SWMM5, InfoSWMM

How Dry Weather Flow is Used in InfoSWMM at a Node

Note: How Dry Weather Flow is Used in InfoSWMM at a Node

There are four components to the Dry Weather Flow (DWF) in InfoSWMM:

1. The mean flow in user units at the node,

2. The DWF Allocation Code – if you are using the DWF Allocator

3. The Pattern for Weekday, Weekend etc for the mean flow.

The data is entered or entered for you in the Node Inflow Icon or the Operations Tab of the Attribute Browser

Node Inflow Icon and Associated Data

Operation Tab Patterns

You can also make global changes to your DWF using the Node DWF DB Table Under Extended Element Modeling Data

SWMM5 Weir Rules, Head Calculations and Weir HGL Plots

Note: SWMM5 Weir Rules and Head Calculations

This note attempts to explain both how the head upstream and the head downstream of a weir in SWMM 5 is calculated compared to the weir crest elevation and also to explain how the weir is presented in the HGL plot of SWMm 5. There has been confusion in the past concering how the weir is shown compared to the actual weir calculations. The node head is calculated obviously at both ends of the weir but the head over the weir is always based on H1-Crest or H2-Crest (Figure 1) and hence the weir should look flat – to the weir the downstream head is important but NOT the downstream node invert so the weir really is flat and should look flat in the HGL Profile across the weir (Figure 2). The crest elevation is always relative to the upstream node invert elevation NOT the downstream node invert elevaation

Figure 1. How the Head across a Weir is calculated in SWMM 5

Figure 2. HGL Profile across a Weir in SWMM 5.0.022. The black line should be shown flat.

World Wide Visitor Coverage of WWW.SWMM2000.COM

Note: For the 1^st time in 4 years we have had a visitor from Central Asia. This now means we have had visitors from all Google defined Geographic Regions on Earth even though we still have not had visitors from every country at www.swmm2000.com The statistics below exclude the 58 percent visitors from North America but overall we have had:

1. 40,190 Visitors

2. 22 Continental Regions

3. 157 Countries

4. 5951 Cities

5. 100,180 Pageviews

6. 86 Languages

Time Step Approximation based on Link Lengths

Note: A rough approximation of the time step you need for an InfoSWMM or H2OMAP SWMM model can be found by finding the mean link length using the field statistics tool for the length in the Conduit DB Table and then estimating the time step from the mean length, mean full depth velocity and mean full depth wave celerity.

The time step actually used during the simulation is related to this velocity and the safety adjustment factor. The larger the safety adjustment factor the larger the mean time step listed in the Routing Time Step Suggestion.

Stream Names in the USA

Stream Names in the USA from http://derekwatkins.wordpress.com/2011/07/25/generic-stream-terms/

Generic place names (or toponyms) such as Cumberland Gap or Mount Rainier provide general categorical descriptions of a geographic feature, in contrast to specific toponyms, which provide a unique identifier: Lake Huron. This map taps into the place names contained in the USGS National Hydrography Dataset to show how the generic names of streams vary across the lower 48. Creeksand rivers are symbolized in gray due to their ubiquity (although the etymology behind the American use of creek is interesting), while bright colors symbolize other popular toponyms.

Lite-Brite aesthetic notwithstanding, I like this map because it illustrates the range of cultural and environmental factors that affect how we label and interact with the world. Lime green bayous follow historical French settlement patterns along the Gulf Coast and up Louisiana streams. The distribution of the Dutch-derived term kill (dark blue) in New York echoes the colonial settlement of “New Netherland” (as well as furnishing half of a specific toponym to the Catskill Mountains). Similarly, the spanish-derived terms rio, arroyo, and cañada (orange hues) trace the early advances of conquistadors into present-day northern New Mexico, an area that still retains some unique cultural traits. Washes in the southwest reflect the intermittent rainfall of the region, while streams named swamps (desaturated green) along the Atlantic seaboard highlight where the coastal plain meets the Appalachian Piedmont at the fall line.