Loading...
HomeMy WebLinkAboutSEP2000-00015 Grade 15,000 cy Corrections to Utility Instalation - SEP Determinations - 2/1/2000 I oN_STgTF MASON COUNTY BPS C �� DEPARTMENT OF COMMUNITY DEVELOPMENT M O S NUPlanning Division 0 N Y P O Box 578, Shelton, WA 98584 of 1864 (360)427-9670 MITIGATED DETERMINATION OF NONSIGNIFICANCE (WAC 197-11-350) SEP2000-00015 Description of Proposal: To grade 15,000 cubic yards on a 16 acre site. The proposed grading project is to correct and improve stormwater, utility installation, paving and pond excavation. Proponent: ROBERT DRESSEL Site Address (If Assigned): 431 NE LOG YARD RD BELFAIR Directions to Site: The site is located at the end of Log Yard Road. Parcel Number: 123211001070 Legal Description: TR 7 OF N1/2 NE Lead Agency: Mason County The Lead Agency for this proposal has determined that it does not have a probable significant adverser impact on the environment. An Environmental Impact Statement (EIS) is not required under RCW 43.21 C.030(2)(c). This decision was made after review of a completed Environmental Checklist and other information on file with the Lead Agency. This information is available to the public upon request. MITIGATED MEASURES ARE ATTACHED. Please contact y Ne ee at ext. 26-5 with any questions. This DNS is issue nder 197-1 1 0(2) the Lead Agency will not act on this proposal for 14 days from the date below. Comment u e u t d b 116/00. 66nWQrejof Responsible Official Date SKOKOMISH TRIBE (2) HCCC DOE FPD #ZCf�__J WDF&W MCPW DNR APPLICANT MITIGATED DETERMINATION OF NONSIGNIFICANCE (WAC 197-11-350) SEP2000-00015 CONDITIONS OF THIS DETERMINATION 1) Residential developers and individuals shall be required to control erosion during construction. Removal of vegetation should be minimized and any areas disturbed should be restored to prevent erosion and other environmental impacts.X 2) Water quality is not to be degraded to the detriment of the aquatic environment as a result of this project. X 3) Emergency vehicle apparatus access roads shall conform with the requirements of the Uniform Fire Code and Mason County Title 16. If the access road cannot conform, special conditions will be placed on any building permit issued on property that is served by a non-conforming access road. Contact the Mason County Fire Marshal for details. 4) All future development of the proposed site will be subject to the conditions that are listed. However, this does not exempt future proposals from further review through the SEPA process. A MASON COUNTY PUBLIC WORKS DIRECTORkOUNTY ROAD ENGINEER Shelton,Washington 98584 DATE: January 14, 2000 INTER-DEPARTMENTAL COMMUNICATIONS TO: Randy Neff, DCD - Planner FROM: Alan A. Tahja, P/W- Co. Hydr. Engr. DCD WO#000002 SUBJ: Stormwater Report Review NAME: Robert Dressel GRD99-0028 Randy, The Stormwater Site Plan developed for the proposed North Mason Fiber Company in Belfair has been received and reviewed by Public Works and found to comply with current standards and good engineering practice for this time and place. The Temporary Erosion and Sediment Control (TESC)plan on sheet 15 of the plan sheets should be required to be followed. Included in the TESC is a requirement (#14 under Drainage Notes) that a performance Covenant or surety shall be required. At this time Public Works is relying on the grading permit requirements and penalties to stand for the financial liability element of a Large Parcel Permanent Water Quality Control Plan required in Ecology's Technical Manual. The proposed stormwater plan and grading plan appear acceptable as submitted. An Operation and Maintenance (O&M) Covenant is required under the County's surface water management ordinance to be created to cover the proposed stormwater control features. Attached please find a copy of the form Mason County is employing to satisfy this requirement. Please forward a copy of the O&M Covenant to the owner or their engineer for completion, recording, and delivery to Public Works for future monitoring and administration. Please feel free to contact me at County extension 461 if you have any questions regarding this department's review or these comments. Sincerely, JL Alan A. Tahja Encl: O&M Covenant form File: H:\WP\STRMWTR\REVIEWS\Dressel-idc.doc MASON CO. ENVIRONMENTAL CHECKLIST A. BACKGROUND 1 . Name of proposed project, if applicable : North Mason Fiber Company 2 . Name of applicant : Mr. Robert Dressel 3 . Address and phone number of applicant and contact person: P.O. Box 275 N.L. Olson and associates, Inc. Belfair, WA 98528 2453 Bethel Avenue (360) 275-0228 Port Orchard, WA 98366 (360) 876-2284 Norman L. Olson, P.E. 4 . Date checklist prepared: December 1, 1999 S . Agency requesting checklist : Mason County Department of Community Development 6 . Proposed timing or schedule (including phasing, if applicable) : The project is anticipated to be begin construction during the 2000 construction season. 7 . Do you have any plans for future additions, expansions, or further activity related to or connected with this proposal? If yes, explain. None known. 8 . List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal . None known. 1 MASON CO. ENVIRONMENTAL CHECKLIST 9 . Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain . No. 10 . List any governmental approvals or permits that will be needed for your proposal , if known. Grading Permit, Storm Drainage approval, SEPA approval, Fire Control System approval . 11 . Give brief, complete description of your proposal , including the proposed use and the size of the project and site . There are several questions later in this checklist that ask you to describe certain aspects of your proposal . You do not need to repeat those answers on this page . (Lead agencies may modify this form to include additional specific information on project description) . The Applicant proposes to construct an additional 7 . 69 acres of new pavement area, along with two stormwater retention ponds, one fire control storage pond and two biofiltration swales . Of the total 25 . 56 acre site, the improvement work will take place on only 16 . 68 acres, within the north and southeast portions of the property, or Basins A and B. The site is divided into three separate areas . No improvements are anticipated to the southwest portion of the property or Basin C. Basin A, located in the north portion of the property consists of 8 .71 acres and is presently cleared with approximately 2 .71 acres of pavement. The proposed improvements to the north area include 2 .77 areas of new pavement area, a retention pond and biofiltration Swale, a fire control storage pond and pipe system, 0 . 64 acres of existing third growth forest and/or brush and 0 .43 areas of grass in fair condition. 2 MASON CO. ENVIRONMENTAL CHECKLIST Basin B, located in the southeast portion of the property consists of 7 . 97 acres and is currently cleared with approximately 0 .22 acres of pavement area with buildings and graveled surface. The proposed improvements to the southeast area include 4 . 38 acres of additional new pavement, a storm retention pond and biofiltration swale . There are 0 . 53 acres of existing third growth forest and/or brush and 0 . 25 areas of grass in fair condition. Basin C, located in the southwest portion of the property consists of 8 . 88 acres, is developed and will remain in its current condition. This area consists of approximately 7 . 55 acres of pavement and 1 .33 acres of third growth forest and/or brush. 12 . Location of the proposal . Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range or boundaries of the site (s) . Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available . While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist . The total 25 . 56 acre site is located east of State Highway 3 with access from Log Yard Road, and west of Old Belfair Highway, in a portion the west 1700 feet of the North Half of the Northeast Quarter of Section 21, Township 23 North, Range 1 East, Willamette Meridian in Mason County, Washington. 3 MASON CO. ENVIRONMENTAL CHECKLIST B . ENVIRONMENTAL ELEMENTS 1 . EARTH a . General description of the site (circle one) : Flat, Rolling, hilly, steep slopes , mountainous, other . The site is divided into three areas . The southwest 8 . 88 acres slopes with an average declivity of 1 . 5% and the southeast 7 . 97 acres slopes 0 . 32 acres slopes with an average declivity of 1 . 0o, and the north 8 . 71 acres slopes with an average declivity of 5 . 0o. b. What is the steepest slope on the site (approximate percent slope) ? The steepest slope on the site appears to be approximately 66 percent. This steep occurs at the southeast property boundary with the majority of the southeast basin at a 1 . 50 slope. Said steep slope covers about 1000 sq. ft . C . What general types of soils are found on the site (for example, clay, sand, gravel, peat , much) ? If you know the classification of agricultural soils specify them and note any prime farmland. Soils on the site are classified as Everett loamy sand. (Ed) d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe . No. 4 MASON CO. ENVIRONMENTAL CHECKLIST e . Describe the purpose, type and approximate quantities of any filling or grading proposed. Indicate source of fill . The majority of the site is has been cleared or is paved, with some pasture grass, brush and some trees around the perimeter. Approximately 850 of the 16 . 68 acre improvement area will be graded for pavement, utility installation (relocation) and retention or fire control storage pond construction. Grading with no importation or exportation is anticipated. Approximately 15, 000 cubic yards of excavation will occur on site . f . Could erosion occur as a result of clearing, construction or use? If so, describe . Yes . Erosion could occur during construction but Erosion Control measures will be implemented during that time . g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings) ? Approximately 71 percent of the 25 . 56 acre site will be covered with impervious surfaces associated with buildings and asphalt. Currently the site is 41 percent impervious with existing buildings and asphalt pavement. h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: All requirements of Mason County Department of Public Works for Temporary Erosion / Sedimentation Control (TESC) Plan will be applied to the maximum extent possible during and after construction, to preserve the quality of stormwater leaving the site. To minimize the impacts due to land disturbing activities on the site, construction will begin in the spring. Soil exposure will be kept to a minimum until all erosion/sedimentation measures are in place. The erosion/sedimentation control system will continue to be maintained and repaired until the site is stabilized to assure continued performance of the intended function on the site. 5 MASON CO. ENVIRONMENTAL CHECKLIST 2 . AIR a. What types of emissions to the air would result from the proposal (i .e . , dust, automobile, odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities, if known. Dust and diesel exhaust will be produced on site during construction. Auto and equipment utilized by the owner/tenants emissions after the completion of the project. b. Are there any off-site sources of emissions or odor that may affect your proposal? No. C . Proposed measures to reduce or control emissions or other impacts to air, if any: Construction vehicles will conform to all applicable Washington State Emission Control requirements. All emissions will comply with the requirements put forth in the Puget Sound Air Quality Authority. Any burning during construction will be conducted with a burning permit with Fire Department coordination. 3 . WATER a. Surface : 1) Is there any surface water body on or in the immediate vicinity of the site (including year-round and seasonal streams, saltwater, lakes, ponds, wetlands) ? If yes, describe type and provide names . If appropriate, state what stream or river it flows into. None known. 6 V 4 MASON CO. ENVIRONMENTAL CHECKLIST 2) Will the project require any work over, in, or adjacent to (within 200 feet) the described ' waters? If yes, please describe and attach available plans . No. 3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material . It is anticipated that no fill material will be removed from the site. 4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose and approximate quantities, if known. No. 5) Does the proposal lie within a 100-year flood plain? If so, note locations on the site plan. No. 6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge . No. The proposal involves the use of a storm infiltration system. b. Ground: 1) Will ground water be withdrawn, or will water be discharged to ground water? Give general description, purpose and approximate quantities, if known. Yes. A storm infiltration system has been designed for the 100-year, 24-hour storm event. The project generates 6 .12 ac-ft of total runoff volume. 7 MASON CO. ENVIRONMENTAL CHECKLIST 2) Describe waste material that will be discharged into the ground from septic tanks or other sources , if any (for example : Domestic sewage ; industrial, containing the following chemicals . . . , agricultural ; etc . ) Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable) , or the number of animals or humans the system (s) are expected to serve . None . The applicant currently utilizes a SaniCan for the office and will continue to do so. C . Water Runoff (including storm water) : 1) Describe the source of runoff (including storm water) and method of collection and disposal, if ariy (including quantities, if known) . Where will this water flow? Will this water flow into other waters? If so, describe . The stormwater runoff generated from the site improvements will be collected and conveyed through a system of biofiltration swales for treatment prior to discharging into the retention pond and infiltrating as described above . Please refer to the Final Storm Drainage analysis dated November 29, 1999 . 2) Could waste .material enter ground or surface waters? If so, general describe . Waste material associated with impervious surface runoff will enter the ground through the infiltration system proposed, but the Biofiltration swale will be responsible for providing the required water quality. d. Proposed measures to reduce or control surface ground and runoff water impacts, if any. Water quality / quantity mitigation efforts will be reviewed and approved by Mason County. 8 V MASON CO. ENVIRONMENTAL CHECKLIST 4 . PLANTS a. Check or circle types of vegetation found on the site : X Deciduous tree: Alder, maple, aspen, other X Evergreen tree: fir, cedar, pine, other X Shrubs X Grass X Pasture crop or grain wet soil plants : cattail, buttercup, bulrush, skunk cabbage, other water plants : water lily, eelgrass, milfoil, other other types of vegetation b. What kind and amount of vegetation will be removed or altered? The majority of the vegetation on the site will altered or removed. Approximately 29% of the site will be grass or native, 71 % will be pavement and buildings. C . List threatened or endangered species known to be on or near the site . No threatened or endangered species are known or suspect to occur on the site. d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: No landscaping plan will be submitted in conjunction with the proposal. 9 MASON CO. ENVIRONMENTAL CHECKLIST 5 . ANIMALS a . circle any birds and animals which have observed on or near the site or are known to be on or near the site : birds : hawk, heron, eagle, songbirds, other. mammals : deer, bear, elk, beaver, other . fish: bass, salmon, trout, herring, shellfish, other. b. List any threatened or endangered species known to be on or near the site . None known. - C . Is the site part of a migration route? If so, explain. No. d. Proposed measures to preserve or enhance wildlife, if any: None 6 . ENERGY and NATURAL RESOURCES a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project 's energy needs? Describe whether it will be used for heating, manufacturing, etc . Electricity is utilized for all energy needs . Natural gas via portable tanks my be practical in the future. b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe . No. c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any: Building construction to comply with Washington State Energy Conservation Codes. 10 MASON CO. ENVIRONMENTAL CHECKLIST 7 . ENVIRONMENTAL HEALTH a . Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe . Minimal risk of spills and fire during construction. 1) Describe special emergency services that might be required. None other than the normal Police and Fire Department. 2) Proposed measures to reduce or control environmental health hazards, if any: None. b. Noise 1) What types of noise exist in the area which may affect your project (for example : traffic, equipment, operations, other) ? Noise from Log Yard Road, State Highway 3 and the surrounding properties are minimal and will not impact the proposal . 2) What types and levels of noise would be created by or associated with the project on a short term or long term basis (for example : traffic, construction, operation, other) ? Indicate what hours noise would come from the site . Short term noise will be generated by construction equipment during standard business hours . Additional noise from the proposed business during the day and evening hours. 3) Proposed measures to reduce or control noise impacts, if any: None. 11 MASON CO. ENVIRONMENTAL CHECKLIST 8 . LAND and SHORELINE USE a. What is the current use of the site and adjacent properties? The site is currently developed commercial . Surrounding properties are undeveloped commercial . b. Has the site been used for agriculture? If so, describe : Not known. C . Describe any structures on the site . Office building and other outbuildings. d. Will any structures be demolished? If so, ,what? No. e . What is the current zoning classification of the site. a(, The current zoning classification for the site is Commercial. f . What is the current comprehensive plan designation of the site? Mason County Comprehensive Plan designates the site as h# Commercial. g. If applicable, what is the current shoreline master program designation of the site? N/A. h. Has any part of the site been classified as an "environmentally sensitive" area? If so, specify. No. i . Approximately how many people would reside or work in the completed project? Approximately 6 people will work at the completed project and none will reside. 12 MASON CO. ENVIRONMENTAL CHECKLIST j . Approximately how many people would the completed project displace? None. k. Proposed measures to avoid or reduce displacement impacts, if any: None. 1 . Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: The proposal will comply with all applicable Mason County Land Use Regulations. 9 . HOUSING a . Approximately how many units would be provided, if any? Indicate whether high, middle, or low income housing. None. b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low income housing. None. c . Proposed measures to reduce or control housing impacts, if any: None. 10 . AESTHETICS a. What is the tallest height of any proposed structure (s) , not including antennas; what is the principal exterior building material (s) proposed? N/A. 13 MASON CO. ENVIRONMENTAL CHECKLIST b. What views in the immediate vicinity would be altered or obstructed? None. C . Proposed measures to reduce or control aesthetic impacts, if any: None. 11 . LIGHT and GLARE a. What type of light or glare will the proposed produce? What time of day would it mainly occur? - None. b. Could light or glare from the finished project be a safety hazard or interfere with views? No. C . What existing off-site sources of light or glare may affect your proposal? None . d. Proposed measures to reduce or control light and glare impacts, if any: None. 12 . RECREATION a. What designated and informal recreational opportunities are in the immediate vicinity? N/A. b. Would the proposed project displace any existing recreational uses? If so, describe . No. 14 MASON CO. ENVIRONMENTAL CHECKLIST C . Proposed measure to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: None. 3 . HISTORIC and CULTURAL PRESERVATION a . Are there any places or objects listed on, or proposed for, national, state, or local preservation registers known to be on or next to the site? If so, generally describe . No. b. Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site . None. C . Proposed measures to reduce or control impacts, if any: None. 14 . TRANSPORTATION a . Identify public streets and highways serving the site, and describe proposed access to the existing street system. Show on site plans, if any: Site access will be provided from State Highway 3 and Log Yard Road. b. Is the site currently served by public transit? If not, what is the approximate distance to the nearest transit stop? No. C . How many parking spaces would the completed project have? How many would the project eliminate? N/A. 15 MASON CO. ENVIRONMENTAL CHECKLIST d. Will the proposal require any new roads or streets, or improvements to existing roads or streets, not including driveways? If so, generally describe (indicate whether public or private) . No. e . Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe . The project will utilize railway for transportation of materials to be stored on site. The object is to use rail and the site for a material transfer area. f . How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volume would occur. Approximately 224 vehicular trips per day is anticipated. g. Proposed measures to reduce or control transportation impacts, if any: None . 15 . PUBLIC SERVICES a. Would the project result in an increased need for public services (for example : fire protection, police protection, health care, schools, other) ? If so, generally describe . No. b. Proposed measures- to reduce or control direct impacts on public services, if any. None. 16 MASON CO. ENVIRONMENTAL CHECKLIST 16 . UTILITIES a . Circle utilities currently available at the site : Electricity, natural gas, water, refuse service, telephone, sanitary sewer, septic system, other. Cable TV 17 . SIGNATURE The above answers are true and complete to the best of knowledge . I understand that the lead agency is relying on them to make its decision. gnat Si - e 7 l C_� o an L.- Ol on, P .E . Date Submitt d 17 ESA LISTED SALMONIDS CHECKLIST Applicant Information Project Information Name Name Phone Location Description This worksheet was designed to help project proponents and government agencies identify when a project needs further analysis regarding adverse effects on ESA (Endangered.--Species Act) listed salmonids . Salmonids are salmon, trout and chars , e.g. bull trout . For our purposes , "ESA listed salmonids" is defined as fish species listed as endangered, threatened or being considered for listing . If ESA listed species are present or ever were present in the watershed where your project will be located, your project has the potential for affecting them, and you need to comply with the ESA. The questions in this section will help determine if the ESA listings will impact your project. The Fish Program Manager at the appropriate Department of Fish and Wildlife (DFW) regional office can provide information for the following two questions 1 . Are ESA listed salmonids currently present in the watershed in whi�,ch your project will be located? Yes No Please describe . 4'6oD (f.4NAL 2 . Has there ever been an ESA listed salmonid stock present in this watershed? Yes No Uncertain Please describe . If you answered "yes" to either of the above questions, you should complete the remainder of this checklist. September 1999 1 PROJECT SPECIFICS: The Questions in this section are specific to • the project and vicinity. 1 . Name of watershed: V�R I 14 /I SLp 2 . Name of nearest waterbody: 1601) C, piAl 3 . What is the distance from this project to the nearest body of water? Often a buffer between the project and a stream can reduce the chance of a negative impact to fish. 4 . What is the current land use between the project and the potentially affected water body (parking lots, farmland, etc) ? OVA IK /RESIDIFN7/AL 5 . Is the project above a: • natural permanent barrier (waterfall) Yes No ? • natural temporary barrier (beaver pond) Yes No z • man-made barrier (culvert, dam) Yes No 7 • other (explain) : 6 . If yes, are there any resident salmonid populations above the blockage? Yes No Don' t know, 7 . What percent of the project will be impervious surface (including pavement & roof area) ? 70 1 f1 September 1999 2 FISH MIGRATION: The following questions will help determine if this project could interfere with migration of adult and juvenile fish. Both increases and decreases in water flows can affect fish migration. 1 . Does the project require the withdrawal of : i . Surface water? Yes No_k Amount Name of surface water body ii . Ground water? Yes_ No Amount From where Depth of well 2 . Will any water be rerouted? Yes No Lam' If yes , will this require a channel change? 3 . Will there be retention or detention ponds? Yesje:::�'No If yes, will this be an infiltration pond or a surface discharge to either a municipal storm water system or a surface water body? /Vo If to a surface water discharge, please give the name of the waterbody.. N6A/E /il/ �L y'lz R-r�Z /,V7-0 4 . Will this project require the building of new roads? Yes No L—' Increased road mileage may affect the timing of water reaching a stream and may impact fish habitat. 5 . Are culverts proposed as part of this project? Yes No��' 6 . Will topography changes affect the duration/direction of runoff flows? Yeses No If yes , describe the changes . PAC141)-y Ib bf CD417-P LtC V P 7 . Will the project involve any reduction of the floodway or floodplain by filling or other partial blockage of flows? Yes No If yes , how will the loss of flood storage be mitigated by your project? September 1999 3 S WATER QUALITY: The following questions will help determine if this project could adversely impact water quality. Such impacts can cause problems for listed species. Water duality can be made worae by runoff from impervious surfaces, altering water temperature, discharging contaminants, etc. 1 . Do you know of any problems with water quality in any of the streams within this watershed? Yes No If yes , describe. 2 . Will your project either reduce or increase shade along or over a waterbody? Yes No 1-� Removal of shading vegetation or the building of structures such as docks or floats often result in a change in shade. 3 . Will the project increase nutrient loading or have the potential to increase nutrient loading or contaminants (fertilizers , other waste discharges, or runoff) to the waterbody? Yes No '-- 4 . Will turbidity be increased because of construction of the project or during operation of the project? Yes Now In-water or near water work will often increase turbidity. 5 . Will your project require long term maintenance, i . e . bridge cleaning, highway salting, chemical sprays for vegetation management, clearing of parking lots? Yes No I-- If yes, please describe . September 1999 4 VEGETATION: The following questions are designed to determine , if the project will affect riparian vegetation, thereby, adversely impacting salmon. 1 . Will the project involve the removal of any vegetation from the stream banks? Yes No If yes, please describe the existing conditions , and the amount and type of vegetation to be removed. 2 . If any vegetation is removed, do you plan to re-plant? Yes No P" If yes , what types of plants will you use? September 1999 5 FINAL STORM DRAINAGE ANALYSIS FOR: NORTH MASON FIBER COMPANY CLIENT: NORTH MASON FIBER COMPANY P.O. BOX 275 BELFAIR, WA 98528 (360) 275-0228 ATTN: MR. ROBERT DRESSEL PREPARED BY: N.L. OLSON AND ASSOCIATES, INC . 2453 BETHEL AVE. SE PORT ORCHARD, WA 98366 (206) 876-2284 L50 99 WAS �OtvAL / W/gy December 10, 1999 e { NORTH MASON FIBER COMPANY TABLE OF CONTENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii TABLE OF CONTENTS I . INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PG. 1 II . UPSTREAM ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PG. 2 III . DOWNSTREAM ANALYSIS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PG. 2 IV. DESIGN CALCULATIONS: A. PARAMETERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PG. 5 B. BASIN A STORM WATER FAC;LITY DESIGN. . . . . . . . . . . . . . . . PG. 9 1 . DEVELOPED CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . PG. 9 2 . DESIGN INFILTRATION RATE . . . . . . . . . . . . . . . . . . . . . PG. 10 3 . RETENTION/INFILTRATION POND DESIGN. . . . . . . . . . . PG. 10 4 . BIOFILTRATION SWALE DESIGN. . . . . . . . . . . . . . . . . . . PG. 11 5 . EMERGENCY OVERFLOW SPILLWAY DESIGN. . . . . . . . . . . PG. 12 C. BASIN B STORM WATER FACILITY DESIGN. . . . . . . . . . . . . . . . PG. 13 1 . DEVELOPED CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . PG. 13 2 . DESIGN INFILTRATION RATE. . . . . . . . . . . . . . . . . . . . . PG. 14 3 . RETENTION/INFILTRATION POND DESIGN. . . . . . . . . . . PG. 15 4 . BIOFILTRATION SWALE DESIGN. . . . . . . . . . . . . . . . . . . PG. 16 5 . EMERGENCY OVERFLOW SPILLWAY DESIGN. . . . . . . . . . . PG. 17 6 . OVERFLOW INFILTRATION TRENCH DESIGN. . . . . . . . . . PG. 17 i LIST OF FIGURES FIGURE 1 - VICINITY MAP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PG. A-1 FIGURE 2 - SCS SOILS MAPPING. . . . . . . . . . . . . . . . . . . . . . . . . . PG. A-2 FIGURE 3 - HYDROLOGIC SOIL GROUP (TR-55) . . . . . . . . . . . . . . PG. A-3 FIGURE 4 - RUNOFF CURVE NUMBERS . . . . . . . . . . . . . . . . . . . . . . . PG. A-4 FIGURE 5 - "n" AND "k" VALUES . . . . . . . . . . . . . . . . . . . . . . . . . . PG. A-5 FIGURE 6 - 2-YEAR 24-HOUR PRECIPITATION. . . . . . . . . . . . . . . PG. A-6 FIGURE 7 - 100-YEAR 24-HOUR PRECIPITATION. . . . . . . . . . . . . PG. A-7 FIGURE 8 - DEVELOPED CONDITIONS MAP. . . . . . . . . . . . . . . . . . . PG. A-8 FIGURE 9 - D.O.E . INFILTRATION RATE TABLE . . . . . . . . . . . . . PG. A-9 ii I. INTRODUCTION• The North Mason Fiber Company is located near Belfair, Washington, in Mason County, west of and ajacent to Log Yard Road between State Highway 3 to the east and Old Belfair highway to the west . The 25 . 56 acre site is situate in the Northeast Quarter of Section 21, Township 23 North, Range 1 West, Willamette Meridian in Mason County, Washington (See Figure 1 in Appendix A) . The subject property is currently developed commercial with pavement, an office and a few outbuildings . The site is typicaly cleared but surounded with typical Puget Sound third growth timber stands of Douglas and Hemlock Fir, Cedar, Pine, Alder, and Maple . The under story consists of Rhododendrons, Ferns, Salal, and Blackberry. The USDA Soil Conservation Service classifies the site as primarily Everett soils (Hydrologic Group Ed) -with slopes 0 to 15 percent . Given the Everett soils the Curve Numbers will be assumed @ 'A' soil type, unless otherwise noted. The proposed improvements for this project include paving and grading along with construction of two retention/infiltration ponds and biofiltration swales for storm drainage quantity and quantity mitigation, and a fire control storage pond and pipe system. The runoff is divided into three separate systems as depicted on the Developed Conditions Map, Figure 8 in Appendix A, and- as described as follows : Drainage Basin A, consisting of 8 . 71 acres and is located in the north portion of the property. Retention Pond A will receive 6 . 55 acres of runoff, 5 . 48 acres from pavement and 0 . 64 acres from third growth forest and/or brush and 0 .43 acres from grass in fair condition. Of the 5 .48 acres of pavement, 2 . 71 acres is existing and 2 . 77 acres is proposed. 1 I . INTRODUCTION CONT'D. Drainage Basin B, consisting of 7 . 97 acres and is located in southeast portion of the property. Retention Pond B will receive 5 . 38 acres of runoff, 4 . 60 acres from pavement and 0 . 53 acres from third growth forest and/or brush and 0 . 25 acres from grass in fair condition. Of the 4 . 60 acres of pavement, 0 . 22 acres is existing and 4 . 38 acres is proposed. Of the 5 . 38 acres, 4 . 91 acres contributes runoff to the biofiltration swale, 4 . 38 acres from pavement and 0 . 53 acres from second growth forest and/or brush. Runoff from the remaining 2 . 59 acres of the 7 . 97 acre site, will sheet flow offsite. Drainage Basin C, consisting of 8 . 88 acres and is located in southwest portion of the property. The existing retention pond receives existing runoff from approximately 7 . 55 acres of pavement area and 1 . 33 acres from second growth forest and/or brush. This basin is developed and is not included as part of the improvement area or within this storm drainage analysis . II. UPSTREAM ANALYSIS: An upstream analysis for site concludes that the property is generally self contained, therefore no significant off-site runoff contribution is associated with the project site . III . DOWNSTREAM ANALYSIS: A downstream investigation of the site reveals that runoff to the north boundary continues down a sloped region prior to crossing under the railroad spur entering a swale which continues to the north to Union River and then south to Hood Canal . All runoff to the southeastly boundary continues down a sloped region along the railroad spur which continues to the south to Union River and Hood Canal . All runoff to the southwest is self contained within the existing pond area, with overflow to the south where runoff continues to flow along the railroad spur and overland to the Union River and south to Hood Canal . 2 III. DOWNSTREAM ANALYSIS CONT'D: The intent of the applicant is to reduce the maximum amount of runoff as possible from leaving the site . The two proposed retention/infiltration ponds are designed with emergency overflow spillways . Retention pond B is also designed with an underground infiltration overflow trench system. 3 z 0 H H a U a U z H W A y H IV. DESIGN CALCULATIONS A. PARAMETERS• 1 . The Water Quality / Water Quantity mitigation for the project site will be designed to meet the criteria set forth by the Washington Department of Ecology' s (DOE) Stormwater Management Manual for the Puget Sound Basin, except where modified herein as noted, and is as follows : * Water quantity mitigation for increased storm water runoff shall be performed by the use of storm water retention (infiltration) facility designed to meet the discharge requirements for 100 percent of the developed 100-year, 24-hour peak release rate design storm event . * Water quality mitigation for the site shall be performed by utilizing a biofiltration Swale designed for the 6-month, 24-hour peak release rate design storm event . * Runoff shall be computed using the SCS-based hydrograph method, Santa Barbara Urban Hydrograph (SBUH) , given a Type lA rainfall distribution. See Figure 4 and 5 in Appendix A for Runoff Curve numbers (CN) and "n" and "K" values used in Time calculations, respectively and Figures 6 and 7 for the 2-year and 100-year, 24-hour Precipitation and figure 6 for the 100-year Isopluvials respectively. * Design infiltration rates and sizing criteria shall meet the recommendations of the D.O. E . stormwater manual, Section III-3 (See Figure 13 in Appendix A) . * Technical requirements will be as per the Mason County Department of Public Work - Stormwater Division in conjunction with the Stormwater Management Manual for the Puget Sound Basin and using WATERWORKS SOFTWARE FOR HYDROLOGY (Version 4 . 11c) by Engenious Systems, Inc and OPEN CHANNEL FLOW MODULE, (Version 3 . 41) by Haestad Methods, Inc. 5 IV. DESIGN CALCULATIONS PARAMERTERS CONT'D. : 2 . Travel time (T-) for the SBUH Method will be determined as follows : T = 0 .42 (ns * L) °'Q / L (P_) 3.s * (sc) o.a (initial sheet flow @ 300 ' maximum distance) + SUM L / (V * 60) where : P, = 2-Year Rainfall Precipitation, IN. L = Flow Length, FT. V = Velocity, FPS = k (s_) '�21 ns = Manning' s sheet flow roughness coefficient (See Figure 8 in Appendix A) k = Time of Concentration Velocity Factor so = Slope, FT / FT 3 . Rainfall Precipitation for the project is as follows : PZ = 3 . 65 Inches @ 2-Year, 24-Hour Precipitation P6 = 2 . 34 Inches @ the 6-month, 24-Hour Precipitation (640 of 2-year Precipitation) Pioo = 7. 00 Inches @ 100-year, 24-Hour Precipitation (See Figures 6 and 7 in Appendix A) 6 IV. DESIGN CALCULATIONS PARAMERTERS CONT'D. : 4 . Emergency overflow spillway weirs (3 : 1 slopes) shall be designed to pass the developed 100-year storm event using the Santa Barbara Urban Hydrogra�h (SBUH) and the following formula, L = [Q100 / (3 . 21 * H- ) ] - 2 . 4H where : L = Length of spillway opening, Feet (FT. ) (6 ' minimum) H = Weir Head, Feet (FT. ) Q100 = Developed 100-year flow, Cubic feet/Second (C. F.S . ) 5 . All Biofiltration Swales will be sized using the Manning' s Equation for Open Channel Flow, Q = (1 .49/n) *A*R0.667*SO,5 where : Q = Design Flow Rate, Cubic Feet/Second (C. F. S . ) n = Mannings Roughness Coefficient _n = 0 . 20 @ Water Quality n = 0 . 035 @ Water Quantity A = Cross-sectional Area, Square Feet (S . F. ) R = Hydraulic Radius, Feet (FT. ) = A / wetted perimeter (P) S = Slope (FT. / FT. ) 7 IV. DESIGN CALCULATIONS PARAMERTERS CONT'D. : 6 . Design infiltration rate will be determined according to Section III-3 of the DOE Manual and is as follows : Q = fd * i * AS where : Q = Flow rate at which runoff is infiltrated fd = Design infiltration rate of soil i = Hydraulic gradient As = Surface area of infiltration additionally: fd = f/2 Factor of safety of 2 . 0 where : F = DOE infiltration rate i = (h + L) /L where : H = height of water colume over infiltration media L = Distance from infiltration media to water table or relative impervious layer. therefore : . Q =f/2 * (h+L) /L * AS 7 . Curve Numbers for the project are as follows : Given the Everett soils, the following Curve Numbers (CN) will be utilized: Second Growth Forest and/or Brush = 55 Grass in Fair Condition = 77 Pavement and Roofs = 98 (See Figure 4 in Appendix A) 8 B. BASIN A STORM WATER FACILITY DESIGN: 1. DEVELOPED CONDITIONS : At the developed condition, the runoff area for the retention/infiltration system consists of 6 . 55 acres and consists of the following: BASIN A DATA Future Land Use : Commercial Basin Size : 6 . 55 Acres Soil Type : Everett (Ed) ON-SITE CONDITION FUTURE Land Use Commercial Pervious Area 1 . 07 acres (1) CN Pervious Area 63 . 84 (2) Impervious Area 5 .48 acres CN Impervious Area 98 (3) (1) 0 . 64 acres Third Growth Forest and/or Brush @ CN = 55 0 . 43 acres Grass in Fair Condition CN = 77 (2) 0 . 64 * 55 + 0 .43 * 77 / 1 . 07 = CN = 63 . 84 (3) 5 .48 acres Pavement and Roofs CN = 98 (See Figure 4 in Appendix A) TIME OF CONCENTRATION PERVIOUS TIME: L1 = 77 ' , So= 334 . 0 - 331 . 0/77 = 3 . 900-. , ns= 0 . 40 , Pz= 3 . 65 LZ = 130 ' , So= 331 . 0 - 330 . 0/130 = 077%, ns= 0 . 40, PZ= 3 . 65 L3 = 97 ' , So= 330 . 0 - 326 . 0/97 = 4 . 120-. , ks= 11 L9 = 97 ' , So= 326 . 0 - 325 . 0/97 = 1 . 03%, ks= 27 L5 = 303 ' , So= 325 . 0 - 320 . 0/303 = 1 . 6501, ks= 27 IMPERVIOUS TIME: L1 = 175 ' , So= 333 . 0 - 330 . 0/175 = 1 . 71%, ns= 0 . 011, PZ= 3 . 65 LZ = 95 ' , So= 330 . 0 - 325 . 9/95 = 4 . 320-. , k5= 11 L3 = 90 ' , So= 325 . 9 - 325 . 0/90 = 1 . 00%, k5= 27 LQ = 303 ' , So= 325 . 0 - 320 . 0/303 = 1 . 6506, k5= 27 (See Figure 5 in Appendix A) 9 B. BASIN A STORM WATER FACILITY DESIGN• 2 . DESIGN INFILTRATION RATE: Determination of the design infiltration rate according to Section III-3 of the D.O.E. manual as follows : Q = f/2 * (h+L) /L * As where : f = 2 . 41 in. /hr. for loamy sand (See Figure 9 in Appendix A) h = variable depth of water L = 10 ' assumed per DOE Section III-3 example problem where no signs of ground water is encountered. AS = varying areas therefore: Q = (2 . 789E-5) * (h+L) /L * A; 3 . RETENTION/INFILTRATION POND DESIGN: The proposed retention/infiltration pond for Basin A has been modeled within Waterworks . The model, Storage List ID: pondA has the following geomerty: STAGE (FT) AREA (SF) 314 . 0 16011 .42 316 . 0 19558 . 08 318 . 0 23475 .45 320 . 0 27344 . 40 (See Waterworks Data for Stage Storage Table) 10 B. BASIN A STORM WATER FACILITY DESIGN• 3 . RETENTION/INFILTRATION POND DESIGN CONT'D: The Stage Discharge List ID : disA for the retention system was designed to provide needed storage volume while allowing for the infiltration flow rate at above mentioned design infiltration rate . Therefore, the Stage Discharge Table has the following geomerty: STAGE (FT) As AREA (SF) (h+10) /10 0 (CFS) 314 . 0 16011 .42 1 . 0 0 .45 316 . 0 19558 . 08 1 . 2 0 . 65 318 . 0 23475 .45 1 . 4 0 . 92 320 . 0 27344 .40 1 . 6 1 . 22 (See WaterWorks Data for Stage Discharge Table) Based upon the Stage Storage and Stagew Discharge Structures identified, the Level Pool Summary for the Developed 100-year, 24-hour storm event provides a Peak Stage of 318, 13 FT with a volume of 81, 998 . 5 CF. 4 . BIOFILTRATION SWALE DESIGN: The Biofiltration Swales were sized to provide water quality treatment at the 6-month storm event . Additionally, the 100-year peak runoff rate was routed through the Swales to ensure that flow velocity would not exceed a scouring velocity of 3 F. P.S . Due to the high flows associated with the developed site, two biofiltration swales channels were utilized. The following parameters were used to size each of the biofiltration swale : 11 B. BASIN A STORM WATER FACILITY DESIGN• 4 . BIOFILTRATION SWALE DESIGN CONT'D: Max. 6-month Flow 1 . 31 CFS (2 . 62 CFS total) Max. 100-yr Flow 4 . 21 CFS (8 . 41 CFS total) Side Slopes 3H: 1V Swale Length 200 Feet Longitudinal Slope 1 . 00 Percent Maximum Flow Depth 4 Inches Residence Time for Quality 4 Minutes Minimum Velocity for Capacity 3 FPS 6-month Manning ' s "n" 0 . 200 100-yr Manning' s "n" 0 . 035 Sizing Results (See Appendix B) : •- Swale Bottom Width 11 . 00 Feet 6-month Flow Depth 0 . 33 Feet (4 . 00 Inches) 6-month Flow Velocity 0 . 33 Feet per Second 6-month Flow Residence Time 200/0 . 33 = 606 Seconds or 10 . 1 Minutes 100-year Flow Depth 0 . 23 Feet (2 . 76 Inches) 100-year Flow Velocity 1 . 54 Feet Per Second (See Waterworks Data for Water Quality/Quantity Worksheet) 5 . EMERGENCY OVERFLOW SPILLWAY DESIGN: The emergency overflow spillway length was sized using the following data: L = [Qioo / (3 . 21 * H3/z) ) ] - 2 . 4H therefore : Q = 8 . 41 CFS = 100-year Peak Emergency Overflow H = 0 . 5 L = [8 .41/ (3 . 21 * (0 . 5) 3/I1 ) ] - 2 .4 (0 . 5) L = 6 . 21 Feet ( Use 6 . 25 Feet) 12 C. BASIN B STORM WATER FACILITY DESIGN• 1 . DEVELOPED CONDITIONS : At the developed condition, the runoff area for theretention/infiltration system consists of 5 . 38 acres and consists of the following : BASIN B DATA Future Land Use : Commercial Basin Size : 5 . 38 acres Soil Type : Everett (Ed) ON-SITE CONDITION FUTURE Land Use Commercial Pervious Area 0 . 78 acres (1) CN Pervious Area 62 . 05 (2) Impervious Area 4 . 60 acres CN Impervious Area 98 (3) (1) 0 . 53 acres Third Growth Forest and/or Brush @ CN = 55 0 . 25 acres Grass in Fair Condition CN = 77 (2) 0 . 53 * 55 + 0 .25 * 77 / 0 . 78 = CN = 62 . 05 (3) 4 . 60 acres Pavement and Roofs CN = 98 (See Figure 4 in Appendix A) TIME OF CONCENTRATION PERVIOUS TIME: L1 = 225 ' , So= 326 . 5 - 323 . 5/225 = 1 . 33%, ns= 0 . 40, P2= 3 . 65 L2 = 300 , So= 323 . 5 - 320 . 5/300 = 1 . 00%, ks= 27 L3 = 36 ' , So= 314 . 5 - 313 . 78/36 = 2 . 00%, kc= 21 Lq = 150 ' , So= 318 . 25 - 316 . 75/150 = 1 . 00%, kc= 17 L5 = 95 ' , So= 316 . 0 - 315 . 25/75 = 1 . 000-. So= 315 . 25 - 314 . 5/20 = 3 . 75% So= 1 . 0096*75 + 3 . 75%*20/95 = 1 . 580-. , ks= 21 13 C. BASIN B STORM WATER FACILITY DESIGN: 1 . DEVELOPED CONDITIONS CONT'D: IMPERVIOUS TIME: L, = 300 ' , So= 325 . 7 - 325 . 0/45 = 1 . 56% + S,,= 325 . 0 - 322 . 45/255 = 1 . 001, _ So= 1 . 08% n5= 0 . 40 , P,= 3 . 65 L, = 145 ' , So= 322 .45 - 321 . 00/145= 1 . 00%, k;= 27 L; = 3361 , So= 317 .5 - 314 . 5/300 = 1 . 00% + So= 314 . 5 - 313 . 78/36 = 2 . 00% = S�= 1 . 11%, k5= 21 (See Figure 5 in Appendix A) 2 . DESIGN INFILTRATION RATE: Determination of the design infiltration rate according to Section III-3 of the D.O. E. manual as follows : Q = f/2 * (h+L) /L * AS where : f = 2 .41 in. /hr. for loamy sand (See Figure 9 in Appendix A) h = variable depth of water L = 10 ' assumed per DOE Section III-3 example problem where no signs of ground water is encountered. AS = varying areas therefore: Q = (2 . 789E-5) * (h+L) /L * As 14 C. BASIN B STORM WATER FACILITY DESIGN: 3 . RETENTION/INFILTRATION POND DESIGN: The proposed retention/infiltration pond for Basin B has been modeled within Waterworks . The model, Storage List ID: pondB has the following geomerty: STAGE (FT) AREA (SF) 314 . 0 10886 . 04 316 . 0 13872 . 91 318 . 0 17164 . 04 320 . 0 20494 . 38 (See Waterworks Data for Stage Storage Table) The Stage Discharge List ID: disB for the retention system was designed to provide needed storage volume while allowing for the infiltration flow rate at above mentioned design infiltration rate. Therefore, the Stage Discharge Table has the following geomerty: STAGE (FT) As AREA (SF) (h+10) /10 CFS 314 . 0 10886 . 04 1 . 0 0 .30 316 . 0 13872 . 91 1 . 2 0 .46 318 . 0 17164 . 04 1 .4 0 . 67 320 . 0 20494 . 38 1 . 6 0 . 91 (See WaterWorks Data for Stage Discharge Table) Based upon the Stage Storage and Stage Discharge Structures identified, the Level Pool Summary for the j Developed 100-year, 24-hour storm event provides a Peak Stage of 318, 77 FT with a volume of 70, 222 CF. t 15 C. BASIN B STORM WATER FACILITY DESIGN: 6 . OVERFLOW INFILTRATION TRENCH DESIGN CONT'D: The available volume for the trench listed above is dependent upon the percent void At each stage identified. The rock within the trench is assumed at 30 percent void. The cross-sectional area of the 4 foot diameter pipe at a given stage is determined as follows : STAGE (FT) d D A/D2 AREA*2 (SF) 313 . 0 1/4 0 . 1535 4 . 92 314 . 0 1/2 0 . 3927 12 . 56 -- 315 . 0 3/4 0 . 6318 20 . 22 316 . 0 Full 0 . 7854 25 . 00 Based upon the cross-sectional area of the trench (300 void) less the cross-sectional area of the pipe (1000 void) for a given stage, the CF/FT volume is as follows : STAGE X-SECTIONAL AREA o VOID VOLUME FT SF (CF/FT) 312 . 0 13 x 1 13 . 00@0 . 30 3 . 90 313 . 0 13 x 2 4 . 92@1 . 00 11 . 24 21 . 08@0 . 30 314 . 0 13 x 3 12 . 56@1 . 00 20 .49 26 . 44@0 . 30 315 . 0 13 x 4 20 . 22@1 . 00 29 . 75 31 . 78@0 . 30 316 . 0 13 x 5 25 . 00@1 . 00 37 . 00 40 . 00@0 . 30 317 . 0 13 x 6 25 . 00@1 . 00 40 . 90 53 . 00@0 . 30 18 C. BASIN B STORM WATER FACILITY DESIGN: 6 . OVERFLOW INFILTRATION TRENCH DESIGN CONT'D: Therefore, the Stage Storage Table associated with a 200 FT. long trench with the cross-sectional properties listed above is as follows : STAGE (FT) VOLUME (CF) 311 . 0 200 x 0 . 00 0 . 0 312 . 0 200 X 3 . 90 780 . 0 313 . 0 200 X 11 . 24 2248 . 0 314 . 0 200 x 20 .49 4098 . 0 315 . 0 200 x 29 . 75 5950 .-0 316 . 0 200 X 37 . 00 7400 . 0 317 . 0 200 X 40 . 90 8180 . 0 The Stage Discharge table for the retention system will be designed to provide needed storage volume while allowing for infiltration at the following rates : Q = f/2 * (h+L) /L * AS where: f = 2 .41 in. /hr. = 5 . 58E-5 for loamy sand (See Figure 9 in Appendix A) h = variable depth of water L = 10 ' assumed per DOE Section III-3 example problem where no signs of ground water is encountered. AS = 2600 SF. ( based on a 13 ' x 200 ' trench bottom) therefore: Q = (2 . 789E-5) * (h+L) /L * 2600 Q = 0 . 073 * (h+L) /L 19 C. BASIN B STORM WATER FACILITY DESIGN: 6 . OVERFLOW INFILTRATION TRENCH DESIGN CONT'D: The Stage Discharge Table is as follows : STAGE (H+L) /L 0 (CFS) 311 . 0 1 . 0 0 . 07 312 . 0 1 . 1 0 . 08 313 . 0 1 . 2 0 . 09 314 . 0 1 . 3 0 . 09 315 . 0 1 .4 0 . 10 316 . 0 1 . 5 0 . 11 317 . 0 1 . 6 0 . 12 (See Waterworks Data in Appendix A) Based upon the Stage Storage and Stage Discharge Structures identified, the developed 100-year, 24- hour Storm Event provides a Peak Volume of 8180 . 0 CF of additional storage volume. 20 APPENDIX A - FIGURES 0 o � OLD 8Ej p OLD BELFAIR HWY. z o o Ro RpII,R O~ O MASON CO. KTTSAP CO. BREMERTON w '. •• Y� �:yii• t • •• =`.inp �,�' `�r,.,� ,'�:T�: .,�+•: :n\!�.�jYq+!+;Ft• ��: i.!�� .�� ���• { ♦ r�• t•�t/~.a ia+�i�a••:_ ,{? j 1!t`1 �Y~.:. ,a..,,�•..�i.fi/w� �`"�.`�4,viy."r��.a �..V- _ 7A? 11 a /!-a •.h'�''�� VLE •' ��•�„��r.a.• � .'"`w' ,,s,• '� .iA ' �Q7i� f`r i.•. . �� ice' �' '�'�r: -''•7Z`"•�jijYy�e ..i.• '•7t��� _t ..r w���'lr�a �•- 1yi�'+� ����'�": a �• •Y!�i r it ar��•::j�� ti ti 1,�I:•ry�1�� ��. �yl `r � x^�i],+e�b�. t. •2 yI'!-�.ar�{J��•w f ••�s���ytill , r� {'. ~'..�`!1.�� ••�+� 1� �Izr ,SY• >a. ...a. • ��•: •'f`�v^ •4�5. YL:.:ss F -.t"; •.;,-� L �- A v •,. •. S i •.`,. i•` :! �7w:• ` •t'^ may. ..� •��ya a ti .f ••.a.r ..,I• .�` r•� •'�;�.�J!ti`�:..�.•.J�S.r�•4- w•y•w%fit _ a '•� 'ZG'u"• •r ♦:e�9�.;-,,.,�'�}-�� t'.+� ':. � yi{j.' - ?`w y�•'�s�t••�� ����irb�� lY a s • }s• k4���Q�./,ra•L��r"":t'.?:iiZ�.,.•,a 1tt v � 's'{�:•'�r��„L.`:},y.�► ,�[!•�'t. :}'•"�rll�� °� �?!�'.`_�j'+�,�, �- 4'iC i�+r� w M ltiM //: i�dss.`�,,��; �•, `zj�,iy!/►'•�..� 7•w/iG~1 1''«:�1�•�it a;. ��. �;Ti`��_ it=•'..Iii►r.'C4tl...,a1�i4»-•}.1+�..� VZq: N• - �^•,`74 M••+ Wv'f.y.'•C':"Y,•.k` .1•�e :�i �lir 40, -s T 'a s .� •� l•a '. 1� Yw�� '{�A►` �i•t�;)�?,-� at♦ - • a���1}f=�� � ' s .�l��yyyy tt ram'"••r. Li} �r� • �'F° :ra'ra. :'€�3R�� 1 + f.M J-•r.:t►f2•. dNy�:? .i.,� s; .l � :d: •yS,r �. rt•• r..,"r- . '��„ 4dY y��sp�,f 4 ,10 1►'�;. •50m. ,• PU •y�� ! c.,, •/�..}.t 3!y � .y t .Z",� �•.1A�i. .}�t.-....."�a�(�hi�i4��g'•yY''��;t t �yRA��2,•i�a;�!•�� .%lG:.:.r+a t 7i'. - °'ti' t`?w !'•i'1'"' `.'� s T <r if y�F'► '``'!1+:'i.��!'•i►.a 7t� t ryw a`- 'ji. 'v-t�/ ;�t��yyf• i T� ♦ a 'VwJ } {�: �f'•.. �...► G TjY.�•I r! aiti. �' :.� :Ii1 r' a:�Rt a�-Y.f a.} . bi'...'. h'�. ( 1 `�1 �s� alL ! 1M-F''•t� ?s L�r F ` 1 ,t 3� ♦ v iyi" yw �Saw'� RNA-`ti - =as.{ . * � .ti: rsv ,lx�'�¢.�.. .?, •tY.i'•. .r'i{t•�,xV2 arc >yik",�{�• •+' a�23"'�,a!r ..T• ♦ `+:. /•. t?'� '!l "i1.� \ ZM ! "i�r� ' ,;. �:� �5 ; _ , .�•.•.• .6^ RO r rr#� 1i►� *� `azt. � s •�•af,, 3e i � fir. •' Ns� 1 �iip tZ.t JL •��'3; �„K "g.`••ic. v�•.,� �'n'�tA + • •�`����.�`..�4.��,.• �`t����t�!.y�t•�.�•���4t r'�=;i-^=t�;��'�`��.�.��t?. ;�.••)�i•o-r,. !�-„� - l A'1 I -f• �' ` S y1'i�~. r t4i��o-•� 11I a►` R- fl s�~r ,��s a T►•i��I• S . .,� c,� c_R { �'�{+�+� ..';-fir..• y r ^•r 1:•i.',�•;"'1►!~�r'ari;'i t y'� f- •s.•• .+r. �'` �Sy '•„ ' :..Y S 'S �'_ij. .J• s,./} f9?~%+' `!^rW;..`• ii'�. •►.�1�.V'S`}.' ;.�Yt�► }i,j.�'�'t "',�.� ?F J•"`U'°`��t '� .� st ,w .�y :34+,5:,�,?kr ,r- ���.-• �:, �� �� II ��:� •�e.� e.�•. tit= �{�- i•;��j/ �: �'•��t�.`•*v�`.��!' ��tiy.��•.�{1r� A, .•;� -tl "tL- s-,r.,j' n.. Y ;t tifi �'!�.� e: a t .•� '!S� �i1iT'�Y`�`vY�y� "*•�• .�,•.�;� r�•wy�. t'• ' q,r�'A: 'T.�;t:-i i iY ♦ i •c.. w•,. e4'�'1a+���t�K���!�'��'`�iMiP�j�`:�«i"��� '� �Y #- t rAI vi m , •• '"�SS:•y<<t�'r�•r� ',tl Y r.-:-. ma's ?. Y/y� � �►�r�i .{,_j t.�a.��:•'i'•� i7 M,~i •* • Sr ri o r •4:r �. v • i. f - .T• �'i. .-Ng -. r. �..-,�:ntS+.*fwA•. r�• •}i;.�.fL. iP r�� •f+r , �l.r�'2 .!a't^ ) s� �`+} - ', v �.��� IiI 1� .7..:b: �'..ati i �►--t rTa_�-. ya.�1'� t<' s.r a..-t t�✓�a �i i" may.. 't i' I,1• a.�j�r� a s►i�'�'• �:w+r •• i'f• ' 1'iy ,:"'... pia! , ♦ ;. i ,�:•. r F•7� �� ,la"", �`=Nti� �..���• ��';'.• s.ti. .7: �`* -• ict„� tiy. .►�•if« i��4.s,�-s:ti t �,t. Y: ?r�l:.. '4 �vf r'♦. + �• �� t t�s •�. ., t�") lJti;,'• f.�,.}7i'.'. ..Yjt�`b4Y^lr-v.:` "s .-.3 ah��a�c 1 N (71 r o uzz❑ ❑ ° A ❑ uummma ❑ A ¢ m ❑ auuzzzzzuzzAzz zu ❑ mcuumA ° ❑ m ❑ z ❑ ❑ muuu ❑ mz ❑ mzA L 20 4 z 9 Ix T Q � CQ A C z - 5 0 H W O a a w � x 8 a QQ E' E E' 'E b ay ° a 3 3 u u ? y u ` > C 0 ° g ° S o A S_' o Gv U �J A C� a ' > e u L Q b o 0 0 ° u u > o „ m 4 9 o f o' o E t r c ° u °c o 0 0?G OC oG iZ 0. n n w rn Vn Vn En (n rn Ln Ln v) n in v) vd) Vn v) Vn rn Vn U ° e ❑ A A ❑ A ❑ ❑ � ❑ ❑ umuummmmummu0umA ❑ umuzzummm ¢ mumuuuuzzumzzzummu ❑ zmzpm � maza GN i z E � b i T H Q � 0 C H n Lo uuu v u E E u > u u u • a a O s u � iuuuua� a� a� a� � a� � � aa � zzzz STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-1.3 SCS Western Washington Runoff Curve Numbers (Published by SCS in 1982) Runoff curve numbers for selected agricultural, suburban and urban land use for T lA rainfall distribution, 24-hour storm duration. LAND USE DESCRIPTION CURVE NUMBERS BY HYDROLOGIC SOIL GROUP F B C D Cultivated land(1) : winter condition 86 91 94 95 Mountain open areas: low growing brush & grasslands 74 82 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land: undisturbed 42 64 76 81 Wood or forest land: young second growth or brush 55 72 81 86 Orchard: with cover crop 81 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping. 1. Good condition: grass cover on z75% of the 68 80 86 90 area Fair condition: grass cover on 50-7S% of 77 85 90 92 the area Gravel roads & parking lots: 76 85 89 91 Dirt roads & parking lots: 72 82 87 89 Impervious surfaces, pavement, roofs etc. 98 98 98 98 Open water bodies: lakes, wetlands, ponds etc. 1100 100 100 100 Single family residential(2) : Dwelling Unit/Gross Acre %Impervious(3) Separate curve number 1.0 DU/GA 15 shall be selected for 1.5 DU/GA 20 pervious & impervious 2.0 DU/GA 25 portions of the site 2.5 DU/GA 30 or basin 3.0 DU/GA 34 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 PUD's, condos, apartments, %impervious commercial businesses & must be industrial areas computed (1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Sec. 4, Hydrology, Chapter 9, August 1972. (2) Assumes roof and driveway runoff is directed into street/storm system. (3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers. III-1-12 FEBRUARY, 1992 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN Table III-1.4 "n" AND "k" Values Used in Time Calculations for Hydrographs "n'" Sheet Flow Equation Manning's Values (for the initial 300 ft. of travel) na Smooth surfaces (concrete, asphalt, gravel, or bare hand packed soil) 0.011 Fallow fields or loose soil surface (no residue) 0.05 Cultivated soil with residue cover (s_< 0.20 ft/ft) 0.06 Cultivated soil with residue cover (s> 0.20 ft/ft) 0.17 Short prairie grass and lawns 0.15 Dense grasses 0.24 Bermuda grass 0.41 Range (natural) 0. 13 Woods or forest with light underbrush 0.40 Woods or forest with dense underbrush 0.80 *Manning values for sheet flow only, from Overton and Meadows 1976 (See TR-55, 1986) "k" Values Used in Travel Time/Time of Concentration Calculations Shallow Concentrated Flow (After the initial 300 ft. of sheet flow, R = 0.1) kg 1. Forest with heavy ground litter and meadows (n = 0. 10) 3 2. Brushy ground with some trees (n = 0.060) 5 3. Fallow or minimum tillage cultivation (n = 0.040) 8 4. High grass (n = 0.035) 9 5. Short grass, pasture and lawns (n = 0.030) 11 6. Nearly bare ground (n = 0.25) 13 7. Paved and gravel areas (n = 0.012) 27 Channel Flow (intermittent) (At the beginning of visible channels R = 0.2) kc 1. Forested swale with heavy ground litter (n = 0.10) 5 2. Forested drainage course/ravine with defined channel bed (n = 0.050) 10 3. Rock-lined waterway (n = 0.035) 15 4. Grassed waterway (n = 0.030) 17 5. Earth-lined waterway (n = 0.025) 20 6. CMP pipe (n = 0.024) 21 7. Concrete pipe (0.012) 42 8. Other waterways and pipe 0.508/n Channel Flow (Continuous stream, R = 0.4) k� 9. Meandering stream with some pools (n = 0.040) 20 10. Rock-lined stream (n = 0.035) 23 11. Grass-lined stream (n = 0.030) 27 12. Other streams, man-made channels and pipe 0.807/n** III-1-16 FEBRUARY, 1992 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN 124 123 122 121 49 i _ 25 25 a w w ww w XIMIs 39 25 2e to BE w 2f OLGA I .25 C � n ; I)�\ \ FRIDAY HARBOR PORT STA LEY (\ _40 `. MT 30 ya n I ;E 1 Rr I y/c u20 10 35 302510 I0� 1. �? 3 Allst . 48, f R ` /� E R E T T ? 40 f6 rs'. - f I 1 15 21 25 c 429 50 ' ss 2b s15c s v 30 5 's 45I _ / S AT ���j ,k • vU C 40� a J ' 35' 55 20 s — 3 \ /5 40 35 COMA — 2 47 3 3 10 E AS RDE N r 3o m 2s 2s 35 f 13 40 'CENT w O 55. \ 10 YAKI 7• k 20 45' s 40 35 \ ADA 46, 3 2 E (� 'f ss S0 WASHINGTON '0 3 25 e K 10 0 10 20 30 40 PPL EN E ----� MILES 20 a 15 2 Figure 25 ' 25'--` NOAA ATLAS 2, Volume IX ISOPLUVIALS F 2-YR 24-HR PRECIPITATI N IN Prepared by U.S.Department of C morce TENTHS OF A INCH National Oceanic and Atmospheric ministration National Weather Service,Office of Hydrology Prepared for U.S.Department of A riculture, Sol[Conservation Service,Engineer g Division 124 123 122 121 • III-1-44 FEBRUARY, 1992 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN 124 123 122 121 49 _ I 4 45 _ 80 r s EL T � 0 , �t c 45 la'" A, cJs 40 o. � � GA � � \ 1 ( 4 - \ 55 � \ F IEL MAR C' •FORT SlArj-' � Q+ 7S 8085 \ 35 30/f \ ` r 70 5 0 t f I / � 5 10 1 6 0 75 I 1 2 I ,OAS 3 3 55 4 8 i5 10) -OAS Aift� 75 3 _ 251 ° 8U f L�, 85. 1 5 45 ' ° 0 ; 90� 100, E w s s 100. s so , 90.. i 1 40 AT 5 a e 4 s 1 841 (40 0� 2 60 S s 4 7 55, 5 ' :. 0 6 4 3 ! � 65 3 \ ABE E N 5 �i0 i — 5 2 _ a s 70 4 r 1 R L 7° w 'S /( 75 - 2 I 60 7S 22 ••YAK 6d 55 } 45 to pro s 55+• lam' ° � —�,f �s s s 10 65 7d, T p 0 65 60 55 10 ' AD M -30 �25. 46 w 1 I C� WASHINGTON 4° i ° �° 40 ' — tCKLI O F'• ' `GP.'Cp E N E 10 0 10 20 30 40 � •80 , '—� MILES 40 to iFigure 30 I NOAA ATLAS 2,Volume IX ISOPLUVIALS F 100-YR 24-HR PRECIPIT !TION 45 5055 60 65 Prepared by U.S.Department of C merce ional+ IN TENTHS OF N INCH q National Weatheeanic rsery a office of ministration I Y gY Prepared for U.S.Department of Apiculture, � Soil Conservation Service,Engineer g Division 124 123 122 12i ' III-1-46 FEBRUARY, 1992 R c-A . �-asan o _ a M+Opl1 1.1E1p11 / Y a MM]CRI / w . E� s a ftli" a oafs rat FNE OM R10� RkW ROW PO"O ti RErE"r oR Po"o JN rORBAY CELL crfmjm a1a MommlloR (m oEuan 1p a w I I'm sm arrz a+sA RETErAgN PO"O i SECO"O CELL _ •7 W MS■-17 A1AR aIr EL EOOE Or►awww - 7 rfK■.a,. TO RE- 1 STA 0-OOI R EOOE 6 S'fJ1r6 -71fA MK1Ol1 Ina Inr+CK) •WAM A -71.A - E.O.AEO mom - IEEE auas) MCC Of.c rwo[n tr `Y. • /KENK OMTE m ouftr si.woo a Scale: 1"=IW . �i C�• SA V�LOP� r avo rr,ct-& t�/1 EW EDGE OF PAVEMENT N —EDGE OF PAVEMENT I N n o f, 25. .. o-v , 1%N 'N J N � zz• p RETENTION m POND 'B' SECOND CELL 84' 1e' - 1 72' I - RETENTION POND 'B' FOREBAY CELL 104 M 107' \ is \ '•ASS \ N-12 Ct _ N SWALE \ I MH /1 TYPE II\ 48 m \ W/ STD. GRATE \ \E=319.0 \ LF 24' A05 N-12 \ �' • uw I') TYPr 11 4R"m. r t1i� • ■ C ' \ \ ��nenn" w w w v �3 w to tT y r-tD O H Infiltration Cation Exchange Effective N y H Texture Rate Capacity Water Capacity Hydrologic I y� Class Hydrologic (milliequivalents/ (inches per Soil Group U (inchmfhr.) 100 grams) inch) Coarse Sands or Cobbles 20.00 <5.0 --- A to 0 O r Sand 8.27 <5.0 0.35 A ~' ° z N Loamy Sand 2.41 5.0 0.31 A 0 y N N Sandy Loam 1.02 >5.0 0.25 B � w rr C: Loam 0.52 >5.0 0.19 B F- y m t' Silt Loam 0.27 >5.0 0.17 C n ny r O Sandy Clay Loam 0.17 >5.0 0.14 C w �U to y m Clay Loam 0.09 >5.0 0.14 D M r• Silty Clay Loam 0.06 >5.0 0.11 D Q G� Sandy Clay 0.05 >5.0 0.09 D �3 Silty Clay 0.04 >5.0 0.09 D 0 O r• C: Clay 0.02 >5.0 0.08 D ~ Uz y Source(except for cation exchange capacity): Rawls, Brakensiek,and Saxton, 1982(16) k r* to � G N n z Cation exchange capacity values arc estimated from Buckman and Brady, 1969,(23) (D �C N l H A ul m P4 O 3 P4 W E4 z H co �i W 12/1/99 11 : 6 : 2 am NL Olson & Assoc. Inc. page 1 North Mason Fiber Company Final Storm Report Developed Conditions Basin A BASIN SUMMARY BASIN ID: ADEV-100 NAME: Basin A Dev. 100-year, 24-hr SBUH METHODOLOGY TOTAL AREA. . . . . . . : 6 .55 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 7 .00 inches AREA. . : 1 . 07 Acres 5 .48 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 63 . 84 98 .00 TC. . . . . 51 .59 min 5 . 00 min ABSTRACTION COEFF: 0 .20 TcReach - - Sheet L: 77 . 00 ns : 0 .4000 p2yr: 3 . 65 s : 0 .0390 TcReach - Sheet L: 130 .00 ns :0 .4000 p2yr: 3 .65 s : 0 . 0077 TcReach - Shallow L: 97 .00 ks:11 . 00 s :0 .0412 TcReach - Shallow L: 97 . 00 ks :27 . 00 s :0 . 0103 TcReach - Shallow L: 303 . 00 ks :27 . 00 s : 0 . 0165 impTcReach - Sheet L: 175 .00 ns : 0 . 0110 p2yr: 3 . 65 s : 0 . 0171 impTcReach - Shallow L: 95 .00 ks :11 . 00 s : 0 . 0432 impTcReach - Shallow L: 90 . 00 ks :27 . 00 s : 0 . 0100 impTcReach - Shallow L: 303 .00 ks:27 . 00 s : 0 . 0165 PEAK RATE: 8 .41 cfs VOL: 3 .35 Ac-ft TIME: 480 min BASIN ID: ADEV-6m NAME: Basin A Dev. 6-month, 24-hr SBUH METHODOLOGY TOTAL AREA. . . . . . . : 6 .55 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 2 .34 inches AREA. . : 1 . 07 Acres 5 .48 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 63 .84 98 .00 TC. . . . . 51 .59 min 5 . 00 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 77 . 00 ns: 0 .4000 p2yr: 3 . 65 s : 0 . 0390 TcReach - Sheet L: 130 . 00 ns :0 .4000 p2yr: 3 . 65 s : 0 .0077 TcReach - Shallow L: 97 . 00 ks:11 . 00 s : 0 . 0412 TcReach - Shallow L: 97 . 00 ks:27 . 00 s :0 .0103 TcReach - Shallow L: 303 . 00 ks:27 . 00 s : 0 . 0165 impTcReach - Sheet L: 175 . 00 ns : 0 . 0110 p2yr: 3 . 65 s : 0 . 0171 impTcReach - Shallow L: 95 . 00 ks : 11 . 00 s : 0 . 0432 impTcReach - Shallow L: 90 .00 ks :27 . 00 s :0 . 0100 impTcReach - Shallow L: 303 . 00 ks :27 . 00 s : 0 . 0165 PEAK RATE: 2 . 62 cfs VOL: 0 . 98 Ac-ft TIME: 480 min 12/1/99 11 :6 :2 am NL Olson & Assoc. Inc. page 2 North Mason Fiber Company Final Storm Report Developed Conditions Basin A --------------------------------------------------------------------- --------------------------------------------------------------------- HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf\AcFt Acres --------------------------------------------- --------------------------------------------- 1 8 .408 480 146086 cf 6 .55 2 2 . 623 480 42831 cf 6 . 55 3 0 . 940 1350 130437 cf 6 .55 4 0 .517 790 42831 cf 6 .55 6 6 . 845 480 120839 cf 5 .38 7 2 . 147 480 35750 cf 5 .38 8 0 . 762 1360 103345 cf 5 .38 9 0 .376 800 35750 cf 5 .38 12/1/99 11 : 6 :2 am NL Olson & Assoc. Inc. page 3 North Mason Fiber Company Final Storm Report Developed Conditions Basin A STAGE STORAGE TABLE CUSTOM STORAGE ID No. pondA Description: Basin A Retention Pond STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- 314.00 0.0000 0.0000 315.60 28456 0.6533 317.20 61390 1.4093 318.80 98931 2.2711 314.10 1778 0.0408 315.70 30234 0.6941 317.30 63541 1.4587 318.90 101472 2.3295 314.20 3557 0.0817 315.80 32013 0.7349 317.40 65693 1.5081 319.00 104013 2.3878 314.30 5335 0.1225 315.90 33791 0.7757 317.50 67845 1.5575 319.10 106554 2.4461 314.40 7114 0.1633 316.00 35570 0.8166 317.60 69996 1.6069 319.20 109095 2.5045 314.50 8892 0.2041 316.10 37721 0.8660 317.70 72148 1.6563 319.30 111636 2.5628 314.60 10671 0.2450 316.20 39873 0.9154 317.80 74300 1.7057 319.40 114177 2.6211 314.70 12449 0.2858 316.30 42025 0.9648 317.90 76451 1.7551 319.50 116718 2.6795 314.80 14228 0.3266 316.40 44176 1.0141 318.00 78603 1.8045 319.60 119259 2.7378 314.90 16006 0.3675 316.50 46328 1.0635 318.10 81144 1.8628 319.70 121800 2.7961 315.00 17785 0.4083 316.60 48480 1.1129 318.20 83685 1.9211 319.80 124341 2.8545 315.10 19563 0.4491 316.70 50631 1.1623 318.30 86226 1.9795 319.90 126882 2.9128 315.20 21342 0.4899 316.80 52783 1.2117 318.40 88767 2.0378 320.00 129423 2.9711 315.30 23120 0.5308 316.90 54935 1.2611 318.50 91308 2.0961 315.40 24899 0.5716 317.00 57086 1.3105 318.60 93849 2.1545 315.50 26677 0.6124 317.10 59238 1.3599 318.70 96390 2.2128 12/1/99 11:6 :2 am NL Olson & Assoc. Inc. page 4 North Mason Fiber Company Final Storm Report Developed Conditions Basin A ---------- STAGE DISCHARGE TABLE DISCHARGE LIST ID No. disA Description: Infiltration Rate Discharge STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- ------- - - ------------------------------------------------------------------------------------- 314.00 0.4500 315.60 0.6100 317.20 0.8120 318.80 1.0400 314.10 0.4600 315.70 0.6200 317.30 0.8255 318.90 1.0550 314.20 0.4700 315.80 0.6300 317.40 0.8390 319.00 1.0700 314.30 0.4800 315.90 0.6400 317.50 0.8525 319.10- 1.0850 314.40 0.4900 316.00 0.6500 317.60 0.8660 319.20 1.1000 314.50 0.5000 316.10 0.6635 317.70 0.8795 319.30 1.1'150 314.60 0.5100 316.20 0.6770 317.80 0.8930 319.40 1.1300 314.70 0.5200 316.30 0.6905 317.90 0.9065 319.50 1.1450 314.80 0.5300 316.40 0.7040 318.00 0.9200 319.60 1.1600 314.90 0.5400 316.50 0.7175 318.10 0.9350 319.70 1.1750 315.00 0.5500 316.60 0.7310 318.20 0.9500 319.80 1.1900 315.10 0.5600 316.70 0.7445 318.30 0.9650 319.90 1.2050 315.20 0.5700 316.80 0.7580 318.40 0.9800 320.00 1.2200 315.30 0.5800 316.90 0.7715 318.50 0.9950 315.40 0.5900 317.00 0.7850 318.60 1.0100 315.50 0.6000 317.10 0.7985 318.70 1.0250 12/1/99 11 :6:4 am NL Olson & Assoc . Inc. page 5 North Mason Fiber Company Final Storm Report Developed Conditions Basin A --------------------------- LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAR-> OUTFLOW STORAGE <--------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id (cfs) VOL (cf) 100-year Storm Event ......... 0.00 8.41 pondA disA 318.13 3 0.94 81998.51 cf 6-month Storm Event .......... 0.00 2.62 pondA disA 314.67 4 0.52 11843.10 cf Trapezoidal Channel Analysis & Design Open Channel - Uniform flow Worksheet Name : N . Mason Fiber #5089 Comment : 6-month Biofiltration Swale A Design Solve For Depth Given Input Data : Bottom Width. . . . . 11 . 00 ft Left Side Slope . . 3 . 00 : 1 (H:V) Right Side Slope . 3 . 00 : 1 (H :V) Manning' s n. . . . . . 0 . 200 Channel Slope . . . . 0 . 0100 ft/ft Discharge . . . . . . . . 1 . 31 cfs Computed Results : Depth. . . . . . . . . . . . 0 . 33 ft Velocity . . . . . . . . . 0 . 33 fps Flow Area . . . . . . . . 3 . 93 sf Flow Top Width. . . 12 . 97 ft Wetted Perimeter . 13 . 07 ft Critical Depth. . . 0 . 08 ft Critical Slope . . . 1 . 3929 ft/ft Froude Number . . . . 0 . 11 ( flow is Subcritical ) Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods , Inc . * 37 Brookside Rd * Waterbury, Ct 06708 Circular Channel Analysis & Design Solved with Manning ' s Equation Open Channel - Uniform flow Worksheet Name : N . Mason Fiber #5089 Comment : Basin A Pipe Capacity Verification 24" Dia . Solve For Actual Depth Given Input Data : Diameter . . . . . . . . . . 2 . 00 ft Slope . . . . . . . . . . . . . 0 . 0100 ft/ft Manning ' s n. . . . . . . 0 . 015 Discharge . . . . . . . . . 8 . 41 cfs Computed Results : Depth. . . . . . . . . . . . . 0 . 92 ft Velocity. . . . . . . . . . 6 . 00 fps Flow Area . . . . . . . . . 1 . 40 sf Critical Depth. . . . 1 . 03 ft Critical Slope . . . . 0 . 0066 ft/ft Percent Full . ... . . . 45 . 76 % Full Capacity . . . . . 19 . 61 cfs QMAX @. 94D . . . . . . . . 21 . 09 cfs Froude Number . . . . . 1 . 26 ( flow is Supercritical ) Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods , Inc . * 37 Brookside Rd * Waterbury, Ct 06708 BASIN B - WATERWORKS DATA 12/1/99 10 : 57 :48 am NL Olson & Assoc. Inc . page 1 North Mason Fiber Company Final Storm Report Developed Conditions - Basin B --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID: BDP-100 NAME: Basin B Dev. 100-year Pond SBUH METHODOLOGY TOTAL AREA. . . . . . . : 5 .38 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPElA PERV IMP PRECIPITATION. . . . : 7 .00 inches AREA. . : 0 . 78 Acres 4 . 60 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 62 . 05 98 . 00 TC. . . . : 49 .41 min 8 . 99 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 225 . 00 ns : 0 .4000 p2yr: 3 . 65 s : 0 . 0133 TcReach - Shallow L: 300 . 00 ks :27 . 00 s : 0 . 0100 TcReach - Channel L: 36 . 00 kc : 21 . 00 s : 0 . 0200 TcReach - Channel L: 150 . 00 kc : 17 . 00 s : 0 . 0100 TcReach - Channel L: 95 . 00 kc : 21 . 00 s : 0 . 0158 impTcReach - Sheet L: 300 . 00 ns : 0 . 0110 p2yr: 3 . 65 s : 0 . 0108 impTcReach - Shallow L: 145 . 00 ks :27 . 00 s : 0 . 0100 impTcReach - Channel L: 336 . 00 kc :21 . 00 s : 0 . 0111 impTcReach - Channel L: 150 . 00 kc : 17 . 00 s : 0 . 0100 impTcReach - Channel L: 95 . 00 kc : 21 . 00 s : 0 . 0158 PEAK RATE: 6 . 85 cfs VOL: 2 . 77 Ac-ft TIME : 480 min BASIN ID: BDP-6m NAME: Basin B Dev. 6-month Pond SBUH METHODOLOGY TOTAL AREA. . . . . . . : 5 .38 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 2 .34 inches AREA. . : 0 . 78 Acres 4 . 60 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 62 . 05 98 . 00 TC. . . . . 49 .41 min 8 . 99 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 225 . 00 ns : 0 .4000 p2yr: 3 . 65 s : 0 . 0133 TcReach - Shallow L: 300 . 00 ks :27 . 00 s : 0 . 0100 TcReach - Channel L: 36 . 00 kc :21 . 00 s : 0 . 0200 TcReach - Channel L: 150 . 00 kc : 17 . 00 s : 0 . 0100 TcReach - Channel L: 95 . 00 kc :21 . 00 s : 0 . 0158 impTcReach - Sheet L: 300 . 00 ns : 0 . 0110 p2yr: 3 . 65 s : 0 . 0108 impTcReach - Shallow L: 145 . 00 ks : 27 . 00 s : 0 . 0100 impTcReach - Channel L: 336 .00 kc :21 . 00 s : 0 . 0111 impTcReach - Channel L: 150 . 00 kc : 17 . 00 s : 0 . 0100 impTcReach - Channel L: 95 . 00 kc : 21 . 00 s : 0 . 0158 PEAK RATE: 2 . 15 cfs VOL: 0 . 82 Ac-ft TIME : 480 min 12/1/99 10 :57 :48 am NL Olson & Assoc . Inc . page 2 North Mason Fiber Company Final Storm Report Developed Conditions - Basin B --------------------------------------------------------------------- --------------------------------------------------------------------- HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf\AcFt Acres --------------------------------------------- --------------------------------------------- 1 8 .408 480 146086 cf 6 . 55 2 2 . 623 480 42831 cf 6 . 55 3 0 . 940 1350 130437 cf 6 . 55 4 0 .517 790 42831 cf 6 . 55 6 6 . 845 480 120839 cf 5 .38 --- 7 2 . 147 480 35750 cf 5 . 38 8 0 . 762 1360 103345 cf 5 . 38 9 0 .376 800 35750 cf 5 . 38 12/1/99 10 : 57 :48 am NL Olson & Assoc . Inc . page 3 North Mason Fiber Company Final Storm Report Developed Conditions - Basin B ------------ STAGE STORAGE TABLE CUSTOM STORAGE ID No. pondB Description: Basin B Retention Pond STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- --- ----------------------------------- 314.00 0.0000 0.0000 315.60 19807 0.4547 317.20 43381 0.9959 318.80 70859 1.6267 314.10 1238 0.0284 315.70 21045 0.4831 317.30 44933 1.0315 318.90 72742 1.6699 314.20 2476 0.0568 315.80 22283 0.5115 317.40 46485 1.0671 319.00 74625 1.7132 314.30 3714 0.0853 315.90 23521 0.5400 317.50 48037 1.1028 319.10 76508 1.7564 314.40 4952 0.1137 316.00 24759 0.5684 317.60 49589 1.1384 319.20 78391 1.7996 314.50 6190 0.1421 316.10 26311 0.6040 317.70 51140 1.1740 319.30 80274 1.8428 314.60 7428 0.1705 316.20 27863 0.6396 317.80 52692 1.2096 319.40 82157 1.8861 314.70 8666 0.1989 316.30 29414 0.6753 317.90 54244 1.2453 319.50 84040 1.9293 314.80 9904 0.2274 316.40 30966 0.7109 318.00 55796 1.2809 319.60 85923 1.9725 314.90 11142 0.2558 316.50 32518 0.7465 318.10 57679 1.3241 319.70 87806 2.0157 315.00 12379 0.2842 316.60 34070 0.7821 318.20 59562 1.3673 319.80 89688 2.0590 315.10 13617 0.3126 316.70 35622 0.8178 318.30 61445 1.4106 319.90 91571 2.1022 315.20 14855 0.3410 316.80 37174 0.8534 318.40 63328 1.4538 320.00 93454 2.1454 315.30 16093 0.3695 316.90 38726 0.8890 318.50 65211 1.4970 315.40 17331 0.3979 317.00 40277 0.9246 318.60 67093 1.5403 315.50 18569 0.4263 317.10 41829 0.9603 318.70 68976 1.5835 12/1/99 10 :57 :49 am NL Olson & Assoc . Inc . page 4 North Mason Fiber Company Final Storm Report Developed Conditions - Basin B STAGE DISCHARGE TABLE DISCHARGE LIST ID No. dis13 Description: Infiltration Rate Discharge STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---Cfs-- ------- (ft) ---Cfs-- ------- (ft) ---cfs-- ------- (ft) ---Cfs-- ------- 314.00 0.3000 315.60 0.4280 317.20 0,5860 318.80 0.7660 314.10 0.3080 315.70 0.4360 317.30 0.5965 318.90 0.7780 314.20 0.3160 315.80 0.4440 317.40 0.6070 319.00 0.7900 314.30 0.3240 315.90 0.4520 317.50 0.6175 319.10-- 0.8020 314.40 0.3320 316.00 0.4600 317.60 0.6280 319.20 0.8140 314.50 0.3400 316.10 0.4705 317.70 0.6385 319.30 0.8260 314.60 0.3480 316.20 0.4810 317.80 0.6490 319.40 0.8380 314.70 0.3560 316.30 0.4915 317.90 0.6595 319.50 0.8500 314.80 0.3640 316.40 0.5020 318.00 0.6700 319.60 0.8620 314.90 0.3720 316.50 0.5125 318.10 0.6820 319.70 0.8740 315.00 0.3800 316.60 0.5230 318.20 0.6940 319.80 0.8860 315.10 0.3880 316.70 0.5335 318.30 0.7060 319.90 0.8980 315.20 0.3960 316.80 0.5440 318.40 0.7180 320.00 0.9100 315.30 0.4040 316.90 0.5545 318.50 0.7300 315.40 0.4120 317.00 0.5650 318.60 0.7420 315.50 0.4200 317.10 0.5755 318.70 0.7540 v 12/1/99 10 :57 :52 am NL Olson & Assoc. Inc. page 5 North Mason Fiber Company, Final Storm Report Developed Conditions - Basin B ----------------- LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAR-> OUTFLOW STORAGE <--------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id (cfs) VOL (cf) 100-year Storm Event ......... 0.00 6.85 pondB disB 318.77 8 0.76 70221.84 cf 6-month Storm Event .......... 0.00 2.15 pondB disB 314.95 9 0.38 11748.12 cf 12/1/99 11 : 0 :21 am NL Olson & Assoc . Inc . page 1 North Mason Fiber Company Final Storm Report Biofiltration Swale B Contributing Area --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID: BDB-100 NAME : Basin B Dev. 100-year Bioswale SBUH METHODOLOGY TOTAL AREA. . . . . . . : 4 . 91 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 7 . 00 inches AREA. . : 0 . 53 Acres 4 . 38 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 98 . 00 TC. . . . : 47 . 34 min 6 . 92 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 225 . 00 ns : 0 .4000 p2yr: 3 . 65 s : 0 . 0133 TcReach - Shallow L: 300 . 00 ks :27 . 00 s : 0 . 0100 TcReach - Channel L: 36 . 00 kc :21 . 00 s : 0 . 0200 impTcReach - Sheet L: 300 . 00 ns : 0 . 0110 p2yr: 3 . 65 s : 0 . 0108 impTcReach - Shallow L: 145 . 00 ks : 27 . 00 s : 0 . 0100 impTcReach - Channel L: 336 . 00 kc :21 . 00 s : 0 . 0111 PEAK RATE : 6 . 50 cfs VOL: 2 .56 Ac-ft TIME : 480 min BASIN ID: BDB-6m NAME : Basin B Dev. 6-month Bioswale SBUH METHODOLOGY TOTAL AREA. . . . . . . : 4 .91 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 2 .34 inches AREA. . : 0 . 53 Acres 4 . 38 Acres TIME INTERVAL . . . . : 10 . 00 min CN. . . . : 55 . 00 98 . 00 TC. . . . : 47 . 34 min 6 . 92 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 225 . 00 ns : 0 .4000 p2yr: 3 . 65 s : 0 . 0133 TcReach - Shallow L: 300 . 00 ks :27 . 00 s : 0 . 0100 TcReach - Channel L: 36 . 00 kc :21 . 00 s : 0 . 0200 impTcReach - Sheet L: 300 . 00 ns : 0 . 0110 p2yr: 3 . 65 s : 0 . 0108 impTcReach - Shallow L: 145 . 00 ks :27 . 00 s : 0 . 0100 impTcReach - Channel L: 336 . 00 kc:21 . 00 s : 0 . 0111 PEAK RATE: 2 . 08 cfs VOL: 0 . 77 Ac-ft TIME : 480 min Trapezoidal Channel Analysis & Design Open Channel - Uniform flow Worksheet Name : N . Mason Fiber #5089 Comment : 6-month Biofiltration Swale B Design Solve For Depth Given Input Data : Bottom Width. . . . . 8 . 50 ft Left Side Slope. . 3 . 00 : 1 (H :V) Right Side Slope . 3 . 00 : 1 (H :V) Manning ' s n. . . . . . 0 . 200 Channel Slope . . . . 0 . 0100 ft/ft Discharge . . . . . . . . 1 . 04 cfs Computed Results : Depth. . . . . . . . . . . . 0 . 33 ft Velocity . . . . . . . . . 0 . 33 fps Flow Area . . . . . . . . 3 . 15 sf Flow Top Width. . . 10 . 49 ft Wetted Perimeter . 10 . 60 ft Critical Depth. . . 0 . 08 ft Critical Slope. . . 1 . 3895 ft/ft Froude Number . . . . 0 . 11 ( flow is Subcritical ) Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods , Inc . * 37 Brookside Rd * Waterbury , Ct 06708 Trapezoidal Channel Analysis & Design Open Channel - Uniform flow Worksheet Name : N . Mason Fiber #5089 Comment : 100-year Biofiltration Swale B Design Solve For Depth Given Input Data : Bottom Width. . . . . 8 . 50 ft Left Side Slope. . 3 . 00 : 1 (H :V) Right Side Slope . 3 . 00 : 1 (H :V) Manning ' s n. . . . . . 0 . 035 Channel Slope . . . . 0 . 0100 ft/ft Discharge . . . . . . . . 3 . 25 cfs Computed Results : Depth. . . . . . . . . . . . 0 . 23 ft Velocity . . . . . . . . . 1 . 52 fps Flow Area . . . . . . . . 2 . 14 sf Flow Top Width. . . 9 . 89 ft Wetted Perimeter . 9 . 97 ft Critical Depth. . . 0 . 16 ft Critical Slope. . . 0 . 0336 ft/ft Froude Number . . . . 0 . 58 ( flow is Subcritical ) open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods , Inc. * 37 Brookside Rd * Waterbury, Ct 06708 Circular Channel Analysis & Design Solved with Manning ' s Equation Open Channel - Uniform flow Worksheet Name: N . Mason Fiber #5089 Comment : Basin B Pipe Capacity Verification 24" Dia . Solve For Actual Depth Given Input Data : Diameter . . . . . . . . . . 2 . 00 ft Slope . . . . . . . . . . . . . 0 . 0200 ft/ft Manning' s n. . . . . . . 0 . 015 Discharge . . . . . . . . . 6 . 50 cfs Computed Results : Depth. . . . . . . . . . . . . 0 . 66 ft Velocity . . . . . . . . . . 7 . 21 fps Flow Area . . . . . . . . . 0 . 90 sf Critical Depth. . . . 0 . 90 ft Critical Slope . . . . 0 . 0063 ft/ft Percent Full . ... . . . 32 . 94 % Full Capacity. . . . . 27 . 73 cfs QMAX @ . 94D . . . . . . . . 29 . 83 cfs Froude Number . . . . . 1 . 83 (flow is Supercritical ) Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods , Inc . * 37 Brookside Rd * Waterbury, Ct 06708