Basic Environmental Technology Water Supply Waste Management and
Basic Environmental Technology Water Supply, Waste Management, and Pollution Control SIXTH EDITION CHAPTER 9 Stormwater Management Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -1 The rational formula is used to estimate the peak or maximum rate of surface runoff due to a particular storm in a specific drainage basin. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
TABLE 9 -1 Typical Runoff Coefficients Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -2 The time of concentration for a drainage basin includes overland flow time and channel flow time. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -3 A chart like this may be used to estimate the overland flow time when the average travel distance, slope, and runoff coefficient are known. (Courtesy of Federal Aviation Administration. ) Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -4 Average velocities for estimating travel time for shallow concentrated flow. (From “Urban Hydrology for Small Watersheds, ” with permission from the Soil Conservation Service, U. S. Department of Agriculture. ) Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -5 A rough approximation of channel flow time may be obtained with this nomograph using a straight edge. For example, the time of travel in a channel that drops 4 m in elevation over a distance of 500 m is about 15 min. A more accurate estimate can be obtained using Manning’s formula. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
TABLE 9 -2 Typical SCS Runoff Curve Numbers Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -6 A selection of SCS rainfall–runoff relationships for several CN values. (From “A Method for Estimating Volume and Rate of Runoff in Small Watersheds, ” with permission of the Soil Conservation Service, U. S. Department of Agriculture. ) Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -7 Unit peak discharge in csm/ in. of runoff versus time of concentration for a 24 -h storm duration. (From “Urban Hydrology for Small Watersheds, ” with permission from the Soil Conservation Service, U. S. Department of Agriculture. ) Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -8 Curve A shows a storm hydrograph for the original or predevelopment conditions; curve B shows a postdevelopment hydrograph for the same area. Land development or urbanization causes the volume and rate of stormwater runoff to increase. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -9 Proper location of stormwater inlets prevents stormwater runoff from flooding a street intersection. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -10 There are several different types of stormwater inlets, including (a) the curb inlet, (b) the gutter inlet, and (c) the combined inlet. Curb opening inlets are undesirable due to the possibility that small objects or animals can fall into the basin. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -11 A section view of a typical stormwater inlet basin. Catch basins that trap grit, leaves, and debris are not commonly used in new storm sewer systems. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -12 Illustration for Example 9 -7. Plan view of drainage area. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -13 Section view of a stormwater detention pond. The outlet structure acts as a bottleneck, restraining the rate of discharge from the pond. The pond or basin is usually empty of water during dry weather, except perhaps for a small stream Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -14 The outlet structure for a detention basin can be hydraulically designed to reduce peak discharge flows from a range of storm magnitudes or frequencies. Multiple-outlet openings or specially designed proportional weirs can be used for this purpose. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -15 Typical inflow and outflow hydrographs for a stormwater detention basin. The basin and outlet structure reduce the peak rate of runoff from a developed site. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -16 The relationship between flow factor and storage factor offers a simplified procedure for stormwater detention calculations. (From A. Pagan, “Flow factor line used in storage calculations, ” Irrigation Journal, 1980, with permission of the American Society of Civil Engineers. ) Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -17 A triangular hydrograph provides a reasonable estimate of total rainfall volume. The peak flow, or height of the triangle, can be computed using the rational formula. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -18 A plan view of the Pennswood Village stormwater system. (Courtesy of Princeton Hydro, LCC, and Wells Appel Land Strategies, Lambertville, New Jersey. Used with permission. ) Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -19 The 100 -year floodplain or flood hazard area includes the floodway and the flood fringe areas. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -20 flow channel. Urban development in a floodplain causes an increase in flood elevations due to the constricted Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -21 A typical flood hazard area map, which shows a plan view of the floodway and flood hazard area. (Courtesy of Division of Water Resources, New Jersey Department of Environmental Protection. ) Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -22 Example of a vortex valve. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -23 Example of a Hydrovex™ Fluidsep vortex separator. Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -24 A typical Hydro. CAD routing diagram showing subcatchments, reaches, ponds, and links. (Screen image courtesy of Hydro. CAD Software Solutions LLC. ) Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
FIGURE 9 -25 A typical Hydro. CAD hydrograph. (Screen image courtesy of Hydro. CAD Software Solutions LLC. ) Basic Environmental Technology, Sixth Edition Jerry A. Nathanson | Richard A. Schneider Copyright © 2015 by Pearson Education, Inc. All Rights Reserved
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