To download the following technical documents, check the box of the desired documents below and then click the "Download Selected" button. An e-mail will be sent to you with the download links. These documents are available in Adobe Acrobat 4.0 PDF format.
Flood Studies Work Plan
File Size: 362756 bytes
File Date: Fri Jan 3 14:19:03 2003
This PDF technical document describes, in general terms, the hydrologic work necessary for a flood study.
Flood Studies and Maps
File Size: 1423979 bytes
File Date: Fri Jan 3 14:02:56 2003
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)
File Size: 1318314 bytes
File Date: Wed May 15 14:36:15 2002
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)
File Size: 3593796 bytes
File Date: Wed Apr 10 23:57:18 2002
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)
File Size: 5283414 bytes
File Date: Tue Sep 11 14:16:12 2001
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)
File Size: 14855288 bytes
File Date: Wed Sep 28 02:46:39 2005
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 Delineating Watershed from AutoCAD DXF File (PDF)
File Size: 200864 bytes
File Date: Fri Aug 3 16:39:13 2001
This documentation describes how to use WMS to delineate a watershed from an AutoCAD DXF file. The procedure involves converting the DXF file to TIN first, and then following it up with the conversion of the TIN to DEM data. The DEM data is then processed using WMS commands to generate a watershed.
Download Documentation on Detention Pond Design (PDF)
File Size: 24821 bytes
File Date: Thu Jun 28 17:05:09 2001
This files contains lecture notes from the University of Texas on detention pond design.
Download Documentation on Design Storm Development (PDF)
File Size: 23705 bytes
File Date: Thu Jun 28 17:05:08 2001
This file contains lecture notes from the University of Texas on design storm development.
Download Documentation on Culvert Design (PDF)
File Size: 65599 bytes
File Date: Thu Jun 28 17:05:07 2001
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)
File Size: 10653450 bytes
File Date: Thu Mar 8 15:28:34 2001
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)
File Size: 5533871 bytes
File Date: Thu Jul 6 16:30:05 2000
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 Technical Document about ArcInfo ARCDXF Command (PDF File)
File Size: 19858 bytes
File Date: Tue Mar 25 17:49:58 2003
This document contains technical documentation for the ArcInfo ARCDXF command (used for creating a WMS-readable DXF file from an ArcInfo coverage). If you have an ArcInfo vector coverage, you can convert this ArcInfo data to a DXF file using the following command:
ARCDXF .dxf line_cov point_cov annot_cov
The command above will save a file called .dxf that will contain all the vector data contained in line_cov (a line coverage in ArcInfo), point_cov (a point coverage in ArcInfo), and annot_cov (an annotation coverage in ArcInfo).
Download Technical Document about ArcInfo GRIDASCII Command (PDF File)
File Size: 8808 bytes
File Date: Tue Mar 25 17:50:17 2003
This document contains technical information about the ArcInfo GRIDASCII command (used for creating a WMS-readable ASCII grid file from an ArcInfo grid coverage). If you have an ArcInfo Grid coverage, you can convert this ArcInfo data to an ArcInfo ASCII grid file that can be read into WMS using the following command:
GRIDASCII in_grd grid.asc
The command above will save an ArcInfo ASCII Grid file called grid.asc that contains the data for each cell in in_grd in an ASCII grid file format. The VALUE attribute will be converted to the ASCII grid file format. Most of the time, this VALUE attribute will be elevation, so you will end up with an ASCII elevation grid.
Download Technical Document about ArcInfo UNGENERATETIN Command (PDF File)
File Size: 16025 bytes
File Date: Tue Mar 25 17:56:19 2003
This document contains technical information about the ArcInfo UNGENERATETIN command (used for creating a WMS-readable ASCII net file from an ArcInfo coverage). If you have an ArcInfo TIN, you can convert this ArcInfo TIN to an ArcInfo ASCII NET file that can be read into WMS using the following command:
UNGENERATETIN in_tin tin.asc NET
The command above will save an ArcInfo ASCII TIN file in ArcInfo ASCII NET (Node, Edge, Triangle) format called tin.asc. The ArcInfo TIN is called in_tin in this example.
Download Technical Document about Uncompressing .tar.gz Files Using WinZIP (PDF File)
File Size: 36903 bytes
File Date: Fri Nov 6 02:55:05 1998
This technical document describes how to use WinZIP to uncompress UNIX .tar.gz files. WinZIP can handle UNIX .tar.gz files but it does get confused by the two dots in the filename. This document describes in detail how to uncompress .tar.gz files using WinZIP.
Download Estimation of Green-Ampt Infiltration Parameters (PDF File)
File Size: 14316 bytes
File Date: Wed Mar 22 17:55:53 2000
This document provides estimation of Green-Ampt Infiltration Parameters (SWMM RUNOFF variables SUCT, HYDCON, SMDMAX).
Download TR-20 Proposed Input - Output Specification (PDF File)
File Size: 289189 bytes
File Date: Tue Mar 25 17:55:18 2003
TR-20 has existed for 16 years in draft status, and in the fall of 1997, the newly formed TR-20 work group made the momentous decision to revise, modernize, and finalize the program. This effort will include upgrading the source code language to Fortran 90, changing the philosophy of data input, developing a Windows interface and output post-processor, and adding GIS capability to the program. A converter program will be developed to reformat old data sets so they can be run in the new program version. This document is concerned only with the proposed TR-20 model Input and Output specifications. (No details concerning any part of the TR-20 software system except the TR-20 model input and output specifications are covered.)
Download USDA Engineering Field Handbook Chapter 19 - Hydrology Tools for Wetland Determination (PDF File)
File Size: 259471 bytes
File Date: Tue Mar 25 17:50:07 2003
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)
File Size: 1833381 bytes
File Date: Tue Mar 25 17:55:02 2003
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)
File Size: 32044 bytes
File Date: Tue Mar 25 17:49:59 2003
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)
File Size: 20193 bytes
File Date: Tue Mar 25 17:52:16 2003
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)
File Size: 23255 bytes
File Date: Tue Mar 25 17:54:03 2003
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)
File Size: 13569 bytes
File Date: Tue Mar 25 17:49:57 2003
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)
File Size: 101995 bytes
File Date: Tue Mar 25 17:55:07 2003
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)
File Size: 6892 bytes
File Date: Tue Mar 25 17:55:07 2003
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.
