Water Modeling Hub: Expert Insights on SWMM5, ICM & InfoSWMM: 12/01/2009

Thursday, December 24, 2009

15 GPM

From the South Florida Watershed Journal

Fifteen gallons per minute

Alternative measurement units:

0.03 cubic feet per second
508 barrels per day (using 42.5 gallon barrels)
24 acre feet per year
7.9 million gallons per year
12 Olympic swimming pools per year

Saturday, December 12, 2009

Weather Underground Data and SWMM 5

Weather Underground is a site that provides excellent local weather information in the form of graphs, tables and csv files. You can use the data very easily in SWMM 5 by copying from Excel to a time series in SWMM 5.

The data imported from the csv file to Excel and after the text to columns tool is used looks like this in Excel. The data is now ready to be imported into SWMM 5 after the time column is adjusted to fall on even 5 minute intervals. In Excel you can use the formula @ROUND((B2)/"0:05:00",0)*"0:05:00" to round all of the time values to 5 minutes. If you do not do this step then you will have problems in SWMM 5 due to the rainfall interval not being equal to the defined raingage interval.

Open up and make a new time series in SWMM 5 and then copy and paste the date, rounded time column and rainfall column into the SWMM 5 time series.

InfoSWMM and H2oMAP SWMM Release Notes

Sediment Modeling

SCS Rainfall Distributions

Sunday, December 6, 2009

Node Convergence in SWMM 5

The solution is iterative but each iteration is dependent on the CFL or explicit time step. The time step we select is based on the CFL condition but instead of just using the explicit solution we iterate until the node depths are converged or a maximum of 4 iterations is reached.

The solution of node depths and link flows in SWMM 5 is an iterative process but the number of iterations for the flows and links depends on how fast the node depth converges. The node continuity equation is ALWAYS solved at each iteration for each node but depending on whether both the link upstream and downstream node depths have converged the the number of iterations for a link may be between 2 and 4. The minimum number of iterations for a link is 2.

Figure 1. Iterations in SWMM 5

SWMM456.COM

SWMM456.COM (previously known as SWMM5.NET) is a mini-blog that provides short and concise articles about various topics related to Stormwater Management Model (SWMM). Each post on the blog is no more than 150-200 words (about 1300 characters) in length and aims to deliver instant information, opinion, or introduction on a specific topic related to SWMM. The blog covers a wide range of topics, including tips and tricks for using SWMM, case studies, software updates, and news related to the field of stormwater management. The goal of the blog is to provide useful and relevant information to SWMM users and professionals in the stormwater management industry in a quick and easy-to-digest format.

Information

You can see recent Posts in the Recent Post Section, Top Labels, Older Alphabetical Labels and Dated Archives. You can also search for Tags in the Google Search Box or the Custom Search Box. The above Tabs in the Menu are those sites and blogs that I think can help you. Pleasse send any further questions to robert.dickinson@gmail.com or robert.dickinson@innovyze.com if you have further questions or ideas. If you are a student and you want a general introduction to SWMM 5 please visit Wikipedia or the EPA Tab. Thanks for visiting!

Best New Blog: http://blog.innovyze.com/2014/11/30/advanced-calibration-graphs-and-advanced-reference-graphical-comparisons-in-infoswmm-13/ The Current InfoSWMM Version is InfoSWMM v14 which is based on EPA SWMM 5.1.010 You can read about SWMM5 on Wikipedia and InfoSWMM vs SWMM 5 on this blog post. An advantage of updating to the newer version of Info/Map/SWMM/Sewer is a newly designed help file with many more FAQ’s and the User Guide as part of the help file. You can use the Google translate tool at the top of the right hand side to translate any and all blog posts.