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Home My WebLink AboutDDW-2025-010587Prepared For: Bicknell Town and Wayne County Prepared By: Jack Jeppson, EIT Reviewed By: Kelly Chappell, PE Hydraulic Model Summary October 2025 10675582-2202 KELLY L. CHAPPELLLICENSED PROFESS IONAL ENGINEER STATE OF UTAH Hydraulic Model Summary Table of Contents Glossary of Technical Terms ........................................................................................................ i Abbreviations and Units ............................................................................................................ xii Executive Summary .................................................................................................................. xv Section 1 Introduction ................................................................................................................ 1 1.1 Method and Hydraulic Model Information ............................................................................. 1 1.1.1 Hydraulic Model Software .............................................................................................. 1 1.1.2 Hydraulic Model Input .................................................................................................... 1 Section 2 Hydraulic Model ......................................................................................................... 1 2.1 Site Information .................................................................................................................... 2 2.2 Hydraulic Model Results....................................................................................................... 2 2.2.1 Fire Flow Requirements ................................................................................................. 2 2.2.2 Optional Replacement.................................................................................................... 2 2.2.3 Results and Analysis ...................................................................................................... 2 Section 3 Conclusion ................................................................................................................. 3 Figures Figure 1 EX-100 Water Model Information w/o Replacement ..................................................... 1 Figure 2 EX-200 Water Model Information w Replacement ........................................................ 2 Tables Table 2-1 Available Fire Flow Results ........................................................................................ 3 Appendices Appendix A Exhibits Hydraulic Model Summary Hydraulic Model Summary i Glossary of Technical Terms 80th Percentile Rainfall Event Storm event in which precipitation is greater than or equal to 80 percent of all storm events averaged over a given period of record. Average Daily or Day Demand The average yearly demand volume expressed as a flow rate. Demand is typically used in irrigation or drinking water terminology. Average Daily or Day Flow The average yearly flow volume expressed as a flow rate. Term typically used in wastewater terminology. Average Yearly Demand Amount of water delivered to consumers by a public water system during a typical year. Demand is typically used in irrigation or drinking water terminology. Bonds Fixed-income instrument representing a loan made by an investor to a borrower (typically corporate or governmental). Bonds are used by companies, municipalities, states, and sovereign governments to finance projects and operations. Build-Out The maximum number of ERCs or EDUs allowed by the planning jurisdiction in its service area. Buy-in Costs Depreciated costs for municipal or service district assets which have excess capacity and can be contributed to existing or future development. Capital Facilities Plan A plan to assist a jurisdiction to use its funding wisely and efficiently to maximize funding opportunities. A capital facilities plan will assist in determining needs, prioritizing projects, coordinating related projects, and applying for load, bonds, and grant opportunities. Hydraulic Model Summary ii Collection System Wastewater system consisting of manholes, gravity pipes, force mains, interceptors, trunk lines, lift stations, and appurtenances. Collector Line Sanitary sewer line which receives wastewater flow from lateral sewer lines and conveys flow to a trunk line or an interceptor line. Connection Fee Fee paid to utility purveyor from a developer or customer for its cost of physically connecting the developer or customer to the utility purveyor’s utility system. Cost Estimate Typically an Engineer’s Estimate of Probably Costs for a project improvement based on recently bid projects and current construction climate. A cost estimate may include design fees, permitting, administrative costs, and contingency. Curve Number Empirical parameter used in hydrology for predicting storm water runoff potential for a given drainage area based on land use, soil group, and soil moisture derived by the National Resources Conservation Service (NRCS). Term typically used in storm water terminology. Debt Service Money required to cover the payment of interest and principal on a loan or other debt for a particular time period. Debt Service Coverage Ratio Debt service coverage ratio is measured by comparing the operating cash (revenues less operating expenses) to annual debt service obligations before capital costs. Demand The drinking water flow rate or volume consumed by water system users. Hydraulic Model Summary iii Demographics Characteristics of human population and population segments. Detention Term typically used in storm water terminology to define a storm water storage site which stores and releases storm water at a controlled discharge rate. Disinfection A process which inactives pathogenic organisms in water by chemical oxidants or equivalent agents. Distribution System Drinking water system’s network of pipes, valves, fitting, and appurtenances. Drinking Water Water suitable to be ingested by humans. Sometimes referred to as Culinary or Potable Water. Dwelling Unit(s) Dwelling Unit (DU) is a structure or the part of a structure used as a home, residence, or sleeping place by one person who maintains a household or by two or more persons who maintain a common household. Equivalent Residential Connection(s), Dwelling Unit(s) or Residential Unit(s) An ERC, EDU, or ERU is a unit of measurement used to compare water demand from non- residential connections to residential connections. Water use criteria from source (wells and springs) and metered data are established based on average demand or consumption by residential connections. This is compared with non-residential uses. Excess Capacity Excess capacity used for engineering purposes is when the demand is less than capacity. An example of excess capacity is when the water demand (consumption) of drinking water system users is less than the drinking water system supply. Fee Stabilization Charge (Credit) Hydraulic Model Summary iv Payment amount of principal and interest on a revenue bond after the study or plans planning period, which should not be charged to new development in the planning period. Fixture Unit A unit of measure expressing the hydraulic loading imposed by any sanitary fixture on the system of pipe work to which it discharges. Fixture units are typically defined in the International Plumbing Code (IPC). Fire Flow Available flowrate of water supply for firefighting with a residual pressure of 20 psi. Typically measured as a rate of flow (gpm) for a specific period of time or duration (hours). Flood Hazard Zone Flood Hazard Zone is an area identified on a Flood Insurance Rate Map (FIRM) which specifies a Base Flood Elevation (BFE) or flood depth. Head Also referred to as Pressure Head is a measurement of water pressure in a hydraulic setting expressed as feet of water. One (1) lbs per square inch (psi) of head equals 2.31 feet. Head Loss Measurement of energy dissipated in a fluid system due to friction along the length of a pipe or hydraulic system, and those due to fittings, valves and other system structures. HEC Computer software for hydrologic engineering and planning analysis. HEC-RAS Computer program which models the hydraulics of water flow through natural rivers and channels. Hydrology Scientific study of the properties, distribution, and effects of water on the earth’s surface, in the soil and underlying rocks, and in the atmosphere. Hydraulic Model Summary v Hydrologic Soil Group Natural Resource Conservative Service (NRCS) classification system in which soils are categorized into four (4) runoff potential groups. This groups consist of soil groups A, B, C, or D. Indoor Use Hydraulic loading imposed by any sanitary fixture on the system of pipe work to which it discharges inside a building. Infiltration Process by which water enters the soil and recharges streams, lakes, rivers, and underground aquifers. Term typically used in storm water terminology. Infiltration Rate Flow rate by which water enters the soil and recharges streams, lakes, rivers, and underground aquifers. Typically, specified in inches per hour. Term typically used in storm water terminology. Inflation Rate at which prices for goods and services increases. Interceptor Lines Major sanitary sewer line that receives flow from trunk sanitary sewer lines. Interest Amount paid to borrow money or the cost charged to lend money. Interest is most often reflected as an annual percentage of the amount of a loan. Impact Fee Payment of money imposed upon new development activity as a condition of development approval to mitigate the impact of the new development on public infrastructure. Impact Fee Analysis Hydraulic Model Summary vi The written analysis of each impact fee required by Utah Code Section 11-36a-303. Impact Fee Facilities Plan Plan required by Utah Code Section 11-36a-301. Impervious Term typically used in storm water terminology to define an area which is impervious such as asphalt pavement or a concrete sidewalk. Level of Service Defined performance standard or unit of demand for each capital component of a public facility within a service area. LID Low Impact Development is a storm water management strategy which seeks to mitigate the impacts of increased runoff and storm water pollution by managing runoff as close to its source as possible. Manning’s n Unitless coefficient which represents the roughness or friction applied to the flow of a conduit or a channel. Master Plan Dynamic long-term planning document providing a conceptual layout to guide future growth and development. Major Head losses Major head losses or friction losses is the loss of pressure or “head” in pipe flow due to the effect of the fluid’s viscosity near the surface of the pipe or duct. Minor Head losses Minor head losses are local pressure losses or pressure drops of various hydraulic elements such as bends, fittings, valves, elbows, tees or heated channels. Hydraulic Model Summary vii Multi-Unit Typically a dwelling unit with multiple units such as an apartment building or a duplex. NOAA ATLAS 14 Precipitation Data Point precipitation frequency estimates for a specific area in the United States available on NOAA’s website. Non-Residential A non-residential use such as a warehouse, commercial building, or business. Occurrence Term used in storm water terminology to estimate the frequency of a storm water event. Other Residential Encompasses other residential not defined specifically in the plan or study. Outdoor Use Hydraulic loading imposed on the system typically by an irrigation system. Peak Day Demand Amount of water utilized by a water supplier on the day of highest consumption, generally expressed in gallons per day (gpd) or millions of gallons per day (MGD). Demand is typically used in irrigation or drinking water terminology. Peak Day Flow Amount of wastewater utilized by a wastewater supplier on the day of highest consumption, generally expressed in gallons per day (gpd) or millions of gallons per day (MGD). Peak Discharge Maximum rate of flow during a storm event. Term typically used in storm water terminology. Peaking Factors Ratio of a peak day or instantaneous flow/demand to the average day or daily flow/demand. Hydraulic Model Summary viii Peak Inflow Highest inflow of wastewater into a wastewater treatment facility. Peak Instantaneous Demand Calculated or estimated highest demand which can be expected through any water main of the distribution network of a water system at any instant in time, generally expressed in gpm or cfs. Peak Instantaneous Flow Calculated or estimated highest flowrate which can be expected through any wastewater collection system at any instant in time, generally expressed in gpm or cfs. Peak Rainfall Depth The point at which the amount of rain received is at its highest depth. Percolation Rate Flow rate by which water enters the soil and recharges streams, lakes, rivers, and underground aquifers. Typically, specified in minutes per inch. Term typically used in storm water terminology. Pervious Term typically used in storm water terminology to define an area which is pervious or allows storm water to infiltrate into the soil such as a parking strip or lawn. Planning Period The period of time, typically in years, used in a plan. A planning period of 10-years is typically used in Impact Fee Facilities Plans. Master or General Plans may use planning periods from 20 to 50 years. Pressure Reducing Valve Valve provided to reduce pressure in a water distribution system. Typically, used to reduce pressure greater than 100 psi to 50 – 65 psi depending on specific distribution system requirements. Pressure Zone Hydraulic Model Summary ix A pressure zone in a distribution system is established with a minimum and maximum pressure range which is maintained without the use of ancillary control equipment (e.g. booster pumps, pressure reducing valves, etc.). Maximum static pressures in a typical drinking water pressure zone are 100 to 120 psi with minimum static pressures from 50 to 65 psi. Professional Expenses Expenses of a professional consultant. An example is engineering design and construction administrative fees from an engineering company. Proportionate Share Cost of public facility improvements which are roughly proportionate and reasonably related to the service demands and needs of any development activity. Retention Term typically used in storm water terminology to define a storm water storage site which retains storm water without releasing at a controlled discharge rate and instead infiltrates stored storm water into the ground. Runoff Precipitation which does not soak or absorb into the soil surface. Runoff Coefficients Percentage of precipitation leaving a particular site as runoff. Safety Factor Engineering term utilized to describe how much stronger a system or structure is than it is required to be to fulfil its purpose under expected conditions. SCS Method Soil Conservation Service (SCS) Method is a hydrologic modeling method for computing the volume of surface runoff for a given rainfall event from small agricultural, forest, and urban watersheds. Service Area Hydraulic Model Summary x Geographic area designated by an entity which a facility, or a defined set of facilities, provides service within the area. Single Family Residence used by a single private family which serves no other purpose. Source Term used in irrigation or drinking water terminology to specify where the supply of water originates. Examples include groundwater wells or springs. Static Pressure The pressure exerted by a liquid or gas, especially water or air, on a body at rest. Storm and Sanitary Analysis Comprehensive hydrology and hydraulic analysis application which assists in planning and design of storm water and sanitary sewer systems. Storm Event Amount of precipitation which occurs during a specific duration and recurrence interval for the location of the storm event. An example is a 100-year storm event during a 24-hour duration. Surplus Capacity The amount of surplus or excess capacity a system has available to future development. SWMM Method Storm Water Management Model (SWMM) Method is used throughout the world for planning, analysis and design related to storm water runoff, combined and sanitary sewers, and other drainages. SWMM is a Windows-based, open source, desktop program. Time of Concentration Time required for water to flow from the most remote point in a watershed to the point of interest within the watershed. It is a function of topography, geology and land use within the watershed and is computed by summing all the travel times for consecutive components of the drainage conveyance system. Hydraulic Model Summary xi Total Dynamic Head Total Dynamic Head is the total equivalent height that water needs to be pumped or lifted vertically while also factoring in the friction losses of the pipe and minor head losses in valves and fittings. TR-55 Technical Release 55 (TR-55) presents simplified procedures to calculate storm runoff volume, peak rate of discharge, hydrographs, and storage volumes required for storm water detention or retention. Transmission Pipeline For drinking water or irrigation, a transmission pipeline is typically defined as the pipe from a storage reservoir to the distribution system. A transmission pipeline typically does not have any user water connections. Trunk Line Sewer line which receives wastewater flow from the collector sanitary sewer lines and conveys this wastewater either to an interceptor line or a wastewater treatment or reclamation facility. Waterline A line formed by the surface of the water on a structure. Water Line Pipe or conduit which contains and conveys water. Water Right The right to use water diverted at a specific location on a water source, and putting it to recognized beneficial uses at set locations. Water Wise or Water-Wise Generally a functional, attractive, and easily maintained landscape in its natural surroundings. A water wise landscape helps conserve water. Note: Local jurisdiction may have specific definition of water wise landscaping. Hydraulic Model Summary xii Abbreviations and Units ac acre [area unit of measurement] ac-ft acre-foot (1 acre-foot = 325,851 gallons) [volume unit of measurement] AWWA American Water Works Association BFE Base Flood Elevation BMP Best Management Practices C Runoff Coefficient CN Curve Number(s) CFP Capital Facilities Plan cfs cubic feet per second [flow rate unit of measurement] cfs/acre cubic feet per acre [flow rate per area unit of measurement] CLOMR Conditional Letter of Map Revision CMP Corrugated Metal Pipe d/D depth to diameter ratio DIP Ductile Iron Pipe DEQ Department of Environmental Quality DSCR Debt Service Coverage Ratio DU Dwelling Unit(s) EDU Equivalent Dwelling Unit(s) Ensign Ensign Engineering and Land Surveying EPA U.S. Environmental Protection Agency ERC Equivalent Residential Connection(s) ERU Equivalent Residential Units(s) FEMA Federal Emergency Management Agency FIRM Flood Insurance Rate Map(s) ft foot [length unit of measurement] ft/s or fps feet per second [velocity unit of measurement] FU Fixture Unit gal gallons [volume unit of measurement] gpd gallons per day [flow rate unit of measurement] gpm gallons per minute [flow rate unit of measurement] HDPE High-density Polyethylene [material used for various building materials] Hydraulic Model Summary xiii HDS Hydrodynamic Separator HEC Hydrologic Engineering Center HEC-RAS Hydrologic Engineering Center – River Analysis System hr hour [time unit of measurement] IBC International Building Code ID Inside Diameter IFC International Fire Code IFFP Impact Fee Facilities Plan IPC International Plumbing Code i Average Rainfall Intensity (inches per hour) I&I Inflow and Infiltration in. inch [length unit of measurement] L Length (ft) LID Low Impact Development LOMA Letter of Map Amendment LOMR-F Letter of Map Revision-Based on Fill LOS Level of Service MG million gallons [volume unit of measurement] MGD millions of gallons per day [flow rate unit of measurement] mi mile [length unit of measurement] min minute [time unit of measurement] MP Master Plan NOAA National Oceanic Atmospheric Administration NOI Notice of Intent NOT Notice of Termination NRCS Natural Resources Conservation Service OSLI Office of State Lands and Investments[R2] PF Peaking Factor PRV Pressure Reducing Valve psi pounds per square inch [pressure unit of measurement] PVC Polyvinyl Chloride [type of plastic pipe] Q Flow Rate or Peak Rate of Runoff (cubic feet second) RCP Reinforced Concrete Pipe s second [time unit of measurement] Hydraulic Model Summary xiv SCADA Supervisory Control And Data Acquisition SCS Soil Conservation Service SF Safety Factor SR State Route SSA Storm and Sanitary Analysis SWMP Storm Water management Program SWPPP Storm Water Pollution Prevention Plan Tc Time of Concentration UAC Utah Administrative Code UCEA Utah City Engineers Association V Velocity (fs/s or fps) WSFU Water Supply Fixture Unit WW Wastewater WWTF Wastewater Treatment Facility WWRF Wastewater Reclamation Facility yr year [time unit of measurement] Hydraulic Model Summary xv Executive Summary This report presents the development, analysis, and results of the hydraulic modeling for the Bicknell Town water distribution system and the proposed improvements for the project site located near 700 S and 350 E in Bicknell, Utah 84715. The hydraulic model was developed using Bentley WaterCAD 2021, incorporating detailed data on pipe materials, lengths, elevations, and slopes, along with tank sizes and locations surveyed by Ensign Engineering. The Hazen-Williams method was used to calculate head loss and assess system performance under existing, future, and proposed conditions. Pipe friction coefficients were assigned as 150 for PVC and 130 for ductile iron. Water demands were applied to nodes throughout the system based on Equivalent Residential Connections (ERCs) for both peak day and peak instantaneous conditions. The hydraulic model results indicated that the proposed 8-inch PVC waterline along 350 E would not independently meet the standard minimum fire flow requirement of 1,500 gpm. However, fire flow results in the range of 1,200 gpm to 1,500 gpm will be acceptable according to the Wayne County Fire Official. Due to this, an optional improvement was identified to enhance fire flow capacity—replacing the existing 4-inch pipe crossing SR-24. With this replacement, fire flows increased, as shown in Table 2-1. In conclusion, the proposed design meets acceptable performance standards and may proceed as planned. However, incorporating the optional replacement would provide additional fire flow capacity, enhance system reliability, and better ensure compliance with state fire flow requirements. Hydraulic Model Summary 1 Section 1 Introduction 1.1 Method and Hydraulic Model Information 1.1.1 Hydraulic Model Software The distribution system computer model was developed in Bentley WaterCAD 2021 which allowed the water system to be graphically input into the program. Once the system pipes, and storage tanks were in the model, the attributes of each individual component were entered. The details included pipe material, length of pipes, elevation of the ends of each pipe, slope of each pipe. The storage tank locations, size, and elevation were based on survey data collected by Ensign Engineering. Bicknell Town water system was analyzed using the Hazen-Williams method. This method allowed for the head loss (friction loss) for each pipe, valve, and fitting to be calculated, and is a commonly used method for water system master planning. Once the model was fully developed, the existing, future and proposed systems were then analyzed to determine the current systems performance and assess problem areas and potential weaknesses as well as proposed solutions. 1.1.2 Hydraulic Model Input The water system for Bicknell Town was input into the Hydraulic Model. Most of the pipes in the system are PVC, which are assigned a Hazen-Williams coefficient of friction of 150. Ductile Iron pipes are given a value of 130. The demand for the model and each node is the Total Demand (both indoor and outdoor) for Peak Day and Peak Instantaneous demands. Nodes were assigned to every intersection of pipe where a fire hydrant was nearby, as well as other locations that may be of concern. Each Node was assigned the demand according to how many ERCs would be serviced from said node. Each node received demands for Peak Day and Peak Instantaneous for existing conditions and for future demand requirements. Section 2 Hydraulic Model Hydraulic Model Summary 2 2.1 Site Information The subject site is located around 700 S on 350 E on the east side of the road in Bicknell, UT 84715. The project will include a waterline that runs along 350 E. Once at the subject site, a looped waterline to service lots is proposed. 2.2 Hydraulic Model Results 2.2.1 Fire Flow Requirements The hydraulic model results revealed the proposed waterline for the subject site meets fire flows within the 1,200 to 1,500 gpm range at a minimum pressure of 20 psi during a peak day demand and a maximum velocity through any pipe in the system of less than 10 feet per second. The purpose of these constraints is to insure that at the require fire flow, the system doesn’t experience a negative pressure or vacuum at any location and to prevent damage to the system as a result of high velocities and cavitation. 2.2.2 Optional Replacement The proposed waterline to the subject site is all 8” PVC. An optional improvement to the proposed waterline will increase the available fire flow. This improvement is replacement is found replacing an existing 4” pipe crossing SR-24 to 8”. This would improve all fire flows to above 1,500 gpm and may be considered in the future as a future improvement. 2.2.3 Results and Analysis Taking into account the requirements described in Section 2.2.1, the results displaying the available fire flow can be shown in Table 2-1. The Junctions can be seen in Appendix A. Hydraulic Model Summary 3 Table 2-1 Available Fire Flow Results Available Fire Flow Results Junction Elevation Without Replacement With Replacement J-67 7,099 1,918 2,473 J-66 7,096 1,406 2,636 J-68 7,070 1,406 1,532 J-69 7,084 876 876 J-112 7,051 1,406 1,532 J-113 7,041 1,406 1,532 J-114 7,067 1,406 1,532 J-115 7,075 1,406 1,532 J-116 7,082 1,406 1,532 J-117 7,066 1,406 1,532 According to Section 2.2.1, the flows between 1,200 and 1,500 gpm are considered acceptable, but cautionary. Therefore, it would be acceptable to move forward with the project as designed. Junction 69 and its respective lower values are from the service feeding the Wayne Community Center and not part of the main line. Section 3 Conclusion The proposed design results are in the acceptable and cautionary range of 1,200 gpm to 1,500 gpm. This means that it would be acceptable to proceed as planned with the proposed design. It’s worth noting that the optional replacement of a 4” line crossing SR-24 could be considered in the future to increase fire flow above 1,500 for all proposed connections. Should the structures built in the planned industrial park require higher fire flows than those assumed in this analysis, that improvement could be considered. Hydraulic Model Summary Appendix A Exhibits Figure 1 EX-100 Water Model Information w/o Replacement Hydraulic Model Summary Figure 2 EX-200 Water Model Information w Replacement