Flood Studies Work Plan
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File Date: Fri Sep 22 05:19:59 2006
This PDF technical document describes, in general terms, the hydrologic work necessary for a flood study.
Flood Studies and Maps
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File Date: Fri Sep 22 05:19:43 2006
Flood maps are a vital part of a floodplain management program, so it is important to understand how the maps are made and to be familiar with the information that is available within the accompanying flood study. This PDF technical document provides an overview of flood study terms and how studies and maps are prepared.
Download Documentation on Detention Pond Design (PDF File)
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File Date: Fri Sep 22 07:21:13 2006
The traditional design of storm drainage systems has been to collect and convey storm runoff as rapidly as possible to a suitable location where it can be discharged. As areas urbanize this type of design may result in major drainage and flooding problems downstream. Under favorable conditions, the temporary storage of some of the storm runoff can decrease downstream flows and often the cost of the downstream conveyance system. Detention storage facilities can range from small facilities contained in parking lots or other on-site facilities to large lakes and reservoirs. This PDF file provides a general design criteria for detention/retention storage basins as well as procedures for performing preliminary and final sizing and reservoir routing calculations.
Download Guide for Selecting Manning's Roughness Coefficients (PDF File)
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File Date: Fri Sep 22 06:36:11 2006
This PDF file contains documentation on how to select Manning's Roughness Coefficient. Most hydraulic computations related to indirect estimates of discharge require an evaluation of the roughness characteristics of the channel. This document contains photographs and data for a wide range of channel conditions that can be used to select roughness coefficients for other natural channels.
Download Manning's Roughness Coefficient Guide (PDF File)
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File Date: Fri Sep 22 09:08:34 2006
Most hydraulic computations related to indirect estimates of discharge require an evaluation of the roughness characteristics of the channel. This document contains photographs and data for a wide range of channel conditions that can be used to select roughness coefficients for other natural channels.
Download National Engineering Hydrology Handbook (PDF File)
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File Date: Tue Mar 14 03:40:37 2006
The NRCS National Engineering Handbook (NEH) is intended primarily for Natural Resources Conservation Service (NRCS) engineers and technicians. It presents material needed to carry out NRCS responsibilities in natural resources conservation and flood prevention.
Download Documentation on Detention Pond Design (PDF)
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File Date: Tue Mar 14 03:40:41 2006
This files contains lecture notes from the University of Texas on detention pond design.
Download Documentation on Design Storm Development (PDF)
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File Date: Tue Mar 14 03:40:40 2006
This file contains lecture notes from the University of Texas on design storm development.
Download Documentation on Culvert Design (PDF)
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File Date: Tue Mar 14 03:40:39 2006
This file contains lecture notes from the University of Texas on culvert design.
Download Urban Drainage Design Manual
Hydraulic Engineering Circular No. 22 (PDF File)
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File Date: Tue Mar 14 03:46:44 2006
This design manual provides a comprehensive and practical guide for the design of storm drainage systems associated with transportation facilities. Design guidance is provided for the design of storm drainage systems which collect, convey, and discharge stormwater flowing within and along the highway right-or-way. Methods and procedures are given for the hydraulic design of storm drainage systems. Design methods are presented for evaluating rainfall and runoff magnitude, pavement drainage, gutter flow, inlet design, median and roadside ditch flow, structure design, and storm drain piping. Procedures for the design of retention facilities and stormwater pump stations are also presented, along with a review of urban water quality practices. A summary of related public domain computer programs is also provided.
Download Hydraulic Design of Highway Culverts
Hydraulic Design Series No. 5 (PDF File)
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File Date: Tue Mar 14 03:42:38 2006
This document provides comprehensive culvert design material. Culvert design methods are presented for both conventional culverts and culverts with inlet improvements. Storage routing techniques are included which permit the designer to account for ponding effects upstream of the culvert. Unique culvert applications, erosion and sediment control, debris control, structural aspects, and long span culverts are discussed. Inlet control, outlet control, and critical depth design charts, are included for a variety of culvert sizes, and shapes, and materials. Dimensionless culvert design charts are also provided for the design of culverts.
Download Estimation of Green-Ampt Infiltration Parameters used in StromPack (PDF File)
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File Date: Tue Mar 14 03:41:03 2006
This document provides estimation of Green-Ampt Infiltration Parameters used in StormPack.
Download USDA Engineering Field Handbook Chapter 19 - Hydrology Tools for Wetland Determination (PDF File)
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File Date: Tue Mar 14 03:40:50 2006
This chapter of the Engineering Field Handbook presents seven tools or procedures to use in the evaluating the hydrology of potential wetlands. Each tool is used in one or more states to assist in the determination of wetlands. These tools are analytical techniques that can be used to supplement the documentation of wetland hydrology determination.
Download USDA Ponds - Planning, Design, Construction Handbook (PDF File)
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File Date: Tue Mar 14 03:48:35 2006
This handbook describes the requirements for building a pond. It is useful to the landowner for general information and serves as a reference for the engineer, technician, and contractor.
Download Curve Numbers Tech Papers - The Origin and Derivation of Ia/S in the Runoff Curve Number System (PDF File)
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File Date: Tue Mar 14 03:40:41 2006
In response to legislative authorities of 1944 and 1954, the Natural Resources Conservation Service (NRCS), formally the Soil Conservation Service (SCS), began the development of a Hydrology Guide for use in watershed planning. This effort became Section 4 "Hydrology" of the National Engineering Handbook. This development created the SCS Runoff Curve Number Equation. This paper explains the development of the relationship of Ia to S.
Download Curve Numbers Tech Papers - Hydrologic Soil Group Assignment (PDF File)
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File Date: Tue Mar 14 03:46:45 2006
Assignment of soils to hydrologic soil groups has been based on published criteria subjectively interpreted and applied by soil scientists. As a result hydrologic soil group placement for any given soil lacks consistency of method and correlation to the respective soil's physical properties. A method of placing soil into hydrologic soil groups was developed using fuzzy systems techniques. This method consists of a set of fuzzy system rules and evaluations that establish a consistency in the interpretation of hydrologic soil group criteria. The fuzzy system placement of soil into a hydrologic soil group correlates well with previously established placements. This approach also identified those soils that may have been improperly placed in a given hydrologic soil group and those that have insufficient data to make a proper group placement.
Download Lag Tech Papers - Lag Time Characteristics of Small Watersheds in the U.S. (PDF File)
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File Date: Tue Mar 14 03:48:03 2006
Lag time, defined as the time from the centroid of rainfall excess to the centroid of direct runoff, was evaluated for over 50,000 rainfall-runoff events in 168 small watersheds in the United States ranging from 0.243 to 3,490 acres. In most watersheds a stable value of lag time was observed for the larger storms, with peak flow the variable that best showed this tendency. The watersheds were divided into groups to explain the variation of lag time between watersheds. The groups that had a significant effect in the regression equation were geographical regions, watershed management practices, and the stability of the lag time value for the bigger storms. Separation of watersheds by land use and hydrologic behavior did not significantly improve the regression analyses.
Download Curve Numbers Tech Papers - Local Sources for Runoff Curve Numbers (PDF File)
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File Date: Tue Mar 14 03:40:37 2006
Design rainfall-runoff hydrology and environmental impact analysis draws heavily on the Curve Number method. The centerpiece of it is the coefficient "Curve Number", a measure of a watershed's hydrologic response potential, and usually selected from handbooks based on soils, cover, and land use.
Download Curve Numbers Tech Papers - Site and Cover Effects on Event Runoff, Jornada Experimental Range, New Mexico (PDF File)
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File Date: Tue Mar 14 03:48:46 2006
Event rainfall depth, runoff depth, and periodic cover density measurements were taken for a total of 21 plots (2m x 2m) at 5 different locations on the National Science Foundation Jornada Long-Term Ecological Research Site in southern New Mexico. Runoff properties are characterized by plot, plot group, and site using Curve Number (CN) analysis.
Download Curve Numbers Tech Papers - Secondary Influences in Curve Number Rainfall - Runoff (PDF File)
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File Date: Tue Mar 14 03:48:46 2006
The secondary influences on direct runoff depth are studied for a number of small agricultural watersheds in the United States. A variation of Curve Number function is used as a basis for primary rainfall depth response. Using 1830 events from 25 small watersheds with effective rainfall greater than 1.00 inch, the effects of prior rainfall (including initial abstraction), intensity, and storm distribution (pattern index) on departures from the fitted rainfall effects are evaluated.
EPA SWMM 4.4 User Manual (PDF)
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File Date: Thu Nov 6 20:31:25 2008
EPA SWMM 4.4 User Manual.
Combined Sewer Overflow Control Manual (PDF)
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File Date: Sun Dec 7 20:32:33 2008
Manual: Combined Sewer Overflow Control
U.S. Environmental Protection Agency
EPA/625/R-93/007
September 1993
This PDF document provides information to assist in selecting and designing control measures for reducing CSOs (combined sewer overflows) from RDII (rainfall derived inflows and infiltration). This document will be useful for municipal public works staff, design engineers, and regulatory agency staff involved in the development and review of facility plans and long-term CSO control programs.
Sewer System Infrastructure Analysis and Rehabilitation Handbook (PDF)
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File Date: Wed Dec 10 20:35:21 2008
Handbook: Sewer System Infrastructure Analysis and Rehabilitation
U.S. Environmental Protection Agency
EPA/625/6-91/030
October 1991
This PDF document provides guidance on the evaluation and rehabilitation of existing sewers. It presents information on typical problems, procedures, and methods of rehabilitation, case study information, budgetary costs, advantages and disadvantages of rehabilitation techniques, and application of these techniques and materials/equipment used in rehabilitation. It also guides the reader in understanding the importance of, and ways for, conducting the sewer system evaluation and identifying the rehabilitation procedure that best suits a particular problem.
How to Delineate a Watershed (PDF)
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File Date: Wed Dec 10 20:16:21 2008
This PDF document describes the steps involved in performing a watershed delineation into separate subbasins.
