(71) Pipe SDMH6 Out-1Pipe-(71) 5.50 2674.26 2674.18 1.4500 18.000 0.0110 12.87 12.97 0.99 8.36 1.22 0.81 0.00 Calculated 13 Pipe -(76)(1) Pipe CB Out-1Pipe -(76)(1) 16.72 2671.76 2671.50 1.6500 12.000 0.0100 4.89 5.96 0.82 8.59 0.65 0.68 0.00 Calculated Junction Input SN Element Invert Ground/Rim Ground/Rim Intgal Initial Surcharge Surcharge Ponded Minimum ID Elevation (Max) (Max) Water Water Elevation Depth Area Pipe Elevation Offset Elevation Depth Cover tft) (It) (ft) (ft) (ft) 0t) (fl) (ft) (In) 1 CB 1 2674.36 2678.85 4.49 2674.36 0.00 0.00 -2678.85 10.00 35.90 2 CB 2 2675.25 2678.85 3.60 2675.25 0.00 0.00 -2678.85 10.00 31.23 3 CB 3 2678.15 2681.16 3.01 2678.15 0.00 2681.16 0.00 10.00 24.09 4 CB 4 2677.86 2682.37 4.51 2677.86 0.00 2682.37 0.00 10.00 42.15 5 CB 5 2677.80 2682.37 4.57 2677.80 0.00 2682.37 0.00 10.00 42.87 6 CB 6 2672.07 2675.25 3.18 2672.07 0.00 2675.25 0.00 10.00 26.20 7 CB 7 2671.76 2675.26 3.50 2671.76 0.00 2675.26 0.00 10.00 29.95 8 SDMH 1 2674.63 2678.95 4.32 2674.63 0.00 0.00 -2678.95 10.00 33.82 9 SDMH 2 2675.25 2679.84 4.59 2675.25 0.00 0.00 -2679.84 10.00 37.06 10 SDMH 3 2676.61 2682,25 5.64 2676.61 0.00 2682.25 0.00 10.00 49.74 11 SDMH 4 2677.62 2682.53 4.91 2677.62 0.00 2682.53 0.00 10.00 46.96 12 SDMH 5 2678.10 2681.98 3.88 2678.10 0.00 2681.98 0.00 10.00 34.60 13 SDMH 6 2674.26 2677.47 3.21 2674.30 0.04 0.00 -2677.47 10.00 20.46 Junction Results SN Element Peak Peak Max HGL Max HGL Max Min Average HGL Average HGL Time of Time of Total Total Time ID Inflow Lateral Elevation Depth Surcharge Freeboard Elevation Depth Max HGL Peak Flooded Flooded Inflow Attained Attained Depth Attained Attained Attained Occurrence Flooding Volume Attained Occurrence _ (ds) (cfs) (fl) (it) (it) (ft) (it) (ft) (days hh:mm) (days hh:mm) (ac -In) (min) 1 CB 1 12.87 1.83 2675.46 1.10 0.00 3.39 2675.45 1.09 0 00:14 0 0000 0.00 0.00 2 CB 2 3.51 3.51 2675.65 0.40 0.00 3.21 2675.65 0.40 0 0000 0 0000 0.00 0.00 3 CB 3 2.30 2.30 2678.68 0.53 0.00 2.48 2678.68 0.53 0 00:00 0 00:00 0.00 0.00 4 3134 2.04 2.04 2678,35 0.49 0.00 4.02 2678.35 0.49 0 0000 0 0000 0.00 0.00 5 CB 5 3.19 3.19 2678.28 0.48 0.00 4.09 2678.28 0.48 0 00:00 0 00:00 0,00 0.00 6 CB 6 1.79 1.79 2672.52 0.45 0.00 2.73 2672.52 0.45 0 0000 0 0000 0.00 0.00 7 CB 7 4.71 2.70 2672.43 0.67 0.00 2.82 2672.41 0.65 0 00:01 0 00:00 0.00 0.00 8 SDMH 1 11.04 0.00 2675.81 1.18 0.00 3.14 2675.79 1.16 0 0010 0 0000 0.00 0.00 9 SDMH 2 7.53 0:00 2676.43 1.18 0.00 3.41 2676.41 1.16. 0 00:08 0 00.'00 0.00 0.00 10 SDMH 3 7.54 0.00 2677.91 1.30 0.00 4.34 2677.84 1.23 0 0001 0 00:00 0.00 0.00 11 SDMH 4 5.54 0.00 2678.39 0.77 0.00 4.15 2678.35 0.73 0 00:01 0 00:00 0.00 0.00 12 SDMH 5 2.38 0.00 2678.78 0.68 0.00 3.21 2678.76 0.66 0 00:01 0 00:00 0.00 0.00 13 SDMH 6 12.87 0.00 2675.48 1.22 0.00 1.98 2675.46 1.20 0 00:07 0 00:00 0.00 0.00 Pipe Input SN Element Length Inlet Inlet Outlet Outlet Total Average Pipe Pipe Pipe Manning's Entrance Exit/Bend Additional Initial Flap No. of ID Invert Invert Invert Invert Drop Slope Shape Diameter or Width Roughness Losses Losses Losses Flow Gate Barrels Elevation Offset Elevation Offset Height (ft) (ft) (ft) N (ft) (ft) N (in) (in) (cis) 1 Pipe -(40) 198.66 2678.10 0.00 2677.11 0.50 0.99 0.5000 CIRCULAR 12.000 12.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 2 Pipe -(41) 338.77 2676.61 0.00 2675.25 0.00 1.36 0.4000 CIRCULAR 18.000 18.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 3 Pipe -(41) (1) 154.89 2675.25 0.00 2674.63 0.00 0.62 0.4000 CIRCULAR 18.000 18.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 4 Pipe -(42) 27.09 2674.63 0.00 2674.36 0.00 0.27 1.0000 CIRCULAR 18.000 18.000 0.0110 0.5000 0.5000 0.0000. 0.00 No 1 5 Pipe -(43) 6.50 2674.36 0.00 2674.26 0.00 0.10 1.5400 CIRCULAR 18.000 18.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 6 Pipe -(45) 3.92 2675.25 0.00 2675.00 0.37 0.25 6.3800 CIRCULAR 12.000 12.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 7 Pipe -(46) 5.06 2678.15 0.00 2678.10 0.00 0.05 0.9900 CIRCULAR 12.000 12.000 0.0110 0.5000 0.5000 0.0000 000 No 1 8 Pipe -(47) 6.88 2677.80 0.00 2677.62 0.00 0.18 2.6200 CIRCULAR 12.000 12.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 9 Pipe -(48) 25.80 2677.62 0.00 2677.11 0.50 0.51 1.9800 CIRCULAR 12.000 12.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 10 Pipe -(49) 24.13 2677.86 0.00 2677.62 0.00 0.24 0.9900 CIRCULAR 12.000 12.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 11 Pipe -(52) (1) 31.03 2672.07 0.00 2671.76 0.00 0.31 1.0000 CIRCULAR 12.000 12.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 12 Pipe -(71) 5.50 2674.26 0.00 2674.18 -0.02 0.08 1.4500 CIRCULAR 18.000 18.000 0.0110 0.5000 0.5000 0.0000 0.00 No 1 13 Pipe -(76) (1) 15.72 2671.76 0.00 2671.50 0.00 0.26 1.6500 CIRCULAR 12.000 12.000 0.0100 0.5000 0.5000 0.0000 0.00 No 1 Pipe Results SN Element Peak Time of Design Flow Peak Flow/ Peak Flow Travel Peak Flow Peak Flow Total Time. Froude Reported ID Flow Peak Flow Capacity Design Flow Velocity Time Depth Depth/ Surcharged Number Condition Occurrence Ratio Total Depth Ratio (cfs) (days hh:mm) (cfs) (ft/sec) (min) (fry (min) 1 Pipe -(40) 2.31 0 00:03 2.97 0.78 4.19 0.79 0.66 0.66 0.00 Calculated 2 Pipe -(41) 7.53 0 00:08 7.87 0.96 5.07 1.11 1.18 0.78 0.00 Calculated 3 Pipe -(41)(1) 7.53 000:10 7.85 0.96 5.06 0.51 1.18 0.79 0.00 Calculated 4 Pipe -(42) 11.04 000:14 12.39 0.89 7.92 0.06 1.10 0.74 0.00 calculated 5 Pipe -(43) 12.87 0 00:07 15.40 0.84 9.75 0.01 1.05 0.70 0.00 Calculated 6 Pipe -(45) 3.55 000`01 10.63 0.33 12.23 0.01 0.40 0.40 0.00 Calculated 7 Pipe -(46) 2.38 0 00:01 4.19 0.57 5.56 0.02 0.53 0.53 0.00 Calculated 8 Pipe -(47) 3.28 0 00:01 6.81 0.48 8.67 0.01 0.48 0.49 0.00 Calculated 9 Pipe -(48) 5.81 0 00:01 5.92 0.98 8.78 0.05 0,73 0.79 0.00 Calculated 10 Pipe -(49) 2.27 0 00:01 4.20 0.54 5.66 0.07 0.49 0.51 0.00 Calculated 11 Pipe -(52)(1) 2.01 0 00:01 421 0.48 5.54 0.09 0.45 0.47 0.00 Calculated 12 Pipe -(71) 12.87 0 00:07 12.97 0.99 8.36 0.01 1.22 0.81 0.00 Calculated 13 Pipe -(76) (1) 4.89 0 00:01 5.96 0.82 8.59 0.03 0.65 0.68 0.00 Calculated D. RATIONAL METHOD RUNOFF C -COEFFICIENTS Categorized by surface Forested 0.059-0.2 Asphalt 0.7-0.95 Brick 0.7-0.85 Concrete 0.8-0.95 Shingle roof 0.75-0.95 Lawns, well -drained (sandy soil) 0.2-0.35 up to 2% slope 0.05-0.1 2% to 7% slope 0.10-0.15 over 7% slope 0.15-0.2 Lawns, poorly drained (clay soil) 0.7-0.95 up to 2% slope 0.13-0.17 2% to 7% slope 0.18-0.22 over 7% slope 0.25-0.35 Driveways, walkways 0.75-0.85 Categorized by use Farmland 0.05-0.3 Pasture 0.05-0.3 Unimproved 0.1-0.3 Parks 0.1-0.25 Cemeteries 0.1-0.25 Railroad yards 0.2-0.35 Playgrounds (except asphalt or concrete) 0.2-0.35 Business districts Neighborhood 0.5-0.7 City (downtown) 0.7-0.95 Residential Single family 0.3-0.5 Multiplexes, detached 0.4-0.6 Multiplexes, attached 0.6-0.75 Suburban 0.25-0.4 Apartments, condominiums 0.5-0.7 Industrial Light 0.5-0.8 Heavy 0.6-0.9 E. REGIONAL RAINFALL CURVE CHART 10.0 6.0 7[e7 a 4.0 U x a 2.0 w a. U) = 1.0 U Z 0.8 Z 0.6 r 0.4 Z W Z 0.2 J J Q z Z a .o e .0 6 A 4 .0 2 Exibit `B' I����� �■moi CURVE 13 20 30 40 3060 2 3 4 8 6 8 10 12 18 24 MINUTES DURATION HOURS