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Hydraulics and Hydrology
Tools and Models - Sites
SITES
Earthen/Vegetated Auxiliary Spillway Erosion Prediction for Dams
(version 2005.1.4 as of July 2009)
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The Natural Resources Conservation Service, the Agricultural
Research Service, and Kansas State University used government funds
to develop the Water Resources Site Analysis Program (SITES)
computer program. It may be downloaded for use and copying at no
additional expense or license requirements. |
History
SITES User Guide
Erosion Technology
Program Purpose
Design Guidance
Contact NRCS
Features
Example Data
Downloads
Integrated Development
Training Materials
Version 2005.1.4
Environment (IDE)
History
The SITES software is a descendent of the DAMS2 program, a full-featured rainfall-runoff
routing program developed for watershed dam design and analysis. In developing
the SITES software, DAMS2 was recoded and the auxiliary (emergency) spillway
analysis portion of the program was expanded to include technology developed for
spillway performance evaluation through the joint efforts of the Agricultural
Research Service (ARS) and the NRCS. The Integrated Development Environment
(IDE) for the SITES software was developed cooperatively by NRCS, ARS, and
Kansas State University. The SITES computer program can be used for both TR-60
watershed dams and 378 CO-01 dams.
Program Purpose
SITES models erosion in earthen and vegetated auxiliary spillways of dams. The
three-phase erosion model that SITES uses was jointly developed by the Agricultural
Research Service (ARS) and the NRCS.
1)
Phase one of the erosion or failure process is failure of the vegetal cover and
the development of concentrated flow.
2)
Phase two is downward erosion in the area of concentrated flow, resulting in
headcut formation.
3)
Phase three is downward and upstream movement of the headcut, potentially
breaching the spillway.
Each phase is described by a set of threshold-rate relationships based on the
process mechanics. A headcut erodibility index (Kh) describes the resistance of
the exposed geologic materials to erosive attack during the third phase of the
process. Aids for estimating this index are included in help screens and in
supporting materials discussed below.
Features
The Sites software has great flexibility in developing the auxiliary spillway rating
and evaluating exit channel stability. SITES accepts vegetal retardance potential for
flow resistance input as well as Manning's n, and flow resistance can vary from reach
to reach in the spillway. SITES develops a spillway rating for subcritical exit channel
flow. For both supercritical and subcritical flows, SITES evaluates exit channel
stability using the allowable tractive stress approach.
When applied in design, the earth spillway erosion model incorporated into SITES is
normally used to evaluate the potential for spillway breach under a freeboard hydrograph
having at least 24 hours rainfall duration. Evaluation of the potential for extending
the model for use in predicting breach rates is presently underway.
SITES Integrated Development Environment (IDE)
NRCS, ARS, and Kansas State University cooperatively developed the SITES IDE. SITES software
(11.5 Mb) includes the IDE with help for input and output screens. The interface handles sites
in series, but primarily analyzes the most downstream structure. SITES runs in Windows
98SE/2000/ NT/XP/Vista operating systems (version 2000 or later recommended). Minimum recommend
RAM is 32 Mb.
The IDE user interface guides the user through data input screens and output interpretation.
Output includes a customizable summary table and graphical output showing hydrologic, structural,
and hydraulic parameters. The IDE handles complex watersheds with upstream structures, sub-watersheds,
and channel reaches through a watershed schematic screen.
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SITES User Guide |
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The SITES User Guide (34.8 Mb) package contains SITES Water Resource Site Analysis Computer Program
User’s Guide (210-728.5) documenting the capabilities and I/O requirements. Appendix A is a Quick
Start guide for beginning users. The User's Guide describes use of the software through the integrated
development environment as well as providing information to allow advanced users to access extended
capabilities of the computational routine.
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Design Guidance |
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The design guidance package (3.7 Mb) contains Chapters 50, 51, and 52 of NRCS NEH 628, TR-60,
and NHCP-378. Chapters 50, 51, and 52 of NRCS NEH-628 contain auxiliary spillway layout and
design guidance, details of the auxiliary spillway performance model, and procedures for
estimating the headcut erodibility index, respectively. TR-60 and NHCP-378 describe NRCS design
criteria and are essential references for development of input data for application of SITES. A
spreadsheet is available to assist in calculating the Headcut Erodibility Index, khcalc.xls,
(also in the design guidance package). Instructions for its use are contained within the
spreadsheet itself and on pages 31-33 of NEH-628 Chapter 52 of the design guidance package.
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Example Data |
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The example data package (15 Kb) includes example data for testing and becoming familiar with SITES.
Data sets with the D2C extension may be imported into the IDE. Data sets with the DAT extension
illustrate the extended capabilities of the computational routine for advanced users. These sample
data sets are discussed in Appendix C of the SITES Water Resource Site Analysis Computer Program
User’s Guide. The data sets were developed to illustrate program features only, and do not represent
any real sites or conditions.
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Training Materials |
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The training and tutorial package (20.9 Mb) contains Power Point® presentations and notes that may be used
for training or as a self-study tutorial. These presentations were originally developed to train NRCS
engineers and geologists in the use of the SITES software. A background in hydraulics and erosion mechanics
is assumed. This package was developed for earlier versions of SITES and discussions may not reflect all
capabilities of SITES 2005.
More Spillway Erosion Technology Information
The user is responsible to understand the complex spillway erosion processes, input variables required
by the model, and the applicability of the model to design conditions. Publications documenting the
underlying spillway erosion technology are available through the USDA ARS Hydraulic Engineering Research
Unit in Stillwater, OK.
Contact NRCS
Karl Visser (ph: 817-509-3763 email:
Karl.Visser@ftw.usda.gov)
Helen Fox Moody (301-504-3948 email:
helen.moody@wdc.usda.gov)
Download List
SITES 2005 (version 2005.1.4) (11 Mb)
Sites 2005 Users Guide
Dam and Spillway Design Guidance Package (4 Mb)
Example Data (15 Kb)
Training/Tutorial Materials (21 Mb)
The use of trade names does not constitute endorsement by the
developers or by the USDA. |
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