GENERAL AND FLOODING STANDARDS SUBMISSION BRUNSWICK LAYOVER FACILITY BRUNSWICK, MAINE PREPARED FOR:

APPENDIX H

GENERAL AND FLOODING STANDARDS SUBMISSION BRUNSWICK LAYOVER FACILITY BRUNSWICK, MAINE PREPARED FOR: NORTHERN NEW ENGLAND PASSENGER RAIL AUTHORITY (NNEPRA) 75 WEST COMMERCIAL STREET, SUITE 104 PORTLAND, MAINE 04101 PREPARED BY: FAY, SPOFFORD & THORNDIKE (FST) (FORMERLY DELUCA-HOFFMAN ASSOCIATES, INC.) 778 MAIN STREET, SUITE 8 SOUTH PORTLAND, MAINE 04106 (207) 775-1121 AUGUST 2014

TABLE OF CONTENTS Section Description Page 1.0 Overview... 1 1.1 Existing Site Conditions... 1 1.2 Existing and Proposed Drainage Features... 1 1.3 Overview of Stormwater Management Concerns... 2 1.4 References... 2 1.5 Overview of Stormwater Runoff Modeling... 3 1.6 Methods of Analysis Stormwater Quantity... 3 1.7 Description of Site Watershed Model... 4 1.8 Predevelopment Watersheds... 4 1.9 Postdevelopment Watersheds... 4 1.10 Stormwater Runoff Analysis... 4 1.11 General Standard Overview... 4 1.12 Treatment Mechanisms... 4 1.13 Flooding Standard Overview... 5 1.14 Urban Impaired Stream Standard... 6 1.15 Maintenance of Facilities... 6 1.16 Conclusions... 6 Plan References Sheet C-4.1 Sheet C-4.2 Sheet C-4.3 Sheet C-5.1 Sheet C-5.2 Sheet C-8.1 Sheet C-8.2 Sheet C-8.3 Grading and Erosion Control Plan Grading and Erosion Control Plan Grading and Erosion Control Plan Wet Pond Sections Wet Pond Details Predevelopment Watershed Map Postdevelopment Watershed Map Water Quality Plan Attachments A Pre and Post Development Hydrocad Computations B Water Quality Treatment Computations C Pipe Sizing/Hydraulic Computations D Flood Insurance Rate Map E Inspection & Maintenance Manual F Urban Impaired Stream Watershed Map

1.0 Overview The Northern New England Passenger Rail Authority (NNEPRA) in cooperation with the Federal Railroad Administration (FRA) is proposing to construct a passenger rail equipment layover facility in Brunswick, Maine. The facility will support expansion of the Amtrak Downeaster passenger rail service. The proposed facility will be located at the site of the Brunswick freight rail yard located between Church Road and Stanwood Street. The proposed facility will be located approximately 0.6 miles west of Brunswick Station which is the current eastern terminus of Amtrak Downeaster. The proposed project will create over four acres of impervious area and over six acres of disturbed area. The project is exempt from requiring a Site Location of Development Permit under Federal Law at 49 U.S.C. 24902(j); refer to Appendix E. The proposed project, however, will require a Stormwater Management Law Permit and is required to meet the Basic, General, and Flooding Standards. FST (formerly DeLuca-Hoffman Associates, Inc.) completed this stormwater management analysis to confirm that the planned development would not result in any significant impacts downstream of the development site above the predevelopment conditions and would not create potential degradation of water quality to locations downstream of the development site in accordance with the MeDEP Chapter 500 Regulations. 1.1 Existing Site Conditions The watershed area considered for this stormwater report is approximately 13.6 acres mainly consisting of the Brunswick West Rail Yard but also portions of adjacent lots to the north. Topography on the site ranges from approximately elevation 92 at the west side of the parcel near Church Road to approximately elevation 78 to the east. The site generally drains from west to east to an unnamed stream tributary to the Androscoggin River. Test pit explorations were conducted by Summit GeoEngineering in areas within close proximity to the proposed wet pond as well as other areas throughout the site. Borings B-3, B-5, and B-6 are closest in proximity to the wet pond. Logs for these borings are included in Appendix D. The locations of the borings performed can be found on Sheets C-4.1, C-4.2, C-4.3, and C-5.1 of the accompanying. Soils on the site consist mostly of a mix of Hydrologic Soils Group (HSG) A (Windsor) Soils and HSG B (AuGres) Soils, as indicated by the Natural Resources Conservation Service. 1.2 Existing and Proposed Drainage Features The existing site drainage is generally overland flow with minimal formal structural stormwater facilities. For the purpose of this analysis, two Points of Interest (POI) were evaluated. The locations of these POI s are shown on Sheets C-8.1 and C-8.2. The stormwater management BMPs have been sized to manage the stormwater runoff from the developed areas such that the flows at the two POI s will be maintained at or below predevelopment conditions. POI #1 is a granite box culvert passing beneath the existing railroad tracks. The upstream (south) end is approximately 38 wide by 42 deep. The downstream opening is approximately 48 wide by 29 deep. The area tributary to POI #1 is comprised of most of the project site and a JN3203 General and Flooding Standards August 2014 Page 1 Brunswick Layover Facility Brunswick, ME

ditch that extends along the southern boundary of the Maine DOT right of way. POI #1 discharges to an unnamed stream which is tributary to the Androscoggin River. POI #2 includes the drainage area of Predevelopment Subcatchment #3. Flow is distributed evenly across the east property line towards an unnamed stream tributary to the Androscoggin River. Stormwater management goals for the project have been established for two areas: Stormwater quantity goals based on MeDEP criteria (Flooding Standard) to maintain postdevelopment peak flow rates to at or below predevelopment levels. Stormwater quality goals based on MeDEP criteria (General Standard) utilizing one water quality wet pond. This will provide both water quality volume and channel protection volume. Channel protection volume will be addressed by detention of stormwater and releasing it more slowly. An outlet control structure and emergency spillway will regulate Stormwater in excess of the channel protection volume. 1.3 Overview of Stormwater Management Concerns Given the challenges associated with redevelopment and the limited available proximate space for development, the following factors were considered in the analysis: Collection of stormwater runoff from proposed developed surfaces and discharge to the stormwater management BMPs where stormwater quantity control and water quality treatment will be provided. Collection of stormwater runoff from existing impervious surfaces. 1.4 References The following reference sources were reviewed during preparation of this stormwater analysis: 1. Section 4 Hydrology, USDA Soil Conservation Service, March 1985 2. Technical Release Number 55 Urban Hydrology for Small Watersheds, USDA Soil Conservation Service, June 1986 3. HydroCAD Technical Reference Manual, Applied Micro-Computer System, 1995 4. Maine Erosion and Sedimentation Control Handbook for Construction: Best Management Practices, MeDEP, March 1991 5. Stormwater Management, Best Management Practices, MeDEP, Latest Revision The following reference sources were used for preparation of this stormwater quality analysis: 1. Reducing the Impacts of Stormwater Runoff from New Development New York State Department of Environmental Conservation, April 1993 2. Stormwater Management, Best Management Practices, MeDEP, Latest Revision 3. EPA Urban Targeting and BMP Selection Terrene Institute, November 1990 4. Urbanization and Water Quality Terrene Institute, March 1994 JN3203 General and Flooding Standards August 2014 Page 2 Brunswick Layover Facility Brunswick, ME

5. A Current Assessment of Urban Best Management Practices, Techniques for Reducing Non-point Source Pollution in the Coastal Zone, U.S.E.P.A. Office of Watersheds, March 1992 Computer programs used to assist in the various components of this analysis included: 1. HydroCAD Stormwater Modeling System, version 8.5, Applied Microcomputer Systems used for modeling watersheds for pre and postdevelopment conditions. 2. Microsoft Excel 2003 used for spreadsheet computations. 3. Hydra Flow Storm Sewer Extension for AutoCAD Civil 3D 2013 Used for hydraulic modeling of underground conveyance system. Data resources used to obtain the hydrologic input data for the stormwater computer model have been identified in Section 1.6 of this report. 1.5 Overview of Stormwater Runoff Modeling The stormwater analysis evaluates five elements of the project as follows: 1. Analysis of predevelopment and postdevelopment stormwater runoff rates. 2. Review of the potential impacts of the proposed site development and subsequent impacts to site peak discharge rates and locations. 3. Evaluation of the requirements for stormwater management. 4. Evaluation of storm drainage collection and conveyance requirements from proposed impervious surfaces and existing impervious surfaces, and other improvement areas associated with the completed build-out scenario for the planned development. 5. Water quality treatment requirements and methods. 1.6 Methods of Analysis Stormwater Quantity The hydrologic analyses for predevelopment and postdevelopment conditions have been conducted based upon the methodology contained in the USDA Soil Conservation Service s Technical Releases No. 20 and 55 (SCS TR-20 and TR-55). For Cumberland County, Maine, a 24-hour SCS Type III storm distribution was used for the analysis using the following storm frequencies and rainfall amounts. Storm Event 2-Year Storm 10-Year Storm 25-Year Storm 24-Hour Rainfall 3.0 Inches 4.7 Inches 5.5 Inches Land use, cover, delineation of watershed subcatchments, hydraulic flow paths, and hydrologic soil types were obtained using the following data: 1. Cumberland County Soil Survey. 2. Onsite Topographic Survey with 1-foot contour intervals. 3. Field Reconnaissance by FST (formerly DeLuca-Hoffman Associates, Inc.) JN3203 General and Flooding Standards August 2014 Page 3 Brunswick Layover Facility Brunswick, ME

1.7 Description of Site Watershed Model The watershed model attempts to allow the following to be determined: Determine pre and postdevelopment runoff rates; Determine if the peak runoff rates emanating from the site will be increased due to the proposed project; and Determine the ability of the proposed stormwater management system to attenuate flows in the postdevelopment condition to predevelopment levels or lower. 1.8 Predevelopment Watersheds Predevelopment watersheds were constructed using a compilation of aerial photography, record drawings, and on-site ground survey. Attachment A contains a summary listing of the pre development watersheds based on their hydrologic characteristics. 1.9 Postdevelopment Watersheds The postdevelopment watersheds generally maintain the same drainage paths and shapes as the predevelopment watersheds, some of the watersheds have been agglomerated based on the revised drainage paths resulting from changes to site grading. Attachment A contains a summary listing of the post development watersheds based on their hydrologic characteristics. 1.10 Stormwater Runoff Analysis Using the HydroCAD software, predevelopment and postdevelopment watershed characteristics and runoff computations for the overall 13.6-acre watershed area and the development site were established. Attachment A contains the runoff computations and peak flows for each subcatchment within the watershed area in the predevelopment conditions for each storm analyzed. 1.11 General Standard Overview The Brunswick Layover Facility will create approximately 6.7 acres of developed area. Approximately 4.3 acres of the developed area is considered impervious surface. Impervious surfaces included paved and gravel access drives, paved parking areas, roof surface, and railroad ballast. The general standard requires that 95% of a project s impervious area and 80% of the developed area be captured by the stormwater management system. The project will incorporate a wet pond to capture runoff and provide adequate water quality volume (treatment of pollutants) and channel protection volume (mitigation of channel erosive flows). The proposed stormwater management system will capture runoff from proposed developed areas as well as existing areas not proposed to be redeveloped. Attachment B shows treatment percentage calculations. The project will take credit for treatment of undeveloped lawn areas (retrofit credit of 0.30) and existing railroad corridor areas (retrofit credit of 0.60). The treatment percentages calculated for this project exceed the General Standard requirements. Impervious area capture is 106.07% and developed area is 88.42%. 1.12 Treatment Mechanisms The proposed wet pond has a volume of 31,496 cubic feet at a permanent pool elevation of 76 feet. The channel protection elevation is 78.10 feet and is released slowly through a 65 foot underdrain bench which is controlled with a 2 orifice in the outlet control structure. The pond has a mean depth of over 3 feet, and a length-to-width ratio of greater than 2:1. The mean depth JN3203 General and Flooding Standards August 2014 Page 4 Brunswick Layover Facility Brunswick, ME

has been computed at 1 foot below the permanent pool surface. The pond will have a trash rack on the outlet control structure which will also act as the emergency spillway. A detail of the trash rack is contained on the Pond Detail Sheet (C-5.2). All sizing calculations were computed and summarized on a spreadsheet and can be found in Attachment B of this report. 1.13 Flooding Standard Overview The proposed wet pond will receive stormwater runoff partially from the proposed development areas and partially from existing developed areas. The proposed wet pond will provide adequate storage volume to ensure that predevelopment peak flows are not exceeded at each point of analysis in the postdevelopment conditions. The following tables present a summary of pre and postdevelopment flows at each point of analysis with the inclusion of the proposed wet pond. Table 1 Predevelopment vs. Postdevelopment Flow Comparison Predevelopment Flows (cfs) Postdevelopment Flows (cfs) 2-Yr Storm 10-Yr Storm 25-Yr Storm 2-Yr Storm 10-Yr Storm 25-Yr Storm POI 1 0.84 6.76 11.37 0.81 5.57 10.29 POI 2 0.05 0.34 0.54 0.01 0.21 0.37 Table 1A Predevelopment vs. Postdevelopment Volume Comparison Predevelopment Flows (ac-ft) Postdevelopment Flows (ac-ft) 2-Yr Storm 10-Yr Storm 25-Yr Storm 2-Yr Storm 10-Yr Storm 25-Yr Storm POI 1 0.185 0.817 1.221 0.270 1.154 1.668 POI 2 0.011 0.043 0.064 0.005 0.030 0.048 Table 2 Drainage Area Comparison Predevelopment (Acres) Postdevelopment (Acres) POI 1 12.951 12.946 POI 2 0.622 0.627 TOTAL 13.573 13.573 The above table demonstrates that the proposed stormwater detention facilities maintain postdevelopment peak flows at or below each point of interest in comparison to the predevelopment levels. Table 1A illustrates a comparison of the volume of runoff expected in the pre and post development conditions. The storage volumes and operational characteristics for the proposed stormwater basin are summarized in the tables as follows: JN3203 General and Flooding Standards August 2014 Page 5 Brunswick Layover Facility Brunswick, ME

Table 3 Wet Pond Operational Characteristics 2-Year Storm 10-Year Storm 25-Year Storm 100-Yr Storm Inflow to Basin (cfs) 5.35 9.96 12.42 16.29 Total Discharge Basin (cfs) 0.12 3.35 6.55 11.71 Peak Elevation (ft.) 78.00 78.49 78.71 78.99 Storage Volume (c.f.) 20,306 26,137 28,887 32,511 1.14 Urban Impaired Stream Standard The project is not located within an Urban Impaired Stream Watershed. Refer to Attachment F for watershed map. 1.15 Maintenance of Facilities The Applicant will maintain the stormwater management facilities after construction is completed. The general contractor will be responsible for maintenance during construction. The contract documents will require that the contractor designate a person for maintenance of the facilities during construction. Long-term operation/maintenance schedules for the facilities are provided in Attachment E. NNEPRA shall have the right, duty, and obligation to provide for the proper operation and maintenance of the stormwater management system. NNEPRA may contract with such professionals as may be necessary in order to comply with this provision and may rely on the advice of such professionals in carrying out its duty, provided that the operation and maintenance procedures as described in the Basic Standards submission of this application are hereby established as a minimum for compliance with this section. NNEPRA is also responsible to maintain a Stormwater Pollution Prevent Plan (SWPPP) in compliance with the MeDEP Maine Pollutant Discharge Elimination System Multi-Sector General Permit Stormwater Discharge associated with Industrial Activity under which NNEPRA is seeking coverage. 1.16 Conclusions The Stormwater Management Plan for this project is anticipated to mitigate any impacts of development on stormwater runoff. Based on this study s findings, the proposed stormwater management system maintains or reduces postdevelopment peak flows at the points of interest with respect to predevelopment levels, to meet the flooding standard and provides water quality and channel protection to meet the General Standard. JN3203 General and Flooding Standards August 2014 Page 6 Brunswick Layover Facility Brunswick, ME

ATTACHMENT A Pre and Post Development Hydrocad Computations

3 POI2 1 CB SD1 CB SD2 POI1 4 2 Subcat Reach Pond Link Drainage Diagram for 3203-PRE,

3203-PRE Layover Facility Pre-Developemnt Page 2 Area (acres) CN Description (subcatchment-numbers) Area Listing (all nodes) 0.281 35 Brush, Fair, HSG A (3) 7.989 43 Woods/grass comb., Fair, HSG A (1,2,4) 1.842 65 Woods/grass comb., Fair, HSG B (1,2) 2.414 76 Gravel roads, HSG A (1,3,4) 0.749 85 Gravel roads, HSG B (1) 0.298 98 Paved parking & roofs (1) 13.574 TOTAL AREA

3203-PRE Layover Facility Pre-Developemnt Page 3 Area (acres) Soil Goup Subcatchment Numbers 10.685 HSG A 1, 2, 3, 4 2.591 HSG B 1, 2 0.000 HSG C 0.000 HSG D 0.298 Other 1 13.574 TOTAL AREA Soil Listing (all nodes)

3203-PRE Layover Facility Pre-Developemnt Type III 24-hr 2 year Rainfall=3.00" Page 4 Summary for Subcatchment 1: Runoff = 0.76 cfs @ 12.46 hrs, Volume= 0.146 af, Depth> 0.18" Type III 24-hr 2 year Rainfall=3.00" 13,000 98 Paved parking & roofs 57,715 76 Gravel roads, HSG A 32,609 85 Gravel roads, HSG B 252,348 43 Woods/grass comb., Fair, HSG A 61,310 65 Woods/grass comb., Fair, HSG B 416,982 56 Weighted Average 403,982 Pervious Area 13,000 Impervious Area 2.3 100 0.0200 0.74 Sheet Flow, A-B n= 0.023 P2= 3.00" 2.5 206 0.0070 1.35 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 8.6 2,255 0.0070 4.39 52.70 Channel Flow, C-D Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 13.4 2,561 Total Summary for Subcatchment 2: Runoff = 0.02 cfs @ 14.78 hrs, Volume= 0.008 af, Depth> 0.05" Type III 24-hr 2 year Rainfall=3.00" 55,892 43 Woods/grass comb., Fair, HSG A 18,931 65 Woods/grass comb., Fair, HSG B 74,823 49 Weighted Average 74,823 Pervious Area 0.5 30 0.0200 1.05 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.00" 11.0 2,892 0.0070 4.39 52.70 Channel Flow, B-C Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 11.5 2,922 Total

3203-PRE Layover Facility Pre-Developemnt Type III 24-hr 2 year Rainfall=3.00" Page 5 Summary for Subcatchment 3: Runoff = 0.05 cfs @ 12.61 hrs, Volume= 0.011 af, Depth> 0.20" Type III 24-hr 2 year Rainfall=3.00" 14,876 76 Gravel roads, HSG A 12,232 35 Brush, Fair, HSG A 27,108 57 Weighted Average 27,108 Pervious Area 25.7 110 0.0060 0.07 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" Summary for Subcatchment 4: Runoff = 0.14 cfs @ 12.78 hrs, Volume= 0.031 af, Depth> 0.23" Type III 24-hr 2 year Rainfall=3.00" 32,578 76 Gravel roads, HSG A 39,778 43 Woods/grass comb., Fair, HSG A 72,356 58 Weighted Average 72,356 Pervious Area 31.0 150 0.0070 0.08 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 4.0 348 0.0080 1.44 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 3.6 126 0.0070 0.59 Shallow Concentrated Flow, C-D Short Grass Pasture Kv= 7.0 fps 38.6 624 Total Summary for Reach POI1: Inflow Area = 12.951 ac, 2.30% Impervious, Inflow Depth > 0.17" for 2 year event Inflow = 0.84 cfs @ 12.49 hrs, Volume= 0.185 af Outflow = 0.84 cfs @ 12.49 hrs, Volume= 0.185 af, Atten= 0%, Lag= 0.0 min

3203-PRE Layover Facility Pre-Developemnt Type III 24-hr 2 year Rainfall=3.00" Page 6 Summary for Reach POI2: Inflow Area = 0.622 ac, 0.00% Impervious, Inflow Depth > 0.20" for 2 year event Inflow = 0.05 cfs @ 12.61 hrs, Volume= 0.011 af Outflow = 0.05 cfs @ 12.61 hrs, Volume= 0.011 af, Atten= 0%, Lag= 0.0 min Summary for Pond SD1: Inflow Area = 9.573 ac, 3.12% Impervious, Inflow Depth > 0.18" for 2 year event Inflow = 0.76 cfs @ 12.46 hrs, Volume= 0.146 af Outflow = 0.76 cfs @ 12.46 hrs, Volume= 0.146 af, Atten= 0%, Lag= 0.0 min Primary = 0.76 cfs @ 12.46 hrs, Volume= 0.146 af Peak Elev= 73.23' @ 12.52 hrs Device Routing Invert Outlet Devices #1 Primary 72.00' 24.0" x 168.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 71.00' S= 0.0060 '/' Cc= 0.900 n= 0.013 Primary OutFlow Max=0.61 cfs @ 12.46 hrs HW=73.22' TW=73.21' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.61 cfs @ 0.44 fps) Summary for Pond SD2: Inflow Area = 11.234 ac, 2.66% Impervious, Inflow Depth > 0.19" for 2 year event Inflow = 0.84 cfs @ 12.49 hrs, Volume= 0.177 af Outflow = 0.84 cfs @ 12.49 hrs, Volume= 0.177 af, Atten= 0%, Lag= 0.0 min Primary = 0.84 cfs @ 12.49 hrs, Volume= 0.177 af Peak Elev= 73.21' @ 12.49 hrs Device Routing Invert Outlet Devices #1 Primary 73.00' 4.00' W x 4.00' H x 83.0' long Culvert Box, headwall w/3 square edges, Ke= 0.500 Outlet Invert= 72.00' S= 0.0120 '/' Cc= 0.900 n= 0.035 Primary OutFlow Max=0.83 cfs @ 12.49 hrs HW=73.21' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 0.83 cfs @ 1.31 fps)

3203-PRE Layover Facility Pre-Developemnt Type III 24-hr 10 year Rainfall=4.70" Page 7 Summary for Subcatchment 1: Runoff = 6.04 cfs @ 12.23 hrs, Volume= 0.629 af, Depth> 0.79" Type III 24-hr 10 year Rainfall=4.70" 13,000 98 Paved parking & roofs 57,715 76 Gravel roads, HSG A 32,609 85 Gravel roads, HSG B 252,348 43 Woods/grass comb., Fair, HSG A 61,310 65 Woods/grass comb., Fair, HSG B 416,982 56 Weighted Average 403,982 Pervious Area 13,000 Impervious Area 2.3 100 0.0200 0.74 Sheet Flow, A-B n= 0.023 P2= 3.00" 2.5 206 0.0070 1.35 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 8.6 2,255 0.0070 4.39 52.70 Channel Flow, C-D Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 13.4 2,561 Total Summary for Subcatchment 2: Runoff = 0.45 cfs @ 12.31 hrs, Volume= 0.065 af, Depth> 0.45" Type III 24-hr 10 year Rainfall=4.70" 55,892 43 Woods/grass comb., Fair, HSG A 18,931 65 Woods/grass comb., Fair, HSG B 74,823 49 Weighted Average 74,823 Pervious Area 0.5 30 0.0200 1.05 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.00" 11.0 2,892 0.0070 4.39 52.70 Channel Flow, B-C Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 11.5 2,922 Total

3203-PRE Layover Facility Pre-Developemnt Type III 24-hr 10 year Rainfall=4.70" Page 8 Summary for Subcatchment 3: Runoff = 0.34 cfs @ 12.44 hrs, Volume= 0.043 af, Depth> 0.84" Type III 24-hr 10 year Rainfall=4.70" 14,876 76 Gravel roads, HSG A 12,232 35 Brush, Fair, HSG A 27,108 57 Weighted Average 27,108 Pervious Area 25.7 110 0.0060 0.07 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" Summary for Subcatchment 4: Runoff = 0.83 cfs @ 12.63 hrs, Volume= 0.123 af, Depth> 0.89" Type III 24-hr 10 year Rainfall=4.70" 32,578 76 Gravel roads, HSG A 39,778 43 Woods/grass comb., Fair, HSG A 72,356 58 Weighted Average 72,356 Pervious Area 31.0 150 0.0070 0.08 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 4.0 348 0.0080 1.44 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 3.6 126 0.0070 0.59 Shallow Concentrated Flow, C-D Short Grass Pasture Kv= 7.0 fps 38.6 624 Total Summary for Reach POI1: Inflow Area = 12.951 ac, 2.30% Impervious, Inflow Depth > 0.76" for 10 year event Inflow = 6.76 cfs @ 12.24 hrs, Volume= 0.817 af Outflow = 6.76 cfs @ 12.24 hrs, Volume= 0.817 af, Atten= 0%, Lag= 0.0 min

3203-PRE Layover Facility Pre-Developemnt Type III 24-hr 10 year Rainfall=4.70" Page 9 Summary for Reach POI2: Inflow Area = 0.622 ac, 0.00% Impervious, Inflow Depth > 0.84" for 10 year event Inflow = 0.34 cfs @ 12.44 hrs, Volume= 0.043 af Outflow = 0.34 cfs @ 12.44 hrs, Volume= 0.043 af, Atten= 0%, Lag= 0.0 min Summary for Pond SD1: Inflow Area = 9.573 ac, 3.12% Impervious, Inflow Depth > 0.79" for 10 year event Inflow = 6.04 cfs @ 12.23 hrs, Volume= 0.629 af Outflow = 6.04 cfs @ 12.23 hrs, Volume= 0.629 af, Atten= 0%, Lag= 0.0 min Primary = 6.04 cfs @ 12.23 hrs, Volume= 0.629 af Peak Elev= 74.03' @ 12.26 hrs Device Routing Invert Outlet Devices #1 Primary 72.00' 24.0" x 168.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 71.00' S= 0.0060 '/' Cc= 0.900 n= 0.013 Primary OutFlow Max=5.54 cfs @ 12.23 hrs HW=74.00' TW=73.76' (Dynamic Tailwater) 1=Culvert (Outlet Controls 5.54 cfs @ 2.20 fps) Summary for Pond SD2: Inflow Area = 11.234 ac, 2.66% Impervious, Inflow Depth > 0.80" for 10 year event Inflow = 6.32 cfs @ 12.24 hrs, Volume= 0.752 af Outflow = 6.32 cfs @ 12.24 hrs, Volume= 0.752 af, Atten= 0%, Lag= 0.0 min Primary = 6.32 cfs @ 12.24 hrs, Volume= 0.752 af Peak Elev= 73.77' @ 12.24 hrs Device Routing Invert Outlet Devices #1 Primary 73.00' 4.00' W x 4.00' H x 83.0' long Culvert Box, headwall w/3 square edges, Ke= 0.500 Outlet Invert= 72.00' S= 0.0120 '/' Cc= 0.900 n= 0.035 Primary OutFlow Max=6.28 cfs @ 12.24 hrs HW=73.77' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 6.28 cfs @ 2.74 fps)

3203-PRE Layover Facility Pre-Developemnt Type III 24-hr 25 year Rainfall=5.50" Page 10 Summary for Subcatchment 1: Runoff = 9.94 cfs @ 12.21 hrs, Volume= 0.936 af, Depth> 1.17" Type III 24-hr 25 year Rainfall=5.50" 13,000 98 Paved parking & roofs 57,715 76 Gravel roads, HSG A 32,609 85 Gravel roads, HSG B 252,348 43 Woods/grass comb., Fair, HSG A 61,310 65 Woods/grass comb., Fair, HSG B 416,982 56 Weighted Average 403,982 Pervious Area 13,000 Impervious Area 2.3 100 0.0200 0.74 Sheet Flow, A-B n= 0.023 P2= 3.00" 2.5 206 0.0070 1.35 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 8.6 2,255 0.0070 4.39 52.70 Channel Flow, C-D Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 13.4 2,561 Total Summary for Subcatchment 2: Runoff = 0.95 cfs @ 12.22 hrs, Volume= 0.106 af, Depth> 0.74" Type III 24-hr 25 year Rainfall=5.50" 55,892 43 Woods/grass comb., Fair, HSG A 18,931 65 Woods/grass comb., Fair, HSG B 74,823 49 Weighted Average 74,823 Pervious Area 0.5 30 0.0200 1.05 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.00" 11.0 2,892 0.0070 4.39 52.70 Channel Flow, B-C Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 11.5 2,922 Total

3203-PRE Layover Facility Pre-Developemnt Type III 24-hr 25 year Rainfall=5.50" Page 11 Summary for Subcatchment 3: Runoff = 0.54 cfs @ 12.41 hrs, Volume= 0.064 af, Depth> 1.23" Type III 24-hr 25 year Rainfall=5.50" 14,876 76 Gravel roads, HSG A 12,232 35 Brush, Fair, HSG A 27,108 57 Weighted Average 27,108 Pervious Area 25.7 110 0.0060 0.07 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" Summary for Subcatchment 4: Runoff = 1.28 cfs @ 12.60 hrs, Volume= 0.179 af, Depth> 1.29" Type III 24-hr 25 year Rainfall=5.50" 32,578 76 Gravel roads, HSG A 39,778 43 Woods/grass comb., Fair, HSG A 72,356 58 Weighted Average 72,356 Pervious Area 31.0 150 0.0070 0.08 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 4.0 348 0.0080 1.44 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 3.6 126 0.0070 0.59 Shallow Concentrated Flow, C-D Short Grass Pasture Kv= 7.0 fps 38.6 624 Total Summary for Reach POI1: Inflow Area = 12.951 ac, 2.30% Impervious, Inflow Depth > 1.13" for 25 year event Inflow = 11.37 cfs @ 12.22 hrs, Volume= 1.221 af Outflow = 11.37 cfs @ 12.22 hrs, Volume= 1.221 af, Atten= 0%, Lag= 0.0 min

3203-PRE Layover Facility Pre-Developemnt Type III 24-hr 25 year Rainfall=5.50" Page 12 Summary for Reach POI2: Inflow Area = 0.622 ac, 0.00% Impervious, Inflow Depth > 1.23" for 25 year event Inflow = 0.54 cfs @ 12.41 hrs, Volume= 0.064 af Outflow = 0.54 cfs @ 12.41 hrs, Volume= 0.064 af, Atten= 0%, Lag= 0.0 min Summary for Pond SD1: Inflow Area = 9.573 ac, 3.12% Impervious, Inflow Depth > 1.17" for 25 year event Inflow = 9.94 cfs @ 12.21 hrs, Volume= 0.936 af Outflow = 9.94 cfs @ 12.21 hrs, Volume= 0.936 af, Atten= 0%, Lag= 0.0 min Primary = 9.94 cfs @ 12.21 hrs, Volume= 0.936 af Peak Elev= 74.55' @ 12.24 hrs Device Routing Invert Outlet Devices #1 Primary 72.00' 24.0" x 168.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 71.00' S= 0.0060 '/' Cc= 0.900 n= 0.013 Primary OutFlow Max=9.27 cfs @ 12.21 hrs HW=74.52' TW=74.06' (Dynamic Tailwater) 1=Culvert (Outlet Controls 9.27 cfs @ 3.02 fps) Summary for Pond SD2: Inflow Area = 11.234 ac, 2.66% Impervious, Inflow Depth > 1.19" for 25 year event Inflow = 10.41 cfs @ 12.22 hrs, Volume= 1.115 af Outflow = 10.41 cfs @ 12.22 hrs, Volume= 1.115 af, Atten= 0%, Lag= 0.0 min Primary = 10.41 cfs @ 12.22 hrs, Volume= 1.115 af Peak Elev= 74.07' @ 12.22 hrs Device Routing Invert Outlet Devices #1 Primary 73.00' 4.00' W x 4.00' H x 83.0' long Culvert Box, headwall w/3 square edges, Ke= 0.500 Outlet Invert= 72.00' S= 0.0120 '/' Cc= 0.900 n= 0.035 Primary OutFlow Max=10.26 cfs @ 12.22 hrs HW=74.06' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 10.26 cfs @ 3.23 fps)

Layover Facility Pre-Developemnt 3203-PRE Type III 24-hr 100 year Rainfall=6.70" Page 13 Summary for Subcatchment 1: Runoff = 16.52 cfs @ 12.21 hrs, Volume= 1.464 af, Depth> 1.84" Type III 24-hr 100 year Rainfall=6.70" 13,000 98 Paved parking & roofs 57,715 76 Gravel roads, HSG A 32,609 85 Gravel roads, HSG B 252,348 43 Woods/grass comb., Fair, HSG A 61,310 65 Woods/grass comb., Fair, HSG B 416,982 56 Weighted Average 403,982 Pervious Area 13,000 Impervious Area 2.3 100 0.0200 0.74 Sheet Flow, A-B n= 0.023 P2= 3.00" 2.5 206 0.0070 1.35 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 8.6 2,255 0.0070 4.39 52.70 Channel Flow, C-D Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 13.4 2,561 Total Summary for Subcatchment 2: Runoff = 1.93 cfs @ 12.19 hrs, Volume= 0.181 af, Depth> 1.27" Type III 24-hr 100 year Rainfall=6.70" 55,892 43 Woods/grass comb., Fair, HSG A 18,931 65 Woods/grass comb., Fair, HSG B 74,823 49 Weighted Average 74,823 Pervious Area 0.5 30 0.0200 1.05 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.00" 11.0 2,892 0.0070 4.39 52.70 Channel Flow, B-C Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 11.5 2,922 Total

Layover Facility Pre-Developemnt 3203-PRE Type III 24-hr 100 year Rainfall=6.70" Page 14 Summary for Subcatchment 3: Runoff = 0.88 cfs @ 12.39 hrs, Volume= 0.099 af, Depth> 1.91" Type III 24-hr 100 year Rainfall=6.70" 14,876 76 Gravel roads, HSG A 12,232 35 Brush, Fair, HSG A 27,108 57 Weighted Average 27,108 Pervious Area 25.7 110 0.0060 0.07 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" Summary for Subcatchment 4: Runoff = 2.04 cfs @ 12.58 hrs, Volume= 0.275 af, Depth> 1.99" Type III 24-hr 100 year Rainfall=6.70" 32,578 76 Gravel roads, HSG A 39,778 43 Woods/grass comb., Fair, HSG A 72,356 58 Weighted Average 72,356 Pervious Area 31.0 150 0.0070 0.08 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 4.0 348 0.0080 1.44 Shallow Concentrated Flow, B-C Unpaved Kv= 16.1 fps 3.6 126 0.0070 0.59 Shallow Concentrated Flow, C-D Short Grass Pasture Kv= 7.0 fps 38.6 624 Total Summary for Reach POI1: Inflow Area = 12.951 ac, 2.30% Impervious, Inflow Depth > 1.78" for 100 year event Inflow = 19.29 cfs @ 12.21 hrs, Volume= 1.920 af Outflow = 19.29 cfs @ 12.21 hrs, Volume= 1.920 af, Atten= 0%, Lag= 0.0 min

Layover Facility Pre-Developemnt 3203-PRE Type III 24-hr 100 year Rainfall=6.70" Page 15 Summary for Reach POI2: Inflow Area = 0.622 ac, 0.00% Impervious, Inflow Depth > 1.91" for 100 year event Inflow = 0.88 cfs @ 12.39 hrs, Volume= 0.099 af Outflow = 0.88 cfs @ 12.39 hrs, Volume= 0.099 af, Atten= 0%, Lag= 0.0 min Summary for Pond SD1: Inflow Area = 9.573 ac, 3.12% Impervious, Inflow Depth > 1.84" for 100 year event Inflow = 16.52 cfs @ 12.21 hrs, Volume= 1.464 af Outflow = 16.52 cfs @ 12.21 hrs, Volume= 1.464 af, Atten= 0%, Lag= 0.0 min Primary = 16.52 cfs @ 12.21 hrs, Volume= 1.464 af Peak Elev= 76.00' @ 12.22 hrs Device Routing Invert Outlet Devices #1 Primary 72.00' 24.0" x 168.0' long Culvert RCP, sq.cut end projecting, Ke= 0.500 Outlet Invert= 71.00' S= 0.0060 '/' Cc= 0.900 n= 0.013 Primary OutFlow Max=16.01 cfs @ 12.21 hrs HW=75.96' TW=74.51' (Dynamic Tailwater) 1=Culvert (Outlet Controls 16.01 cfs @ 5.10 fps) Summary for Pond SD2: Inflow Area = 11.234 ac, 2.66% Impervious, Inflow Depth > 1.86" for 100 year event Inflow = 17.37 cfs @ 12.21 hrs, Volume= 1.739 af Outflow = 17.37 cfs @ 12.21 hrs, Volume= 1.739 af, Atten= 0%, Lag= 0.0 min Primary = 17.37 cfs @ 12.21 hrs, Volume= 1.739 af Peak Elev= 74.51' @ 12.21 hrs Device Routing Invert Outlet Devices #1 Primary 73.00' 4.00' W x 4.00' H x 83.0' long Culvert Box, headwall w/3 square edges, Ke= 0.500 Outlet Invert= 72.00' S= 0.0120 '/' Cc= 0.900 n= 0.035 Primary OutFlow Max=17.20 cfs @ 12.21 hrs HW=74.50' TW=0.00' (Dynamic Tailwater) 1=Culvert (Barrel Controls 17.20 cfs @ 3.81 fps)

7 2 6 CB DMH2 CB15 1 CB SD7 CB CB1 CB DMH1 CB DMH3 5 POI2 CB CB9 1A WP1 POI1 3 1A-2 8 4 BACK ROOF AREA Subcat Reach Pond Link Drainage Diagram for 3203-POST,

3203-POST Layover Facility Post Development Page 2 Area (acres) CN Description (subcatchment-numbers) Area Listing (all nodes) 4.312 39 >75% Grass cover, Good, HSG A (1,2,5,6,7,8) 1.283 43 Woods/grass comb., Fair, HSG A (4) 0.308 61 >75% Grass cover, Good, HSG B (1A,3) 0.435 65 Woods/grass comb., Fair, HSG B (4) 3.541 76 Gravel roads, HSG A (1,5,6,7,8) 1.190 85 Gravel roads, HSG B (3,6) 2.332 98 Paved parking & roofs (1,1A,1A-2,2,5,8) 0.173 98 Water Surface (8) 13.574 TOTAL AREA

3203-POST Layover Facility Post Development Page 3 Area (acres) Soil Goup Subcatchment Numbers 9.136 HSG A 1, 2, 4, 5, 6, 7, 8 1.933 HSG B 1A, 3, 4, 6 0.000 HSG C 0.000 HSG D 2.504 Other 1, 1A, 1A-2, 2, 5, 8 13.574 TOTAL AREA Soil Listing (all nodes)

3203-POST Layover Facility Post Development Type III 24-hr 2 year Rainfall=3.00" Page 4 Summary for Subcatchment 1: Runoff = 0.57 cfs @ 12.59 hrs, Volume= 0.094 af, Depth> 0.34" Type III 24-hr 2 year Rainfall=3.00" 85,716 76 Gravel roads, HSG A 56,324 39 >75% Grass cover, Good, HSG A 1,876 98 Paved parking & roofs 143,916 62 Weighted Average 142,040 Pervious Area 1,876 Impervious Area 8.5 50 0.0200 0.10 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 22.5 1,430 0.0050 1.06 Shallow Concentrated Flow, B-C Grassed Waterway Kv= 15.0 fps 31.0 1,480 Total Summary for Subcatchment 1A: Runoff = 3.41 cfs @ 12.09 hrs, Volume= 0.252 af, Depth> 2.41" Type III 24-hr 2 year Rainfall=3.00" 2,505 61 >75% Grass cover, Good, HSG B 52,272 98 Paved parking & roofs 54,777 96 Weighted Average 2,505 Pervious Area 52,272 Impervious Area 3.4 18 0.0100 0.09 Sheet Flow, A-B Grass: Short n= 0.150 P2= 3.00" 2.9 614 0.0020 3.49 10.96 Circular Channel (pipe), B-C Diam= 24.0" Area= 3.1 sf Perim= 6.3' r= 0.50' n= 0.012 6.3 632 Total

3203-POST Layover Facility Post Development Type III 24-hr 2 year Rainfall=3.00" Page 5 Summary for Subcatchment 1A-2: BACK ROOF AREA Runoff = 1.53 cfs @ 12.09 hrs, Volume= 0.116 af, Depth> 2.59" Type III 24-hr 2 year Rainfall=3.00" 23,459 98 Paved parking & roofs 23,459 Impervious Area 6.0 Direct Entry, Summary for Subcatchment 2: Runoff = 0.01 cfs @ 16.08 hrs, Volume= 0.005 af, Depth> 0.03" Type III 24-hr 2 year Rainfall=3.00" 13,000 98 Paved parking & roofs 78,499 39 >75% Grass cover, Good, HSG A 91,499 47 Weighted Average 78,499 Pervious Area 13,000 Impervious Area 26.9 150 0.0100 0.09 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 29.9 2,255 0.0070 1.25 Shallow Concentrated Flow, B-C Grassed Waterway Kv= 15.0 fps 56.8 2,405 Total Summary for Subcatchment 3: Runoff = 0.72 cfs @ 12.36 hrs, Volume= 0.078 af, Depth> 1.03" Type III 24-hr 2 year Rainfall=3.00"

3203-POST Layover Facility Post Development Type III 24-hr 2 year Rainfall=3.00" Page 6 28,572 85 Gravel roads, HSG B 10,924 61 >75% Grass cover, Good, HSG B 39,496 78 Weighted Average 39,496 Pervious Area 5.4 150 0.0050 0.46 Sheet Flow, A-B n= 0.023 P2= 3.00" 18.7 554 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 24.1 704 Total Summary for Subcatchment 4: Runoff = 0.02 cfs @ 14.78 hrs, Volume= 0.008 af, Depth> 0.05" Type III 24-hr 2 year Rainfall=3.00" 55,892 43 Woods/grass comb., Fair, HSG A 18,931 65 Woods/grass comb., Fair, HSG B 74,823 49 Weighted Average 74,823 Pervious Area 0.5 30 0.0200 1.05 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.00" 11.0 2,892 0.0070 4.39 52.70 Channel Flow, B-C Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 11.5 2,922 Total Summary for Subcatchment 5: Runoff = 0.01 cfs @ 12.96 hrs, Volume= 0.005 af, Depth> 0.10" Type III 24-hr 2 year Rainfall=3.00" 1,502 98 Paved parking & roofs 7,082 76 Gravel roads, HSG A 18,749 39 >75% Grass cover, Good, HSG A 27,333 52 Weighted Average 25,831 Pervious Area 1,502 Impervious Area

3203-POST Layover Facility Post Development Type III 24-hr 2 year Rainfall=3.00" Page 7 25.7 110 0.0060 0.07 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" Summary for Subcatchment 6: Runoff = 0.82 cfs @ 12.44 hrs, Volume= 0.097 af, Depth> 1.03" Type III 24-hr 2 year Rainfall=3.00" 2,660 39 >75% Grass cover, Good, HSG A 23,270 76 Gravel roads, HSG A 23,270 85 Gravel roads, HSG B 49,200 78 Weighted Average 49,200 Pervious Area 6.1 125 0.0060 0.34 Sheet Flow, A-B n= 0.035 P2= 3.00" 23.3 692 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 29.4 817 Total Summary for Subcatchment 7: Runoff = 0.29 cfs @ 12.52 hrs, Volume= 0.038 af, Depth> 0.68" Type III 24-hr 2 year Rainfall=3.00" 4,294 39 >75% Grass cover, Good, HSG A 25,349 76 Gravel roads, HSG A 29,643 71 Weighted Average 29,643 Pervious Area

3203-POST Layover Facility Post Development Type III 24-hr 2 year Rainfall=3.00" Page 8 26.9 150 0.0100 0.09 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 4.9 146 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 0.9 187 0.0050 3.47 2.73 Circular Channel (pipe), C-D Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 32.7 483 Total Summary for Subcatchment 8: Runoff = 0.38 cfs @ 12.38 hrs, Volume= 0.048 af, Depth> 0.44" Type III 24-hr 2 year Rainfall=3.00" 27,306 39 >75% Grass cover, Good, HSG A 12,833 76 Gravel roads, HSG A 7,526 98 Water Surface 9,455 98 Paved parking & roofs 57,120 65 Weighted Average 40,139 Pervious Area 16,981 Impervious Area 14.7 100 0.0200 0.11 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 6.1 256 0.0100 0.70 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 20.8 356 Total Summary for Reach POI1: Inflow Area = 12.946 ac, 19.08% Impervious, Inflow Depth > 0.25" for 2 year event Inflow = 0.81 cfs @ 12.56 hrs, Volume= 0.270 af Outflow = 0.81 cfs @ 12.56 hrs, Volume= 0.270 af, Atten= 0%, Lag= 0.0 min Summary for Reach POI2: Inflow Area = 0.627 ac, 5.50% Impervious, Inflow Depth > 0.10" for 2 year event Inflow = 0.01 cfs @ 12.96 hrs, Volume= 0.005 af Outflow = 0.01 cfs @ 12.96 hrs, Volume= 0.005 af, Atten= 0%, Lag= 0.0 min

3203-POST Layover Facility Post Development Type III 24-hr 2 year Rainfall=3.00" Page 9 Summary for Pond CB1: Inflow Area = 6.007 ac, 29.66% Impervious, Inflow Depth > 1.08" for 2 year event Inflow = 5.27 cfs @ 12.09 hrs, Volume= 0.540 af Outflow = 5.27 cfs @ 12.09 hrs, Volume= 0.540 af, Atten= 0%, Lag= 0.0 min Primary = 5.27 cfs @ 12.09 hrs, Volume= 0.540 af Peak Elev= 78.00' @ 20.00 hrs Device Routing Invert Outlet Devices #1 Primary 76.35' 30.0" x 280.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 76.06' S= 0.0010 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=4.76 cfs @ 12.09 hrs HW=77.74' TW=77.31' (Dynamic Tailwater) 1=Culvert (Outlet Controls 4.76 cfs @ 2.46 fps) Summary for Pond CB15: Inflow Area = 1.129 ac, 0.00% Impervious, Inflow Depth > 1.03" for 2 year event Inflow = 0.82 cfs @ 12.44 hrs, Volume= 0.097 af Outflow = 0.43 cfs @ 12.85 hrs, Volume= 0.097 af, Atten= 48%, Lag= 25.1 min Primary = 0.43 cfs @ 12.85 hrs, Volume= 0.097 af Secondary = 0.00 cfs @ 5.00 hrs, Volume= 0.000 af Peak Elev= 80.07' @ 12.85 hrs Surf.Area= 804 sf Storage= 672 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 9.6 min ( 838.8-829.3 ) Volume Invert Avail.Storage Storage Description #1 76.70' 1,608 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 76.70 4 0 0 77.00 4 1 1 78.00 4 4 5 78.90 4 4 9 79.00 404 20 29 80.00 775 590 619 81.00 1,203 989 1,608

3203-POST Layover Facility Post Development Type III 24-hr 2 year Rainfall=3.00" Page 10 Device Routing Invert Outlet Devices #1 Primary 76.70' 3.0" Vert. Orifice/Grate C= 0.600 #2 Secondary 80.10' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 #3 Device 2 76.60' 12.0" x 286.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 75.10' S= 0.0052 '/' Cc= 0.900 n= 0.012 #4 Secondary 80.80' 10.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=0.43 cfs @ 12.85 hrs HW=80.07' TW=73.37' (Dynamic Tailwater) 1=Orifice/Grate (Orifice Controls 0.43 cfs @ 8.67 fps) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=76.70' TW=73.07' (Dynamic Tailwater) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Culvert ( Controls 0.00 cfs) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond CB9: Inflow Area = 1.445 ac, 37.26% Impervious, Inflow Depth > 1.61" for 2 year event Inflow = 1.84 cfs @ 12.10 hrs, Volume= 0.194 af Outflow = 1.84 cfs @ 12.10 hrs, Volume= 0.194 af, Atten= 0%, Lag= 0.0 min Primary = 1.84 cfs @ 12.10 hrs, Volume= 0.194 af Peak Elev= 80.71' @ 12.10 hrs Device Routing Invert Outlet Devices #1 Primary 79.72' 12.0" x 76.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 79.50' S= 0.0029 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=1.83 cfs @ 12.10 hrs HW=80.71' TW=79.78' (Dynamic Tailwater) 1=Culvert (Barrel Controls 1.83 cfs @ 2.93 fps) Summary for Pond DMH1: Inflow Area = 6.007 ac, 29.66% Impervious, Inflow Depth > 1.08" for 2 year event Inflow = 5.27 cfs @ 12.09 hrs, Volume= 0.540 af Outflow = 5.27 cfs @ 12.09 hrs, Volume= 0.540 af, Atten= 0%, Lag= 0.0 min Primary = 5.27 cfs @ 12.09 hrs, Volume= 0.540 af Peak Elev= 78.00' @ 20.00 hrs Device Routing Invert Outlet Devices #1 Primary 76.06' 30.0" x 60.7' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 76.00' S= 0.0010 '/' Cc= 0.900 n= 0.012

3203-POST Layover Facility Post Development Type III 24-hr 2 year Rainfall=3.00" Page 11 Primary OutFlow Max=5.20 cfs @ 12.09 hrs HW=77.31' TW=76.63' (Dynamic Tailwater) 1=Culvert (Barrel Controls 5.20 cfs @ 3.08 fps) Summary for Pond DMH2: Inflow Area = 2.101 ac, 14.21% Impervious, Inflow Depth > 0.03" for 2 year event Inflow = 0.01 cfs @ 16.08 hrs, Volume= 0.005 af Outflow = 0.01 cfs @ 16.08 hrs, Volume= 0.005 af, Atten= 0%, Lag= 0.0 min Primary = 0.01 cfs @ 16.08 hrs, Volume= 0.005 af Peak Elev= 74.06' @ 16.08 hrs Device Routing Invert Outlet Devices #1 Primary 74.00' 24.0" x 104.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 73.50' S= 0.0048 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=0.01 cfs @ 16.08 hrs HW=74.06' TW=73.21' (Dynamic Tailwater) 1=Culvert (Barrel Controls 0.01 cfs @ 0.77 fps) Summary for Pond DMH3: Inflow Area = 11.228 ac, 22.00% Impervious, Inflow Depth > 0.28" for 2 year event Inflow = 0.81 cfs @ 12.56 hrs, Volume= 0.262 af Outflow = 0.81 cfs @ 12.56 hrs, Volume= 0.262 af, Atten= 0%, Lag= 0.0 min Primary = 0.81 cfs @ 12.56 hrs, Volume= 0.262 af Peak Elev= 73.39' @ 12.56 hrs Device Routing Invert Outlet Devices #1 Primary 73.00' 30.0" x 74.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 72.00' S= 0.0135 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=0.81 cfs @ 12.56 hrs HW=73.39' TW=0.00' (Dynamic Tailwater) 1=Culvert (Inlet Controls 0.81 cfs @ 1.67 fps) Summary for Pond SD7: Inflow Area = 4.749 ac, 12.25% Impervious, Inflow Depth > 0.73" for 2 year event Inflow = 1.86 cfs @ 12.10 hrs, Volume= 0.288 af Outflow = 1.86 cfs @ 12.10 hrs, Volume= 0.288 af, Atten= 0%, Lag= 0.0 min Primary = 1.86 cfs @ 12.10 hrs, Volume= 0.288 af Peak Elev= 79.78' @ 12.11 hrs Device Routing Invert Outlet Devices #1 Primary 79.00' 18.0" x 735.0' long Culvert CPP, projecting, no headwall, Ke= 0.900

3203-POST Layover Facility Post Development Type III 24-hr 2 year Rainfall=3.00" Page 12 Outlet Invert= 76.62' S= 0.0032 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=1.80 cfs @ 12.10 hrs HW=79.78' TW=77.75' (Dynamic Tailwater) 1=Culvert (Outlet Controls 1.80 cfs @ 2.82 fps) Summary for Pond WP1: Inflow Area = 7.318 ac, 29.67% Impervious, Inflow Depth > 0.97" for 2 year event Inflow = 5.35 cfs @ 12.10 hrs, Volume= 0.589 af Outflow = 0.12 cfs @ 20.00 hrs, Volume= 0.122 af, Atten= 98%, Lag= 474.2 min Primary = 0.12 cfs @ 20.00 hrs, Volume= 0.122 af Peak Elev= 78.00' @ 20.00 hrs Surf.Area= 11,676 sf Storage= 20,306 cf Plug-Flow detention time= 190.8 min calculated for 0.122 af (21% of inflow) Center-of-Mass det. time= 24.9 min ( 811.8-786.9 ) Volume Invert Avail.Storage Storage Description #1 76.00' 46,429 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 76.00 8,384 375.0 0 0 8,384 77.00 10,288 451.0 9,320 9,320 13,397 78.00 11,674 462.0 10,974 20,293 14,317 79.00 13,092 478.0 12,376 32,670 15,603 80.00 14,437 490.0 13,759 46,429 16,646 Device Routing Invert Outlet Devices #1 Primary 73.00' 24.0" x 19.3' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 72.80' S= 0.0104 '/' Cc= 0.900 n= 0.012 #2 Device 1 78.10' 4.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height #3 Device 1 79.00' 21.1' long x 0.7' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 Coef. (English) 2.76 2.82 2.93 3.09 3.18 3.22 3.27 3.30 3.32 3.31 3.32 #4 Device 1 73.67' 1.5" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.12 cfs @ 20.00 hrs HW=78.00' TW=0.00' (Dynamic Tailwater) 1=Culvert (Passes 0.12 cfs of 23.89 cfs potential flow) 2=Sharp-Crested Rectangular Weir ( Controls 0.00 cfs) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 4=Orifice/Grate (Orifice Controls 0.12 cfs @ 9.95 fps)

3203-POST Layover Facility Post Development Type III 24-hr 10 year Rainfall=4.70" Page 13 Summary for Subcatchment 1: Runoff = 2.45 cfs @ 12.49 hrs, Volume= 0.309 af, Depth> 1.12" Type III 24-hr 10 year Rainfall=4.70" 85,716 76 Gravel roads, HSG A 56,324 39 >75% Grass cover, Good, HSG A 1,876 98 Paved parking & roofs 143,916 62 Weighted Average 142,040 Pervious Area 1,876 Impervious Area 8.5 50 0.0200 0.10 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 22.5 1,430 0.0050 1.06 Shallow Concentrated Flow, B-C Grassed Waterway Kv= 15.0 fps 31.0 1,480 Total Summary for Subcatchment 1A: Runoff = 5.51 cfs @ 12.09 hrs, Volume= 0.417 af, Depth> 3.98" Type III 24-hr 10 year Rainfall=4.70" 2,505 61 >75% Grass cover, Good, HSG B 52,272 98 Paved parking & roofs 54,777 96 Weighted Average 2,505 Pervious Area 52,272 Impervious Area 3.4 18 0.0100 0.09 Sheet Flow, A-B Grass: Short n= 0.150 P2= 3.00" 2.9 614 0.0020 3.49 10.96 Circular Channel (pipe), B-C Diam= 24.0" Area= 3.1 sf Perim= 6.3' r= 0.50' n= 0.012 6.3 632 Total

3203-POST Layover Facility Post Development Type III 24-hr 10 year Rainfall=4.70" Page 14 Summary for Subcatchment 1A-2: BACK ROOF AREA Runoff = 2.42 cfs @ 12.09 hrs, Volume= 0.186 af, Depth> 4.15" Type III 24-hr 10 year Rainfall=4.70" 23,459 98 Paved parking & roofs 23,459 Impervious Area 6.0 Direct Entry, Summary for Subcatchment 2: Runoff = 0.23 cfs @ 13.07 hrs, Volume= 0.062 af, Depth> 0.36" Type III 24-hr 10 year Rainfall=4.70" 13,000 98 Paved parking & roofs 78,499 39 >75% Grass cover, Good, HSG A 91,499 47 Weighted Average 78,499 Pervious Area 13,000 Impervious Area 26.9 150 0.0100 0.09 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 29.9 2,255 0.0070 1.25 Shallow Concentrated Flow, B-C Grassed Waterway Kv= 15.0 fps 56.8 2,405 Total Summary for Subcatchment 3: Runoff = 1.62 cfs @ 12.34 hrs, Volume= 0.172 af, Depth> 2.27" Type III 24-hr 10 year Rainfall=4.70"

3203-POST Layover Facility Post Development Type III 24-hr 10 year Rainfall=4.70" Page 15 28,572 85 Gravel roads, HSG B 10,924 61 >75% Grass cover, Good, HSG B 39,496 78 Weighted Average 39,496 Pervious Area 5.4 150 0.0050 0.46 Sheet Flow, A-B n= 0.023 P2= 3.00" 18.7 554 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 24.1 704 Total Summary for Subcatchment 4: Runoff = 0.45 cfs @ 12.31 hrs, Volume= 0.065 af, Depth> 0.45" Type III 24-hr 10 year Rainfall=4.70" 55,892 43 Woods/grass comb., Fair, HSG A 18,931 65 Woods/grass comb., Fair, HSG B 74,823 49 Weighted Average 74,823 Pervious Area 0.5 30 0.0200 1.05 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.00" 11.0 2,892 0.0070 4.39 52.70 Channel Flow, B-C Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 11.5 2,922 Total Summary for Subcatchment 5: Runoff = 0.21 cfs @ 12.49 hrs, Volume= 0.030 af, Depth> 0.58" Type III 24-hr 10 year Rainfall=4.70" 1,502 98 Paved parking & roofs 7,082 76 Gravel roads, HSG A 18,749 39 >75% Grass cover, Good, HSG A 27,333 52 Weighted Average 25,831 Pervious Area 1,502 Impervious Area

3203-POST Layover Facility Post Development Type III 24-hr 10 year Rainfall=4.70" Page 16 25.7 110 0.0060 0.07 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" Summary for Subcatchment 6: Runoff = 1.85 cfs @ 12.41 hrs, Volume= 0.214 af, Depth> 2.27" Type III 24-hr 10 year Rainfall=4.70" 2,660 39 >75% Grass cover, Good, HSG A 23,270 76 Gravel roads, HSG A 23,270 85 Gravel roads, HSG B 49,200 78 Weighted Average 49,200 Pervious Area 6.1 125 0.0060 0.34 Sheet Flow, A-B n= 0.035 P2= 3.00" 23.3 692 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 29.4 817 Total Summary for Subcatchment 7: Runoff = 0.80 cfs @ 12.48 hrs, Volume= 0.098 af, Depth> 1.72" Type III 24-hr 10 year Rainfall=4.70" 4,294 39 >75% Grass cover, Good, HSG A 25,349 76 Gravel roads, HSG A 29,643 71 Weighted Average 29,643 Pervious Area

3203-POST Layover Facility Post Development Type III 24-hr 10 year Rainfall=4.70" Page 17 26.9 150 0.0100 0.09 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 4.9 146 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 0.9 187 0.0050 3.47 2.73 Circular Channel (pipe), C-D Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 32.7 483 Total Summary for Subcatchment 8: Runoff = 1.38 cfs @ 12.32 hrs, Volume= 0.144 af, Depth> 1.32" Type III 24-hr 10 year Rainfall=4.70" 27,306 39 >75% Grass cover, Good, HSG A 12,833 76 Gravel roads, HSG A 7,526 98 Water Surface 9,455 98 Paved parking & roofs 57,120 65 Weighted Average 40,139 Pervious Area 16,981 Impervious Area 14.7 100 0.0200 0.11 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 6.1 256 0.0100 0.70 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 20.8 356 Total Summary for Reach POI1: Inflow Area = 12.946 ac, 19.08% Impervious, Inflow Depth > 1.07" for 10 year event Inflow = 5.57 cfs @ 12.74 hrs, Volume= 1.154 af Outflow = 5.57 cfs @ 12.74 hrs, Volume= 1.154 af, Atten= 0%, Lag= 0.0 min Summary for Reach POI2: Inflow Area = 0.627 ac, 5.50% Impervious, Inflow Depth > 0.58" for 10 year event Inflow = 0.21 cfs @ 12.49 hrs, Volume= 0.030 af Outflow = 0.21 cfs @ 12.49 hrs, Volume= 0.030 af, Atten= 0%, Lag= 0.0 min

3203-POST Layover Facility Post Development Type III 24-hr 10 year Rainfall=4.70" Page 18 Summary for Pond CB1: Inflow Area = 6.007 ac, 29.66% Impervious, Inflow Depth > 2.16" for 10 year event Inflow = 9.31 cfs @ 12.10 hrs, Volume= 1.084 af Outflow = 9.31 cfs @ 12.10 hrs, Volume= 1.084 af, Atten= 0%, Lag= 0.0 min Primary = 9.31 cfs @ 12.10 hrs, Volume= 1.084 af Peak Elev= 78.54' @ 12.85 hrs Device Routing Invert Outlet Devices #1 Primary 76.35' 30.0" x 280.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 76.06' S= 0.0010 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=8.41 cfs @ 12.10 hrs HW=78.27' TW=77.78' (Dynamic Tailwater) 1=Culvert (Outlet Controls 8.41 cfs @ 2.87 fps) Summary for Pond CB15: Inflow Area = 1.129 ac, 0.00% Impervious, Inflow Depth > 2.27" for 10 year event Inflow = 1.85 cfs @ 12.41 hrs, Volume= 0.214 af Outflow = 1.68 cfs @ 12.54 hrs, Volume= 0.214 af, Atten= 9%, Lag= 7.6 min Primary = 0.45 cfs @ 12.54 hrs, Volume= 0.159 af Secondary = 1.23 cfs @ 12.54 hrs, Volume= 0.055 af Peak Elev= 80.46' @ 12.54 hrs Surf.Area= 973 sf Storage= 1,024 cf Plug-Flow detention time= 9.7 min calculated for 0.213 af (100% of inflow) Center-of-Mass det. time= 9.6 min ( 821.6-812.0 ) Volume Invert Avail.Storage Storage Description #1 76.70' 1,608 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 76.70 4 0 0 77.00 4 1 1 78.00 4 4 5 78.90 4 4 9 79.00 404 20 29 80.00 775 590 619 81.00 1,203 989 1,608

3203-POST Layover Facility Post Development Type III 24-hr 10 year Rainfall=4.70" Page 19 Device Routing Invert Outlet Devices #1 Primary 76.70' 3.0" Vert. Orifice/Grate C= 0.600 #2 Secondary 80.10' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 #3 Device 2 76.60' 12.0" x 286.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 75.10' S= 0.0052 '/' Cc= 0.900 n= 0.012 #4 Secondary 80.80' 10.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=0.45 cfs @ 12.54 hrs HW=80.46' TW=73.91' (Dynamic Tailwater) 1=Orifice/Grate (Orifice Controls 0.45 cfs @ 9.18 fps) Secondary OutFlow Max=1.23 cfs @ 12.54 hrs HW=80.46' TW=73.91' (Dynamic Tailwater) 2=Orifice/Grate (Passes 1.23 cfs of 5.69 cfs potential flow) 3=Culvert (Outlet Controls 1.23 cfs @ 1.56 fps) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond CB9: Inflow Area = 1.445 ac, 37.26% Impervious, Inflow Depth > 2.97" for 10 year event Inflow = 3.22 cfs @ 12.10 hrs, Volume= 0.358 af Outflow = 3.22 cfs @ 12.10 hrs, Volume= 0.358 af, Atten= 0%, Lag= 0.0 min Primary = 3.22 cfs @ 12.10 hrs, Volume= 0.358 af Peak Elev= 81.52' @ 12.10 hrs Device Routing Invert Outlet Devices #1 Primary 79.72' 12.0" x 76.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 79.50' S= 0.0029 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=3.21 cfs @ 12.10 hrs HW=81.52' TW=80.21' (Dynamic Tailwater) 1=Culvert (Barrel Controls 3.21 cfs @ 4.08 fps) Summary for Pond DMH1: Inflow Area = 6.007 ac, 29.66% Impervious, Inflow Depth > 2.16" for 10 year event Inflow = 9.31 cfs @ 12.10 hrs, Volume= 1.084 af Outflow = 9.31 cfs @ 12.10 hrs, Volume= 1.084 af, Atten= 0%, Lag= 0.0 min Primary = 9.31 cfs @ 12.10 hrs, Volume= 1.084 af Peak Elev= 78.51' @ 12.86 hrs Device Routing Invert Outlet Devices #1 Primary 76.06' 30.0" x 60.7' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 76.00' S= 0.0010 '/' Cc= 0.900 n= 0.012

3203-POST Layover Facility Post Development Type III 24-hr 10 year Rainfall=4.70" Page 20 Primary OutFlow Max=9.28 cfs @ 12.10 hrs HW=77.78' TW=77.26' (Dynamic Tailwater) 1=Culvert (Barrel Controls 9.28 cfs @ 3.65 fps) Summary for Pond DMH2: Inflow Area = 2.101 ac, 14.21% Impervious, Inflow Depth > 0.36" for 10 year event Inflow = 0.23 cfs @ 13.07 hrs, Volume= 0.062 af Outflow = 0.23 cfs @ 13.07 hrs, Volume= 0.062 af, Atten= 0%, Lag= 0.0 min Primary = 0.23 cfs @ 13.07 hrs, Volume= 0.062 af Peak Elev= 74.27' @ 12.91 hrs Device Routing Invert Outlet Devices #1 Primary 74.00' 24.0" x 104.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 73.50' S= 0.0048 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=0.24 cfs @ 13.07 hrs HW=74.26' TW=73.91' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.24 cfs @ 1.56 fps) Summary for Pond DMH3: Inflow Area = 11.228 ac, 22.00% Impervious, Inflow Depth > 1.16" for 10 year event Inflow = 5.37 cfs @ 12.75 hrs, Volume= 1.090 af Outflow = 5.37 cfs @ 12.75 hrs, Volume= 1.090 af, Atten= 0%, Lag= 0.0 min Primary = 5.37 cfs @ 12.75 hrs, Volume= 1.090 af Peak Elev= 74.05' @ 12.75 hrs Device Routing Invert Outlet Devices #1 Primary 73.00' 30.0" x 74.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 72.00' S= 0.0135 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=5.37 cfs @ 12.75 hrs HW=74.05' TW=0.00' (Dynamic Tailwater) 1=Culvert (Inlet Controls 5.37 cfs @ 2.75 fps) Summary for Pond SD7: Inflow Area = 4.749 ac, 12.25% Impervious, Inflow Depth > 1.68" for 10 year event Inflow = 4.63 cfs @ 12.38 hrs, Volume= 0.667 af Outflow = 4.63 cfs @ 12.38 hrs, Volume= 0.667 af, Atten= 0%, Lag= 0.0 min Primary = 4.63 cfs @ 12.38 hrs, Volume= 0.667 af Peak Elev= 80.39' @ 12.40 hrs Device Routing Invert Outlet Devices #1 Primary 79.00' 18.0" x 735.0' long Culvert CPP, projecting, no headwall, Ke= 0.900

3203-POST Layover Facility Post Development Type III 24-hr 10 year Rainfall=4.70" Page 21 Outlet Invert= 76.62' S= 0.0032 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=4.57 cfs @ 12.38 hrs HW=80.38' TW=78.26' (Dynamic Tailwater) 1=Culvert (Outlet Controls 4.57 cfs @ 3.51 fps) Summary for Pond WP1: Inflow Area = 7.318 ac, 29.67% Impervious, Inflow Depth > 2.01" for 10 year event Inflow = 9.96 cfs @ 12.10 hrs, Volume= 1.228 af Outflow = 3.35 cfs @ 12.85 hrs, Volume= 0.716 af, Atten= 66%, Lag= 44.8 min Primary = 3.35 cfs @ 12.85 hrs, Volume= 0.716 af Peak Elev= 78.49' @ 12.85 hrs Surf.Area= 12,354 sf Storage= 26,137 cf Plug-Flow detention time= 162.2 min calculated for 0.716 af (58% of inflow) Center-of-Mass det. time= 75.7 min ( 862.7-787.0 ) Volume Invert Avail.Storage Storage Description #1 76.00' 46,429 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 76.00 8,384 375.0 0 0 8,384 77.00 10,288 451.0 9,320 9,320 13,397 78.00 11,674 462.0 10,974 20,293 14,317 79.00 13,092 478.0 12,376 32,670 15,603 80.00 14,437 490.0 13,759 46,429 16,646 Device Routing Invert Outlet Devices #1 Primary 73.00' 24.0" x 19.3' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 72.80' S= 0.0104 '/' Cc= 0.900 n= 0.012 #2 Device 1 78.10' 4.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height #3 Device 1 79.00' 21.1' long x 0.7' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 Coef. (English) 2.76 2.82 2.93 3.09 3.18 3.22 3.27 3.30 3.32 3.31 3.32 #4 Device 1 73.67' 1.5" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=3.35 cfs @ 12.85 hrs HW=78.49' TW=74.02' (Dynamic Tailwater) 1=Culvert (Passes 3.35 cfs of 25.23 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 3.23 cfs @ 2.13 fps) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 4=Orifice/Grate (Orifice Controls 0.12 cfs @ 10.17 fps)

3203-POST Layover Facility Post Development Type III 24-hr 25 year Rainfall=5.50" Page 22 Summary for Subcatchment 1: Runoff = 3.57 cfs @ 12.47 hrs, Volume= 0.436 af, Depth> 1.58" Type III 24-hr 25 year Rainfall=5.50" 85,716 76 Gravel roads, HSG A 56,324 39 >75% Grass cover, Good, HSG A 1,876 98 Paved parking & roofs 143,916 62 Weighted Average 142,040 Pervious Area 1,876 Impervious Area 8.5 50 0.0200 0.10 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 22.5 1,430 0.0050 1.06 Shallow Concentrated Flow, B-C Grassed Waterway Kv= 15.0 fps 31.0 1,480 Total Summary for Subcatchment 1A: Runoff = 6.48 cfs @ 12.09 hrs, Volume= 0.494 af, Depth> 4.71" Type III 24-hr 25 year Rainfall=5.50" 2,505 61 >75% Grass cover, Good, HSG B 52,272 98 Paved parking & roofs 54,777 96 Weighted Average 2,505 Pervious Area 52,272 Impervious Area 3.4 18 0.0100 0.09 Sheet Flow, A-B Grass: Short n= 0.150 P2= 3.00" 2.9 614 0.0020 3.49 10.96 Circular Channel (pipe), B-C Diam= 24.0" Area= 3.1 sf Perim= 6.3' r= 0.50' n= 0.012 6.3 632 Total

3203-POST Layover Facility Post Development Type III 24-hr 25 year Rainfall=5.50" Page 23 Summary for Subcatchment 1A-2: BACK ROOF AREA Runoff = 2.83 cfs @ 12.09 hrs, Volume= 0.219 af, Depth> 4.87" Type III 24-hr 25 year Rainfall=5.50" 23,459 98 Paved parking & roofs 23,459 Impervious Area 6.0 Direct Entry, Summary for Subcatchment 2: Runoff = 0.48 cfs @ 12.98 hrs, Volume= 0.107 af, Depth> 0.61" Type III 24-hr 25 year Rainfall=5.50" 13,000 98 Paved parking & roofs 78,499 39 >75% Grass cover, Good, HSG A 91,499 47 Weighted Average 78,499 Pervious Area 13,000 Impervious Area 26.9 150 0.0100 0.09 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 29.9 2,255 0.0070 1.25 Shallow Concentrated Flow, B-C Grassed Waterway Kv= 15.0 fps 56.8 2,405 Total Summary for Subcatchment 3: Runoff = 2.08 cfs @ 12.34 hrs, Volume= 0.220 af, Depth> 2.91" Type III 24-hr 25 year Rainfall=5.50"

3203-POST Layover Facility Post Development Type III 24-hr 25 year Rainfall=5.50" Page 24 28,572 85 Gravel roads, HSG B 10,924 61 >75% Grass cover, Good, HSG B 39,496 78 Weighted Average 39,496 Pervious Area 5.4 150 0.0050 0.46 Sheet Flow, A-B n= 0.023 P2= 3.00" 18.7 554 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 24.1 704 Total Summary for Subcatchment 4: Runoff = 0.95 cfs @ 12.22 hrs, Volume= 0.106 af, Depth> 0.74" Type III 24-hr 25 year Rainfall=5.50" 55,892 43 Woods/grass comb., Fair, HSG A 18,931 65 Woods/grass comb., Fair, HSG B 74,823 49 Weighted Average 74,823 Pervious Area 0.5 30 0.0200 1.05 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.00" 11.0 2,892 0.0070 4.39 52.70 Channel Flow, B-C Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 11.5 2,922 Total Summary for Subcatchment 5: Runoff = 0.37 cfs @ 12.45 hrs, Volume= 0.048 af, Depth> 0.91" Type III 24-hr 25 year Rainfall=5.50" 1,502 98 Paved parking & roofs 7,082 76 Gravel roads, HSG A 18,749 39 >75% Grass cover, Good, HSG A 27,333 52 Weighted Average 25,831 Pervious Area 1,502 Impervious Area

3203-POST Layover Facility Post Development Type III 24-hr 25 year Rainfall=5.50" Page 25 25.7 110 0.0060 0.07 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" Summary for Subcatchment 6: Runoff = 2.37 cfs @ 12.41 hrs, Volume= 0.274 af, Depth> 2.91" Type III 24-hr 25 year Rainfall=5.50" 2,660 39 >75% Grass cover, Good, HSG A 23,270 76 Gravel roads, HSG A 23,270 85 Gravel roads, HSG B 49,200 78 Weighted Average 49,200 Pervious Area 6.1 125 0.0060 0.34 Sheet Flow, A-B n= 0.035 P2= 3.00" 23.3 692 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 29.4 817 Total Summary for Subcatchment 7: Runoff = 1.07 cfs @ 12.47 hrs, Volume= 0.130 af, Depth> 2.29" Type III 24-hr 25 year Rainfall=5.50" 4,294 39 >75% Grass cover, Good, HSG A 25,349 76 Gravel roads, HSG A 29,643 71 Weighted Average 29,643 Pervious Area

3203-POST Layover Facility Post Development Type III 24-hr 25 year Rainfall=5.50" Page 26 26.9 150 0.0100 0.09 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 4.9 146 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 0.9 187 0.0050 3.47 2.73 Circular Channel (pipe), C-D Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 32.7 483 Total Summary for Subcatchment 8: Runoff = 1.95 cfs @ 12.31 hrs, Volume= 0.198 af, Depth> 1.82" Type III 24-hr 25 year Rainfall=5.50" 27,306 39 >75% Grass cover, Good, HSG A 12,833 76 Gravel roads, HSG A 7,526 98 Water Surface 9,455 98 Paved parking & roofs 57,120 65 Weighted Average 40,139 Pervious Area 16,981 Impervious Area 14.7 100 0.0200 0.11 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 6.1 256 0.0100 0.70 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 20.8 356 Total Summary for Reach POI1: Inflow Area = 12.946 ac, 19.08% Impervious, Inflow Depth > 1.55" for 25 year event Inflow = 10.29 cfs @ 12.61 hrs, Volume= 1.668 af Outflow = 10.29 cfs @ 12.61 hrs, Volume= 1.668 af, Atten= 0%, Lag= 0.0 min Summary for Reach POI2: Inflow Area = 0.627 ac, 5.50% Impervious, Inflow Depth > 0.91" for 25 year event Inflow = 0.37 cfs @ 12.45 hrs, Volume= 0.048 af Outflow = 0.37 cfs @ 12.45 hrs, Volume= 0.048 af, Atten= 0%, Lag= 0.0 min

3203-POST Layover Facility Post Development Type III 24-hr 25 year Rainfall=5.50" Page 27 Summary for Pond CB1: Inflow Area = 6.007 ac, 29.66% Impervious, Inflow Depth > 2.73" for 25 year event Inflow = 11.41 cfs @ 12.10 hrs, Volume= 1.369 af Outflow = 11.41 cfs @ 12.10 hrs, Volume= 1.369 af, Atten= 0%, Lag= 0.0 min Primary = 11.41 cfs @ 12.10 hrs, Volume= 1.369 af Peak Elev= 78.90' @ 12.58 hrs Device Routing Invert Outlet Devices #1 Primary 76.35' 30.0" x 280.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 76.06' S= 0.0010 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=10.29 cfs @ 12.10 hrs HW=78.52' TW=77.99' (Dynamic Tailwater) 1=Culvert (Outlet Controls 10.29 cfs @ 3.04 fps) Summary for Pond CB15: Inflow Area = 1.129 ac, 0.00% Impervious, Inflow Depth > 2.91" for 25 year event Inflow = 2.37 cfs @ 12.41 hrs, Volume= 0.274 af Outflow = 2.07 cfs @ 12.56 hrs, Volume= 0.274 af, Atten= 13%, Lag= 9.0 min Primary = 0.47 cfs @ 12.56 hrs, Volume= 0.187 af Secondary = 1.61 cfs @ 12.56 hrs, Volume= 0.087 af Peak Elev= 80.72' @ 12.56 hrs Surf.Area= 1,084 sf Storage= 1,289 cf Plug-Flow detention time= 9.9 min calculated for 0.273 af (100% of inflow) Center-of-Mass det. time= 9.8 min ( 816.2-806.4 ) Volume Invert Avail.Storage Storage Description #1 76.70' 1,608 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 76.70 4 0 0 77.00 4 1 1 78.00 4 4 5 78.90 4 4 9 79.00 404 20 29 80.00 775 590 619 81.00 1,203 989 1,608

3203-POST Layover Facility Post Development Type III 24-hr 25 year Rainfall=5.50" Page 28 Device Routing Invert Outlet Devices #1 Primary 76.70' 3.0" Vert. Orifice/Grate C= 0.600 #2 Secondary 80.10' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 #3 Device 2 76.60' 12.0" x 286.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 75.10' S= 0.0052 '/' Cc= 0.900 n= 0.012 #4 Secondary 80.80' 10.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=0.47 cfs @ 12.56 hrs HW=80.72' TW=74.46' (Dynamic Tailwater) 1=Orifice/Grate (Orifice Controls 0.47 cfs @ 9.50 fps) Secondary OutFlow Max=1.60 cfs @ 12.56 hrs HW=80.72' TW=74.46' (Dynamic Tailwater) 2=Orifice/Grate (Passes 1.60 cfs of 12.74 cfs potential flow) 3=Culvert (Outlet Controls 1.60 cfs @ 2.04 fps) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Summary for Pond CB9: Inflow Area = 1.445 ac, 37.26% Impervious, Inflow Depth > 3.64" for 25 year event Inflow = 3.89 cfs @ 12.10 hrs, Volume= 0.439 af Outflow = 3.89 cfs @ 12.10 hrs, Volume= 0.439 af, Atten= 0%, Lag= 0.0 min Primary = 3.89 cfs @ 12.10 hrs, Volume= 0.439 af Peak Elev= 82.14' @ 12.42 hrs Device Routing Invert Outlet Devices #1 Primary 79.72' 12.0" x 76.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 79.50' S= 0.0029 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=3.69 cfs @ 12.10 hrs HW=81.99' TW=80.47' (Dynamic Tailwater) 1=Culvert (Inlet Controls 3.69 cfs @ 4.69 fps) Summary for Pond DMH1: Inflow Area = 6.007 ac, 29.66% Impervious, Inflow Depth > 2.73" for 25 year event Inflow = 11.41 cfs @ 12.10 hrs, Volume= 1.369 af Outflow = 11.41 cfs @ 12.10 hrs, Volume= 1.369 af, Atten= 0%, Lag= 0.0 min Primary = 11.41 cfs @ 12.10 hrs, Volume= 1.369 af Peak Elev= 78.79' @ 12.62 hrs Device Routing Invert Outlet Devices #1 Primary 76.06' 30.0" x 60.7' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 76.00' S= 0.0010 '/' Cc= 0.900 n= 0.012

3203-POST Layover Facility Post Development Type III 24-hr 25 year Rainfall=5.50" Page 29 Primary OutFlow Max=9.54 cfs @ 12.10 hrs HW=77.99' TW=77.61' (Dynamic Tailwater) 1=Culvert (Inlet Controls 9.54 cfs @ 2.35 fps) Summary for Pond DMH2: Inflow Area = 2.101 ac, 14.21% Impervious, Inflow Depth > 0.61" for 25 year event Inflow = 0.48 cfs @ 12.98 hrs, Volume= 0.107 af Outflow = 0.48 cfs @ 12.98 hrs, Volume= 0.107 af, Atten= 0%, Lag= 0.0 min Primary = 0.48 cfs @ 12.98 hrs, Volume= 0.107 af Peak Elev= 74.53' @ 12.71 hrs Device Routing Invert Outlet Devices #1 Primary 74.00' 24.0" x 104.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 73.50' S= 0.0048 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=0.55 cfs @ 12.98 hrs HW=74.44' TW=74.22' (Dynamic Tailwater) 1=Culvert (Outlet Controls 0.55 cfs @ 1.61 fps) Summary for Pond DMH3: Inflow Area = 11.228 ac, 22.00% Impervious, Inflow Depth > 1.67" for 25 year event Inflow = 9.85 cfs @ 12.62 hrs, Volume= 1.562 af Outflow = 9.85 cfs @ 12.62 hrs, Volume= 1.562 af, Atten= 0%, Lag= 0.0 min Primary = 9.85 cfs @ 12.62 hrs, Volume= 1.562 af Peak Elev= 74.48' @ 12.62 hrs Device Routing Invert Outlet Devices #1 Primary 73.00' 30.0" x 74.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 72.00' S= 0.0135 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=9.82 cfs @ 12.62 hrs HW=74.47' TW=0.00' (Dynamic Tailwater) 1=Culvert (Inlet Controls 9.82 cfs @ 3.26 fps) Summary for Pond SD7: Inflow Area = 4.749 ac, 12.25% Impervious, Inflow Depth > 2.21" for 25 year event Inflow = 6.32 cfs @ 12.38 hrs, Volume= 0.875 af Outflow = 6.32 cfs @ 12.38 hrs, Volume= 0.875 af, Atten= 0%, Lag= 0.0 min Primary = 6.32 cfs @ 12.38 hrs, Volume= 0.875 af Peak Elev= 81.32' @ 12.41 hrs Device Routing Invert Outlet Devices #1 Primary 79.00' 18.0" x 735.0' long Culvert CPP, projecting, no headwall, Ke= 0.900

3203-POST Layover Facility Post Development Type III 24-hr 25 year Rainfall=5.50" Page 30 Outlet Invert= 76.62' S= 0.0032 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=6.19 cfs @ 12.38 hrs HW=81.27' TW=78.73' (Dynamic Tailwater) 1=Culvert (Outlet Controls 6.19 cfs @ 3.50 fps) Summary for Pond WP1: Inflow Area = 7.318 ac, 29.67% Impervious, Inflow Depth > 2.57" for 25 year event Inflow = 12.42 cfs @ 12.11 hrs, Volume= 1.567 af Outflow = 6.55 cfs @ 12.65 hrs, Volume= 1.052 af, Atten= 47%, Lag= 32.4 min Primary = 6.55 cfs @ 12.65 hrs, Volume= 1.052 af Peak Elev= 78.71' @ 12.65 hrs Surf.Area= 12,667 sf Storage= 28,887 cf Plug-Flow detention time= 137.6 min calculated for 1.052 af (67% of inflow) Center-of-Mass det. time= 62.7 min ( 848.9-786.1 ) Volume Invert Avail.Storage Storage Description #1 76.00' 46,429 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 76.00 8,384 375.0 0 0 8,384 77.00 10,288 451.0 9,320 9,320 13,397 78.00 11,674 462.0 10,974 20,293 14,317 79.00 13,092 478.0 12,376 32,670 15,603 80.00 14,437 490.0 13,759 46,429 16,646 Device Routing Invert Outlet Devices #1 Primary 73.00' 24.0" x 19.3' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 72.80' S= 0.0104 '/' Cc= 0.900 n= 0.012 #2 Device 1 78.10' 4.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height #3 Device 1 79.00' 21.1' long x 0.7' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 Coef. (English) 2.76 2.82 2.93 3.09 3.18 3.22 3.27 3.30 3.32 3.31 3.32 #4 Device 1 73.67' 1.5" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=6.55 cfs @ 12.65 hrs HW=78.71' TW=74.47' (Dynamic Tailwater) 1=Culvert (Passes 6.55 cfs of 24.57 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 6.43 cfs @ 2.73 fps) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 4=Orifice/Grate (Orifice Controls 0.12 cfs @ 9.91 fps)

Layover Facility Post Development 3203-POST Type III 24-hr 100 year Rainfall=6.70" Page 31 Summary for Subcatchment 1: Runoff = 5.41 cfs @ 12.46 hrs, Volume= 0.646 af, Depth> 2.35" Type III 24-hr 100 year Rainfall=6.70" 85,716 76 Gravel roads, HSG A 56,324 39 >75% Grass cover, Good, HSG A 1,876 98 Paved parking & roofs 143,916 62 Weighted Average 142,040 Pervious Area 1,876 Impervious Area 8.5 50 0.0200 0.10 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 22.5 1,430 0.0050 1.06 Shallow Concentrated Flow, B-C Grassed Waterway Kv= 15.0 fps 31.0 1,480 Total Summary for Subcatchment 1A: Runoff = 7.94 cfs @ 12.09 hrs, Volume= 0.609 af, Depth> 5.82" Type III 24-hr 100 year Rainfall=6.70" 2,505 61 >75% Grass cover, Good, HSG B 52,272 98 Paved parking & roofs 54,777 96 Weighted Average 2,505 Pervious Area 52,272 Impervious Area 3.4 18 0.0100 0.09 Sheet Flow, A-B Grass: Short n= 0.150 P2= 3.00" 2.9 614 0.0020 3.49 10.96 Circular Channel (pipe), B-C Diam= 24.0" Area= 3.1 sf Perim= 6.3' r= 0.50' n= 0.012 6.3 632 Total

Layover Facility Post Development 3203-POST Type III 24-hr 100 year Rainfall=6.70" Page 32 Summary for Subcatchment 1A-2: BACK ROOF AREA Runoff = 3.46 cfs @ 12.09 hrs, Volume= 0.268 af, Depth> 5.97" Type III 24-hr 100 year Rainfall=6.70" 23,459 98 Paved parking & roofs 23,459 Impervious Area 6.0 Direct Entry, Summary for Subcatchment 2: Runoff = 0.99 cfs @ 12.91 hrs, Volume= 0.190 af, Depth> 1.08" Type III 24-hr 100 year Rainfall=6.70" 13,000 98 Paved parking & roofs 78,499 39 >75% Grass cover, Good, HSG A 91,499 47 Weighted Average 78,499 Pervious Area 13,000 Impervious Area 26.9 150 0.0100 0.09 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 29.9 2,255 0.0070 1.25 Shallow Concentrated Flow, B-C Grassed Waterway Kv= 15.0 fps 56.8 2,405 Total Summary for Subcatchment 3: Runoff = 2.77 cfs @ 12.33 hrs, Volume= 0.296 af, Depth> 3.92" Type III 24-hr 100 year Rainfall=6.70"

Layover Facility Post Development 3203-POST Type III 24-hr 100 year Rainfall=6.70" Page 33 28,572 85 Gravel roads, HSG B 10,924 61 >75% Grass cover, Good, HSG B 39,496 78 Weighted Average 39,496 Pervious Area 5.4 150 0.0050 0.46 Sheet Flow, A-B n= 0.023 P2= 3.00" 18.7 554 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 24.1 704 Total Summary for Subcatchment 4: Runoff = 1.93 cfs @ 12.19 hrs, Volume= 0.181 af, Depth> 1.27" Type III 24-hr 100 year Rainfall=6.70" 55,892 43 Woods/grass comb., Fair, HSG A 18,931 65 Woods/grass comb., Fair, HSG B 74,823 49 Weighted Average 74,823 Pervious Area 0.5 30 0.0200 1.05 Sheet Flow, A-B Smooth surfaces n= 0.011 P2= 3.00" 11.0 2,892 0.0070 4.39 52.70 Channel Flow, B-C Area= 12.0 sf Perim= 11.0' r= 1.09' n= 0.030 11.5 2,922 Total Summary for Subcatchment 5: Runoff = 0.66 cfs @ 12.41 hrs, Volume= 0.078 af, Depth> 1.49" Type III 24-hr 100 year Rainfall=6.70" 1,502 98 Paved parking & roofs 7,082 76 Gravel roads, HSG A 18,749 39 >75% Grass cover, Good, HSG A 27,333 52 Weighted Average 25,831 Pervious Area 1,502 Impervious Area

Layover Facility Post Development 3203-POST Type III 24-hr 100 year Rainfall=6.70" Page 34 25.7 110 0.0060 0.07 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" Summary for Subcatchment 6: Runoff = 3.17 cfs @ 12.40 hrs, Volume= 0.368 af, Depth> 3.91" Type III 24-hr 100 year Rainfall=6.70" 2,660 39 >75% Grass cover, Good, HSG A 23,270 76 Gravel roads, HSG A 23,270 85 Gravel roads, HSG B 49,200 78 Weighted Average 49,200 Pervious Area 6.1 125 0.0060 0.34 Sheet Flow, A-B n= 0.035 P2= 3.00" 23.3 692 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 29.4 817 Total Summary for Subcatchment 7: Runoff = 1.50 cfs @ 12.46 hrs, Volume= 0.181 af, Depth> 3.20" Type III 24-hr 100 year Rainfall=6.70" 4,294 39 >75% Grass cover, Good, HSG A 25,349 76 Gravel roads, HSG A 29,643 71 Weighted Average 29,643 Pervious Area

Layover Facility Post Development 3203-POST Type III 24-hr 100 year Rainfall=6.70" Page 35 26.9 150 0.0100 0.09 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 4.9 146 0.0050 0.49 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 0.9 187 0.0050 3.47 2.73 Circular Channel (pipe), C-D Diam= 12.0" Area= 0.8 sf Perim= 3.1' r= 0.25' n= 0.012 32.7 483 Total Summary for Subcatchment 8: Runoff = 2.87 cfs @ 12.30 hrs, Volume= 0.288 af, Depth> 2.64" Type III 24-hr 100 year Rainfall=6.70" 27,306 39 >75% Grass cover, Good, HSG A 12,833 76 Gravel roads, HSG A 7,526 98 Water Surface 9,455 98 Paved parking & roofs 57,120 65 Weighted Average 40,139 Pervious Area 16,981 Impervious Area 14.7 100 0.0200 0.11 Sheet Flow, A-B Grass: Dense n= 0.240 P2= 3.00" 6.1 256 0.0100 0.70 Shallow Concentrated Flow, B-C Short Grass Pasture Kv= 7.0 fps 20.8 356 Total Summary for Reach POI1: Inflow Area = 12.946 ac, 19.08% Impervious, Inflow Depth > 2.32" for 100 year event Inflow = 17.81 cfs @ 12.50 hrs, Volume= 2.507 af Outflow = 17.81 cfs @ 12.50 hrs, Volume= 2.507 af, Atten= 0%, Lag= 0.0 min Summary for Reach POI2: Inflow Area = 0.627 ac, 5.50% Impervious, Inflow Depth > 1.49" for 100 year event Inflow = 0.66 cfs @ 12.41 hrs, Volume= 0.078 af Outflow = 0.66 cfs @ 12.41 hrs, Volume= 0.078 af, Atten= 0%, Lag= 0.0 min

Layover Facility Post Development 3203-POST Type III 24-hr 100 year Rainfall=6.70" Page 36 Summary for Pond CB1: Inflow Area = 6.007 ac, 29.66% Impervious, Inflow Depth > 3.64" for 100 year event Inflow = 14.69 cfs @ 12.10 hrs, Volume= 1.820 af Outflow = 14.69 cfs @ 12.10 hrs, Volume= 1.820 af, Atten= 0%, Lag= 0.0 min Primary = 14.69 cfs @ 12.10 hrs, Volume= 1.820 af Peak Elev= 79.59' @ 12.45 hrs Device Routing Invert Outlet Devices #1 Primary 76.35' 30.0" x 280.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 76.06' S= 0.0010 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=11.68 cfs @ 12.10 hrs HW=78.99' TW=78.55' (Dynamic Tailwater) 1=Culvert (Outlet Controls 11.68 cfs @ 2.80 fps) Summary for Pond CB15: Inflow Area = 1.129 ac, 0.00% Impervious, Inflow Depth > 3.91" for 100 year event Inflow = 3.17 cfs @ 12.40 hrs, Volume= 0.368 af Outflow = 3.14 cfs @ 12.46 hrs, Volume= 0.368 af, Atten= 1%, Lag= 3.3 min Primary = 0.48 cfs @ 12.46 hrs, Volume= 0.226 af Secondary = 2.67 cfs @ 12.46 hrs, Volume= 0.142 af Peak Elev= 80.91' @ 12.46 hrs Surf.Area= 1,163 sf Storage= 1,498 cf Plug-Flow detention time= 10.0 min calculated for 0.367 af (100% of inflow) Center-of-Mass det. time= 10.0 min ( 809.6-799.6 ) Volume Invert Avail.Storage Storage Description #1 76.70' 1,608 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 76.70 4 0 0 77.00 4 1 1 78.00 4 4 5 78.90 4 4 9 79.00 404 20 29 80.00 775 590 619 81.00 1,203 989 1,608

Layover Facility Post Development 3203-POST Type III 24-hr 100 year Rainfall=6.70" Page 37 Device Routing Invert Outlet Devices #1 Primary 76.70' 3.0" Vert. Orifice/Grate C= 0.600 #2 Secondary 80.10' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 #3 Device 2 76.60' 12.0" x 286.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 75.10' S= 0.0052 '/' Cc= 0.900 n= 0.012 #4 Secondary 80.80' 10.0' long x 4.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.38 2.54 2.69 2.68 2.67 2.67 2.65 2.66 2.66 2.68 2.72 2.73 2.76 2.79 2.88 3.07 3.32 Primary OutFlow Max=0.48 cfs @ 12.46 hrs HW=80.91' TW=75.04' (Dynamic Tailwater) 1=Orifice/Grate (Orifice Controls 0.48 cfs @ 9.73 fps) Secondary OutFlow Max=2.65 cfs @ 12.46 hrs HW=80.91' TW=75.04' (Dynamic Tailwater) 2=Orifice/Grate (Passes 1.83 cfs of 17.29 cfs potential flow) 3=Culvert (Outlet Controls 1.83 cfs @ 2.33 fps) 4=Broad-Crested Rectangular Weir (Weir Controls 0.82 cfs @ 0.77 fps) Summary for Pond CB9: Inflow Area = 1.445 ac, 37.26% Impervious, Inflow Depth > 4.68" for 100 year event Inflow = 4.91 cfs @ 12.10 hrs, Volume= 0.564 af Outflow = 4.91 cfs @ 12.10 hrs, Volume= 0.564 af, Atten= 0%, Lag= 0.0 min Primary = 4.91 cfs @ 12.10 hrs, Volume= 0.564 af Peak Elev= 86.25' @ 12.41 hrs Device Routing Invert Outlet Devices #1 Primary 79.72' 12.0" x 76.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 79.50' S= 0.0029 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=3.82 cfs @ 12.10 hrs HW=83.43' TW=81.79' (Dynamic Tailwater) 1=Culvert (Inlet Controls 3.82 cfs @ 4.87 fps) Summary for Pond DMH1: Inflow Area = 6.007 ac, 29.66% Impervious, Inflow Depth > 3.64" for 100 year event Inflow = 14.69 cfs @ 12.10 hrs, Volume= 1.820 af Outflow = 14.69 cfs @ 12.10 hrs, Volume= 1.820 af, Atten= 0%, Lag= 0.0 min Primary = 14.69 cfs @ 12.10 hrs, Volume= 1.820 af Peak Elev= 79.27' @ 12.46 hrs Device Routing Invert Outlet Devices #1 Primary 76.06' 30.0" x 60.7' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 76.00' S= 0.0010 '/' Cc= 0.900 n= 0.012

Layover Facility Post Development 3203-POST Type III 24-hr 100 year Rainfall=6.70" Page 38 Primary OutFlow Max=11.57 cfs @ 12.10 hrs HW=78.55' TW=78.16' (Dynamic Tailwater) 1=Culvert (Inlet Controls 11.57 cfs @ 2.36 fps) Summary for Pond DMH2: Inflow Area = 2.101 ac, 14.21% Impervious, Inflow Depth > 1.08" for 100 year event Inflow = 0.99 cfs @ 12.91 hrs, Volume= 0.190 af Outflow = 0.99 cfs @ 12.91 hrs, Volume= 0.190 af, Atten= 0%, Lag= 0.0 min Primary = 0.99 cfs @ 12.91 hrs, Volume= 0.190 af Peak Elev= 75.08' @ 12.57 hrs Device Routing Invert Outlet Devices #1 Primary 74.00' 24.0" x 104.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 73.50' S= 0.0048 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=1.29 cfs @ 12.91 hrs HW=74.77' TW=74.59' (Dynamic Tailwater) 1=Culvert (Outlet Controls 1.29 cfs @ 1.72 fps) Summary for Pond DMH3: Inflow Area = 11.228 ac, 22.00% Impervious, Inflow Depth > 2.49" for 100 year event Inflow = 16.75 cfs @ 12.51 hrs, Volume= 2.325 af Outflow = 16.75 cfs @ 12.51 hrs, Volume= 2.325 af, Atten= 0%, Lag= 0.0 min Primary = 16.75 cfs @ 12.51 hrs, Volume= 2.325 af Peak Elev= 75.07' @ 12.51 hrs Device Routing Invert Outlet Devices #1 Primary 73.00' 30.0" x 74.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 72.00' S= 0.0135 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=16.71 cfs @ 12.51 hrs HW=75.06' TW=0.00' (Dynamic Tailwater) 1=Culvert (Inlet Controls 16.71 cfs @ 3.86 fps) Summary for Pond SD7: Inflow Area = 4.749 ac, 12.25% Impervious, Inflow Depth > 3.06" for 100 year event Inflow = 9.02 cfs @ 12.38 hrs, Volume= 1.210 af Outflow = 9.02 cfs @ 12.38 hrs, Volume= 1.210 af, Atten= 0%, Lag= 0.0 min Primary = 9.02 cfs @ 12.38 hrs, Volume= 1.210 af Peak Elev= 84.86' @ 12.40 hrs Device Routing Invert Outlet Devices #1 Primary 79.00' 18.0" x 735.0' long Culvert CPP, projecting, no headwall, Ke= 0.900

Layover Facility Post Development 3203-POST Type III 24-hr 100 year Rainfall=6.70" Page 39 Outlet Invert= 76.62' S= 0.0032 '/' Cc= 0.900 n= 0.012 Primary OutFlow Max=8.90 cfs @ 12.38 hrs HW=84.80' TW=79.54' (Dynamic Tailwater) 1=Culvert (Outlet Controls 8.90 cfs @ 5.04 fps) Summary for Pond WP1: Inflow Area = 7.318 ac, 29.67% Impervious, Inflow Depth > 3.46" for 100 year event Inflow = 16.29 cfs @ 12.11 hrs, Volume= 2.108 af Outflow = 11.71 cfs @ 12.52 hrs, Volume= 1.586 af, Atten= 28%, Lag= 24.8 min Primary = 11.71 cfs @ 12.52 hrs, Volume= 1.586 af Peak Elev= 78.99' @ 12.52 hrs Surf.Area= 13,074 sf Storage= 32,511 cf Plug-Flow detention time= 113.8 min calculated for 1.581 af (75% of inflow) Center-of-Mass det. time= 52.1 min ( 836.5-784.4 ) Volume Invert Avail.Storage Storage Description #1 76.00' 46,429 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 76.00 8,384 375.0 0 0 8,384 77.00 10,288 451.0 9,320 9,320 13,397 78.00 11,674 462.0 10,974 20,293 14,317 79.00 13,092 478.0 12,376 32,670 15,603 80.00 14,437 490.0 13,759 46,429 16,646 Device Routing Invert Outlet Devices #1 Primary 73.00' 24.0" x 19.3' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 72.80' S= 0.0104 '/' Cc= 0.900 n= 0.012 #2 Device 1 78.10' 4.0' long x 1.00' rise Sharp-Crested Rectangular Weir 2 End Contraction(s) 1.0' Crest Height #3 Device 1 79.00' 21.1' long x 0.7' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 Coef. (English) 2.76 2.82 2.93 3.09 3.18 3.22 3.27 3.30 3.32 3.31 3.32 #4 Device 1 73.67' 1.5" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=11.67 cfs @ 12.52 hrs HW=78.99' TW=75.06' (Dynamic Tailwater) 1=Culvert (Passes 11.67 cfs of 23.66 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Weir Controls 11.55 cfs @ 3.41 fps) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) 4=Orifice/Grate (Orifice Controls 0.12 cfs @ 9.54 fps)

ATTACHMENT B Water Quality Treatment Computations

TOTAL 185,010 105,415 290,425 86,998-29,045 11,577 - - 196,249 256,800 BRUNSWICK LAYOVER FACILITY WATER QUALITY CALCULATIONS NEW IMPERVIOUS AREA (SF) RETROFIT AREA WITH GENERAL STD. AT RETROFIT CREDIT TREATED IMPERVIOUS AREA (SF) TREATED DEVELOPED AREA (SF) NEW LANDSCAPE NEW DEVELOPED 187,118 18,403 21,691 0 AREA CREDIT * CREDITS (SF) TREATED AREA ID AREA (SF) AREA (SF) REQUIRED SIZING (SF) DESCRIPTION MULTIPLIER IMP. LAWN (YES/NO) BMP 1 & 1A 141,742 23,271 165,013 23,027 RAIL 0.6 13,816-27,630 LAWN 0.3-8,289 YES WET POND 155,558 2 893 44,715 45,608 - - - - - NO - 0 0 3 3,174 0 3,174 25,381 RAIL 0.6 15,229-10,960 LAWN 0.3-3,288 YES WET POND 4 0 0 0 - - - - - NO - 0 0 5 2,339 3,827 6,166 - - - - - NO - 0 0 6 11,033 2,824 13,857 0 RAIL 0.6 0 0 LAWN 0.3 0 NO - 0 7 3,541 5,075 8,616 - - - - - NO - 0 0 8 22,288 25,703 47,991 - - - 0 0 YES WET POND 22,288 47,991 TREATMENT SUMMARY IMPERVIOUS AREA SUMMARY DEVELOPED AREA SUMMARY NEW IMP. AREA (SF): 185,010 NEW DEVELOPED AREA (SF): 290,425 IMP. AEA RETROFIT CREDIT 29,045 NET DEVELOPED RETROFIT CREDIT (SF): 40,622 TREATED IMP. AREA (SF): 196,249 TREATED DEVELOPED AREA (SF): 256,800 % IMP. AREA TREATED: 106.07% % DEVELOPED AREA TREATED: 88.42% * CREDIT TABLE MITIGATION ACTIVITY SOURCE TYPE ROAD OR HIGH USE PARKING LOT RETROFIT WITH LOW USE PARKING LOT GENERAL STANDARDS ROOF OR OTHER IMP. AREA AT REQUIRED SIZING LAWN CREDIT EARNED 1.5 0.9 0.6 0.3 8/5/2014 JN: 3203

R:\3203-Brunswick Layover Facility\Eng\Stormwater and SWPPP\Water Quality Calculations.xls 1 of 1 PROPOSED WET POND #1 STAGE - STORAGE CALCULATIONS Stage Elev. Surf. Area Inc. Vol Cum. Vol Vol Above PP Notes 70 2,815 ft² - - 71 3,551 ft² 3,183 ft³ 3,183 ft³ 72 4,326 ft² 3,938 ft³ 7,121 ft³ 73 5,141 ft² 4,733 ft³ 11,854 ft³ 74 5,994 ft² 5,567 ft³ 17,421 ft³ 75 6,887 ft² 6,440 ft³ 23,861 ft³ 3.46 Mean Depth 76 8,384 ft² 7,635 ft³ 31,496 ft³ WQV Elevation 77 10,288 ft² 9,336 ft³ 40,832 ft³ 9,336 78 11,674 ft² 10,981 ft³ 51,813 ft³ 20,317 78.1 11,821 ft² 1,174 ft³ 52,987 ft³ 21,491 CPV Elevation 79 13,092 ft² 11,210 ft³ 64,197 ft³ 32,701 80 14,437 ft² 13,764 ft³ 77,961 ft³ 46,465 Wetpond WQV Required 31,330 ft³ Orifice Eqn: t=(2a/ (Ca2g)) (h 1^½ -h 2^½ ) Wetpond WQV Provided Wetpond WQV Elev. 31,496 ft³ 76.00 Discharge Coefficient C = 0.62 Orifice Size = 2.00 in Orifice Size = 0.17 ft Permanent Pool Elev. 76.00 Cross sectional Area of Orifice (a) = 0.022 ft² Vessel (A) = 11,674 ft² Wetpond CPV Required Wetpond CPV Provided Channel Protection Volume Elev. Flow length across permanent pool from inlet to outlet = Width of Permanent Pool = 20,886 ft³ Orifice Centerline Elevation = 73.67 21,491 ft³ 78.10 Length to Width Ratio = 2.66 :1 Underdrain length Required= 62.7 ft (3 ft/1000 cf CPV) Starting Water Level Ending Water Level t (sec) Stage Elevation Above Orifice (h1) Above Orifice (h2) Pond Area t (hrs) 0.00 sec 77.00 3.33 ft 3.33 ft 10,288 ft² 0.00 hrs 160 ft 55071.8 sec 78.00 4.33 ft 3.33 ft 11,674 ft² 15.30 hrs 54953.4 sec 79.00 5.33 ft 4.33 ft 13,092 ft² 15.26 hrs 60 ft Total Drawdown Time 30.56 hrs

ATTACHMENT C Pipe Sizing/Hydraulic Computations

ATTACHMENT D Flood Insurance Rate Map

ATTACHMENT E Inspection & Maintenance Manual

INSPECTION AND MAINTENANCE MANUAL FOR STORMWATER MANAGEMENT AND RELATED STORMWATER FACILITIES BRUNSWICK LAYOVER FACILITY BRUNSWICK, MAINE PREPARED FOR: NORTHERN NEW ENGLAND PASSENGER RAIL AUTHORITY (NNEPRA) 75 WEST COMMERCIAL STREET, SUITE 104 PORTLAND, MAINE 04101 PREPARED BY: DELUCA-HOFFMAN ASSOCIATES, INC. 778 MAIN STREET, SUITE 8 SOUTH PORTLAND, MAINE 04106 (207) 775-1121 AUGUST 2013

TABLE OF CONTENTS SECTION DESCRIPTION PAGE I. INTRODUCTION... 1 A. Guidelines Overview... 1 II. PROJECT OVERVIEW... 2 III. STANDARD INSPECTION/MAINTENANCE DESCRIPTIONS... 3 A. Pond Overflow... 3 B. Control Structures... 4 C. Berms... 5 D. Stormwater Inlets... 6 E. Tributary Drainage System... 7 F. Vegetated Swales... 8 G. Pond Lining... 10 H. Sorbent Booms... 10 I. Parking Lot Cleaning... 10 J. Litter... 10 K. Summary Checklist... 10 IV. PROGRAM ADMINISTRATION... 11 A. General... 11 B. Record Keeping... 11 C. Contract Services... 11 APPENDICES Appendix A Sample Inspection Logs Appendix B Permits for Project Appendix C Summary Checklist for Inspection and Maintenance

I. INTRODUCTION Relatively complex stormwater management facilities are commonly installed in development projects including school campuses, commercial facilities, and many other developments. The complexity and goals of these systems vary with the nature of the receiving water, as well as the type of development. Runoff from developed areas of the project, including rooftops, paved or lawn areas, may contain materials that can impact the receiving waters. Source control and the installation of wet ponds, infiltration galleries, green infrastructure and water quality units, often combined with pretreatment measures or followed by vegetated buffer strips and other best management practices, can significantly reduce the non-point pollution discharge from the developed area. These measures are particularly important to projects in the watersheds of sensitive water bodies, or projects with potential impacts to groundwater. With the increased cost of land and development, there is an increased tendency to construct portions of the stormwater management systems underground or to provide multifaceted management systems. The effectiveness of water quality management provisions and other components of the stormwater management system are dependent on their design, upkeep, and maintenance to assure they meet their intended function over an extended period of years. It is critical that the stormwater management facilities are regularly inspected, and that maintenance is performed on an as-needed basis. It must also be recognized that the effectiveness of these facilities, and their maintenance requirements, are related to the stormwater drainage facilities that collect and transport the flow to the ponds or treatment measures. Thus, maintenance should be directed to the total system, not just the pond or primary stormwater management facility. The MeDEP Stormwater Permits now require a 5-year inspection report. The purpose of this document is to define, in detail, the inspection and maintenance requirements for the Brunswick Layover facility deemed necessary to assure that the stormwater management facilities function as intended on a long-term basis. Subsequent sections identify individual maintenance items, give a brief commentary of the function and need for the item, a description of the work required, and a suggested frequency of accomplishment. While the suggested programs and schedules must be adapted to specific projects, the material presented should provide guidance for a successful long-term program. A. GUIDELINES OVERVIEW A summary of the individual components of stormwater management facilities has been prepared. The format used in the summary is as follows: Preface: A general description of what function/benefit the element is intended to provide. This is a short summary and not intended to provide the design basis which can be found in other sources. Inspection: This section provides the inspection requirements for the individual component. JN3203 Inspection & Maintenance Manual August 2013 Page 1 Brunswick Layover Facility Brunswick, ME

Maintenance: The section provides general information on the routine maintenance requirements of this element. Frequency: This section outlines the best judgment of the designer on the system to the frequency of maintenance. Comments: This section provides any particular comment on the site-specific features of this element. This is a summary only. The owner/operator should review the design drawings and documents carefully to understand the particular elements of the project. The end of this section should allow for the owner/operator to make notes on the specific program. This may include the selected maintenance procedure, cross-references to applicable design drawings, etc. A list of the individual inspection/maintenance elements is provided in the table of contents. The guidelines are proposed for initial use with adjustments made as appropriate based upon specific project experience. II. PROJECT OVERVIEW Key permits issued (or applied for) on the project include: MeDEP Stormwater Management Law MeDEP Maine Pollutant Discharge Elimination System Multi-Sector General Permit and SWPPP The permit applications for the project include the design information for the stormwater system. A copy of the permits and Stormwater Management Report should be appended to this manual as Appendix B. The Owner/Operator of the stormwater management system should review these permits for a general description and background of the project, as well as any specific permit conditions or requirements of the project. The applicant has retained DeLuca-Hoffman Associates, Inc. for civil engineering for the proposed site improvements at the Brunswick Layover Facility. DeLuca-Hoffman Associates, Inc. has prepared the design for the stormwater management facilities for this project and may be contacted at: DeLuca-Hoffman Associates, Inc. 778 Main Street, Suite 8 South Portland, Maine 04106 (207) 775-1121 It is recommended any particular questions on the design intent or similar issues be directed to the designer of the system. The applicable plans/design documents which apply to the project are: 1. Civil Site Plans/Permit Applications 2. The Erosion Control/Sedimentation Control Plan for the project. 3. The Stormwater Management Plan for the project. 4. O&M Stormwater Maintenance Plan for the project. JN3203 Inspection & Maintenance Manual August 2013 Page 2 Brunswick Layover Facility Brunswick, ME

A copy of these documents should be retained with the manual. III. STANDARD INSPECTION/MAINTENANCE DESCRIPTIONS The following narratives describe the inspection/maintenance provisions for the Stormwater Management area. These O&M procedures will complement scheduled sweeping of the pavement areas anticipated to occur at least twice per year. The MeDEP will require the stormwater system be certified to meet the basis of design at five year increments. Proper O&M is necessary to make sure the system can be certified. A. POND OVERFLOW Preface: The stormwater water quality facilities proposed for the project include one wet pond. When storm events occur, the underdrain bench becomes saturated and detains inflowing water. As the storm continues, water in the pond is displaced by the entering flow with peak inflows attenuated by the basins control features. The pond includes a hydraulic control structure at the discharge which is designed to attenuate flows which enter the pond and release it at a slower rate. If the filter surcharges beyond the 25 year design stage, excess flow would be discharged to an emergency overflow device contained within the outlet control structure. Inspection: The outlet control structure has been designed to regulate the discharge from storm events. Therefore, flow is anticipated to be released during and after each storm event. The control structure will be designed with a trash rack, an internal orifice, and a weir. Debris should be removed whenever observed. Entry may require CONFINED SPACE ENTRY procedures and appropriately trained personnel. The overflow device will be designed to operate infrequently but it is important to assure that it is operable as intended. Maintenance: Requirements for the overflow should be limited. Any brush or trees which become established near the overflow should be cut and kept in a cropped condition. Any debris which may accumulate over the overflow should be removed. Frequency: The trash rack on the outlet control structure spillway should be inspected on a weekly basis, and after a high intensity rainfall event (in excess of 3 inches in a 24- hour period). Maintenance should be conducted on an as needed basis. The outlet control structure should be inspected quarterly or if any unusually slow drawdown in the filter is observed. Inspection Personnel: The inspection is anticipated to be performed by maintenance personnel who will perform the minor maintenance/ inspection. Although the inspection will be recorded as made, any observations made/concerns, observations should be entered in the records maintained by the Owner. The spillways should be observed and debris removed during the annual inspection. Special Services: Major repairs would need to be addressed on a case-by-case basis by contracted personnel. JN3203 Inspection & Maintenance Manual August 2013 Page 3 Brunswick Layover Facility Brunswick, ME

B. CONTROL STRUCTURES Preface: The proposed wet pond will also provide detention which is controlled by the outlet control structure. Inspection: The outlet control structure must be inspected to assure it maintains its intended hydraulic characteristics. The inspection would note any debris or sediment which may accumulate in the structure and in the incoming and outlet pipes. It is noted that it does not take much debris or silt to alter the hydraulic characteristics of the discharge. The inlet should be inspected to assure it is not blocked or restricted or there is sediment to the extent that its flow characteristics may be altered. Maintenance: Maintenance of the control structure will consist primarily of removing debris which may accumulate. Frequency: The control structure should be inspected quarterly, and after a high intensity rainfall event (in excess of 3 inches in a 24-hour period). Debris and silt should be removed during each inspection. Maintenance/Inspection Responsibility: Inspection Personnel: The Maintenance Personnel of the Owner will perform the scheduled maintenance/inspection. OUTLET CONTROL STRUCTURE NOTE STRUCTURE (ABOVE CULVERT) HAS BEEN BACKFILLED TO ALLOW ACCESS, HOWEVER DOES NOT CREATE AN EYESORE OF A RAISED STRUCTURE. Dates of Inspections, maintenance performed, and any observed problems should be noted in the logs/records maintained by the Owner. Outside Contract Services: The outlet structure should be opened/inspected by the Maintenance Personnel of the Owner on a quarterly basis. The logs and records of inspections and maintenance of the control structures should also be reviewed by the contract agent if the Department elects to retain an outside agent for assistance. Replacement Parts/Repairs: Inspection personnel should have a bucket to remove debris. JN3203 Inspection & Maintenance Manual August 2013 Page 4 Brunswick Layover Facility Brunswick, ME

The outlet control structure is designed with bar racks. A sustained rise in water level would likely be due to a blockage of the orifice at the inlet from the underdrain pipes. C. BERMS Preface: Many times pond construction will include installation of an earthen berm or dike to contain the water. The pond is formed with both excavated slopes and constructed berms. The maintenance and monitoring discussed here applies to both the side slopes of excavated pond areas and the constructed pond berms. All excavated slopes and constructed berms must maintain their integrity to contain water without catastrophic leakage. Erosion or piping could cause filter failure. It is critical that the integrity of the berm be maintained. Inspection: The berm must be periodically inspected to note any sag, slope sloughing, erosion, cracking, or undesirable tree growth. Any defects in the berm must be noted and documented. It is noted that on larger ponds muskrats can burrow into the sidewall to the extent that the wall's structural integrity can be diminished. Any noted sags, or slope sloughing should be corrected after the causative factor has been identified and mitigated. If muskrat burrows become a problem, the muskrats should be trapped and removed from the site. This should be accomplished in cooperation with wildlife officials. Some situations have occurred where burrowing animals cause a significant problem with pond integrity. While this situation is generally rare, in certain instances it may warrant placement of a barrier. Chain link fence with shallow cover has been a successful deterrent in some cases. Frequency: Berm inspections should be done semiannually. Grassed areas along the top of the berm should be mowed monthly during the growing season. Repair of any berm defects should be accomplished in a timely manner to limit further deterioration. Maintenance Personnel: The Maintenance Personnel will perform the mowing/ brush removal as part of the grounds maintenance. Minor slumping or washouts will also be repaired by maintenance personnel, but should be noted in the records to determine if the problem is POND BERM NOTE STABILIZATION HAS reoccurring. The OCCURRED, VEGETATION HAS CAUGHT, SLOPES maintenance staff AND TOP HAVE BEEN MAINTAINED. PROPER should perform the MAINTENANCE HAS LED TO A STABILIZED FACILITY annual inspection and carefully walk/inspect all fill berms. JN3203 Inspection & Maintenance Manual August 2013 Page 5 Brunswick Layover Facility Brunswick, ME

Repairs: Minor repairs will be performed by maintenance personnel. More significant problems would require outside services on an as needed basis. If burrowing animals were to become a problem, the Owner should consult with knowledgeable professionals on remedial actions. D. STORMWATER INLETS Preface: The success of any stormwater facility relies on the ability to intercept stormwater runoff at the design locations. Stormwater inlets may include catch basins, open culverts, culverts with bar screens, and field inlets. Inlets exist throughout the system at the points of collection as well as at the outlet of many ponds. Bar racks are common on many inlet locations which intercept an open channel. This section is directed at maintenance of the actual inlet point. A later section addresses more substantive maintenance of the structures and conveyance facilities. The inlets contain sumps to retain sediment and avoid discharge to downgradient areas. Sumps will fill up over time and sediment should be removed annually. Inspection: The inspection of inlet points will need to be coordinated with other maintenance items, these include: Roadway/parking lot maintenance areas Building maintenance areas Grounds maintenance The key elements of the inspection are to assure the inlet entry point is clear of debris and will allow the intended water entry. Maintenance: The key maintenance is the removal of any blockage which restricts the entry of stormwater to the inlet. The removed material should be taken out of the area of the inlet and placed where it will not reenter the runoff collection system. Snow should be removed from inlets in parking lots/roadway areas. Grass clippings and leaves should be bagged and removed particularly near the yard inlets near the building or within in the rail track areas. Frequency: All inlets should be inspected on a monthly basis, and after/during significant storm events. A windshield survey is suitable for most inlets but off road inlets and pond structures require more rigorous inspection. Maintenance Personnel: The maintenance personnel will perform the normal maintenance/inspections of the inlets and culvert crossings. POORLY STABILIZED INLET ALLOWS ENTRANCE OF DEBRIS AND REDUCED CAPACITY JN3203 Inspection & Maintenance Manual August 2013 Page 6 Brunswick Layover Facility Brunswick, ME

Comments: None STABILIZED INLETS REDUCE DEBRIS ACCUMULATION AND MAINTAIN DESIGN CAPACITY E. TRIBUTARY DRAINAGE SYSTEM Preface: Stormwater from most of the project will be directed through a conveyance system which transports the flow to an open wet pond. This conveyance system will be principally overland flow discharging to piped drain systems. Most of the sediment carried by the drainage system is intended to be trapped in the catch basins. Maintenance of this system can play a major role in the long-term maintenance costs and the effectiveness of the stormwater system. Inspection: The tributary drainage system should be periodically inspected to assure that it is operating as intended, and that its carrying capacity has not been diminished by accumulations of debris and sediment or other hydraulic impediments. On piped systems the inlets must be inspected to ensure the rims are set at the proper elevation to optimize flow entry and are not clogged with leaves or other debris. The inlet basins are normally equipped with sumps which will remove large sediment particles from the flow stream with hooded outlets. The level of sediment in the sumps should be checked to assure their effectiveness. Pipelines connecting the inlets should be checked to determine if siltation is occurring. This will be most critical on drain lines laid at minimal slopes. This can usually be accomplished by a light and mirror procedure. In some projects most of the stormwater is carried in open swales, channels, or ditches. These conveyance channels may be rip rapped or vegetated, depending on the gradient and expected flow velocities. These facilities must be inspected to insure debris or sedimentation does not reduce their carrying capacity. Excess vegetative growth must also be noted. The surface protection for the channels, either stone or vegetation, must be inspected to insure its integrity. Any areas subject to erosion should be noted. JN3203 Inspection & Maintenance Manual August 2013 Page 7 Brunswick Layover Facility Brunswick, ME

Maintenance: Maintenance of the storm drainage system must assure that it continues to serve its design function on a long term basis, and that its operation does not transport excessive sedimentation to any downstream detention pond, filters, or the receiving waters. Elevations on the rim of catch basins should be adjusted as needed to assure optimal water entry. Depending on the frost susceptibility of the soil, the rims may become elevated over time causing flow to circumvent the inlet. When the filter bag in an inlet restricts capacity and is coated with silt or other deleterious materials, the bag should be removed and Catch basin cleaning would normally be accomplished with vacuum trucks contracted as a maintenance service for the retail center. The removed material must be disposed of at an approved site for such materials. If sediment in the pipeline exceeds 20% of the diameter of the pipe, it should be removed. This may be accomplished by hydraulic flushing, or by mechanical means. If hydraulic flushing is used the downstream conditions should be analyzed. In general a sump or sediment trap should be used where it can be flushed into the detention pond, since it will reduce pond volume and hasten the time when it must be cleaned. A WELL STABILIZED VEGETATED SWALE SHOWS LITTLE SIGNS OF EROSIVE VELOCITIES OR FLOWS. THIS SWALE ALSO FUNCTIONS AS A POND SPILLWAY Frequency: The piped drainage system should be inspected on an annual basis. Adjustment of inlet rim elevations should be on an as needed basis. Cleaning catch basin sumps and pipelines will depend on the rate of accumulation. Typically, catch basin sumps should require little maintenance because of the filter bags. Pipeline cleaning schedules will be more variable Maintenance Personnel: By Owner. Special Services: The owner may elect to contract with an independent agent for cleaning of replacement of filter bags, catch basins, sumps, and pipelines. Remedial source control measures may be performed by the owner or an outside service depending upon the nature of the particular situation. Comments: Maintenance of inlets is critical on this project. F. VEGETATED SWALES Preface: Vegetated swales are often used to convey stormwater. Swales can be intended to be: 1. Mowed and maintained 2. Reverted to wetlands 3. Naturalized JN3203 Inspection & Maintenance Manual August 2013 Page 8 Brunswick Layover Facility Brunswick, ME

Inspection: Swales should be inspected for erosion and sedimentation. Maintenance: Eroded or silted channels need to be repaired when discovered. If erosion is a problem, the swale design should be examined. Likewise, if the situation is a continued problem, the upgradient conditions should be reassessed. Frequency: It is recommended vegetated swales be inspected quarterly until vegetation is established and a year after installation. Thereafter, if no problems have been noticed, the frequency can be increased to one year. VEGETATED SWALE UNDER CONSTRUCTION WITH HAY BALE CHECK DAM TO REDUCE VELOCITIES Design Guidelines: The vegetated swale should consider channel cover at the time of concentration as well as several years after construction. Design computations should state the assumed channel of vegetation and provide the basis for the Manning s or other roughness coefficient and for design. Applicability: The Brunswick Layover Facility will include vegetated swales as well as open armored channel systems. A WELL STABILIZED VEGETATED SWALE SHOWS LITTLE SIGNS OF EROSIVE VELOCITIES OR FLOWS. THIS SWALE ALSO FUNCTIONS AS A POND SPILLWAY JN3203 Inspection & Maintenance Manual August 2013 Page 9 Brunswick Layover Facility Brunswick, ME

G. POND LINING Preface: The pond will have low permeability clay, soil/emulsion mix, or linear low density polyethylene liner intended to minimize or avoid exfiltration of the storm water to the underlying ground groundwater resource. The liner is shown on the design drawings. The record drawings for the project will reflect the type of liner installed for the project. Inspection: Observations of substantial water level variations could indicate pond leakage. Repairs could be made using a material called ESS 13 which is a vegetable emulsion that expands during degradation and acts similar to a radiator sealant. Maintenance: Avoid excavation of original sidewall areas or pond bottom areas. Do not install new below water piping without proper watertight boots, Ripley s Dams, or seals. H. SORBENT BOOMS Preface: During construction, sorbent booms will be installed in the catch basins within pavement areas. The intent of these is to absorb oil and runoff from new pavement surfaces. These will be removed and replaced when construction of the project is complete and should be inspected quarterly for the first year and annually thereafter. Inspection: The sorbent boom should be raised out of the inlet, inspected, and replaced if necessary. Inspection should occur for the first year and annually thereafter concurrent with the catch basin cleaning. Recommendation: It is recommended this project have additional sorbent booms or pillows onsite in the event of an unexpected spill or if oil sheen is observed frequently on any inlet. Maintenance: The inspection and replacement should be conducted as part of a third party O&M contract and require disposal of used sorbent booms as special wastes. I. PARKING LOT CLEANING To protect the catch basin sediment bags, underground storage, and pretreatment, sweeping of the paved parking lot at mid winter and spring and that power washing with an appropriate vacuum/power wash vehicle be once a year is recommended. Maintenance: It is recommended this service be done by maintenance staff or contract to an outside firm that has the equipment for sweeping and power washing. J. LITTER Litter should be removed as a matter of course by workers and a part of the grounds maintenance contract. K. SUMMARY CHECKLIST The above described inspection and maintenance items have been summarized on a checklist attached hereto as Appendix C. JN3203 Inspection & Maintenance Manual August 2013 Page 10 Brunswick Layover Facility Brunswick, ME

IV. PROGRAM ADMINISTRATION A. GENERAL A reliable administrative structure must be established to assure implementation of the maintenance programs described in the foregoing section. Key factors that must be considered in establishing a responsive administrative structure include: 1. Administrative body must be responsible for long-term operation and maintenance of the facilities. 2. Administrative body must have the financial resources to accomplish the inspection and maintenance program over the life of the facility. 3. The administrative body must have a responsible administrator to manage the inspection and maintenance programs. 4. The administrative body must have the staff to accomplish the inspection and maintenance programs, or must have authority to contract for the required services. 5. The administrative body must have a management information system sufficient to file, retain, and retrieve all inspection and maintenance records associated with the inspection and maintenance programs. If any of the above criteria cannot be met by the entity assigned inspection and maintenance responsibilities, it is likely that the system will fail to meet its water quality objectives at some point during its life. While each of the above criteria may be met by a variety of formats, it is critical to clearly establish the assigned administrative body in a responsible and sustainable manner. B. RECORD KEEPING Records of all inspections and maintenance work accomplished must be kept and maintained to document facility operations. These records should be filed and retained for a minimum 5-year time span. The filing system should be capable of ready retrieval of data for periodic reviews by appropriate regulatory bodies. Where possible, copies of such records should also be filed with the designated primary regulatory agency for their review for compliance with permit conditions. Typical inspection and maintenance record forms are attached hereto as Appendix B. C. CONTRACT SERVICES In some instances or at specific times, the Maintenance Personnel may not have the staff to conduct the required inspection and/or maintenance programs as outlined in this document. In such cases, the work should be accomplished on a contractual basis with a firm or organization that has the staff and equipment to accomplish the required work. The service contract for inspection and maintenance should be formal, well written legal document which clearly defines the services to be provided, the contractual conditions that will apply, and detailed payment schedules. Liability insurance should be required in all contracts. JN3203 Inspection & Maintenance Manual August 2013 Page 11 Brunswick Layover Facility Brunswick, ME

APPENDIX A Sample Inspection Logs

BRUNSWICK LAYOVER FACILITY BRUNSWICK, MAINE STORMWATER MANAGEMENT WATER QUALITY WATER QUALITY FACILITY ANNUAL INSPECTION & MAINTENANCE LOG FACILITY: YEAR: LOCATION: CONTRACTOR: FUNCTION: INSPECTOR: DATE OF INSPECTION: ITEM IDENTIFICATION DESCRIPTION OF CONDITIONS MAINTENANCE ACCOMPLISHED DATE OF MAINTENANCE GENERAL COMMENTS:

FACILITY: YEAR: BRUNSWICK LAYOVER FACILITY BRUNSWICK, MAINE STORMWATER MANAGEMENT WATER QUALITY FILTER & DETENTION POND MONTHLY INSPECTION & MAINTENANCE LOG LOCATION: CONTRACTOR: FUNCTION: OVERFLOW WEIR MONTH DAY INSPECTOR WATER DEPTH CLEAR DEBRIS WEIR CONDITION JANUARY FEBRUARY MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER LIST SPECIAL MAINTENANCE UNDERTAKEN:

FORE BAY SUMP EST. DEPTH SED. REMOVED? Y/N EST. VOL. CY WHERE DISPOSED OF STRUCTURAL CONDITION BRUNSWICK LAYOVER FACILITY BRUNSWICK, MAINE STORMWATER MANAGEMENT WATER QUALITY WATER QUALITY FACILITY SEMI-ANNUAL INSPECTION & MAINTENANCE LOG SEMI-ANNUAL INSPECT 1.2 FACILITY: DATE: LOCATION: INSPECTOR: FUNCTION: WEIR CONDITION: OUTLET CONDITION CONTROL STRUCTURE: DESCRIBE CONDITIONS FOUND & MAINTENANCE ACCOMPLISHED:

APPENDIX B Permits for Project (To be Added at a Subsequent Time)

APPENDIX C Summary Checklist Inspection and Maintenance

Stormwater Management System Maintenance Program Summary Checklist Frequency Semi- Item Commentary Month Quarterly Annual Pond Overflow Inspect spillways and remove debris. Maintenance conducted on as needed basis. Control Structures Inspect outlet control to assure it maintains its hydraulic characteristics. Inspect inlets for blockage. X Filter Berms Inspect berms for sags, sloughing, or erosion and Mow undesirable tree growth. X Summer Mow berm slopes to control vegetation repair structure flaws upon identification. Vegetation in Ponds Observe extent of vegetation in fall. Cut above ice level in winter - remove. Stormwater Inlets Series Tributary Drainage Vegetated Swales Pond Lining Sorbent Booms Parking Lot Cleaning Litter Stormwater inlets allow flow entry from a surface swale to a piped system. Entry may or may not be equipped with a bar rack. Inspect entry for debris accumulation. Remove debris to allow unimpeded entry. Lawn clippings and leaves should be removed from yard areas. Inspect to assure that the carrying capacity has not been diminished by debris, sediment or other hydraulic impediments. Inspect for erosion and sedimentation; repair as discovered; check design and upgradient conditions as indicated by needed repairs. Inspect for water level variations which could indicate pond leakage. Sorbent boom should be raised out of the inlet, inspected, and replaced if necessary. Parking lot be swept at mid winter and spring. Power washing with an appropriate vacuum/power wash vehicle be done once a year. Litter should be removed daily. X X (initial work) X X For 1 st 12 months X Annual X X X X Clearing X X After 1 st year X Long Term

ATTACHMENT F Urban Impaired Stream Watershed Map

miles km 1 2