Posted on: February 15, 2018
Has your community been affected by flooding because of your storm drainage systems?
If so, this isn’t uncommon; in fact, for many communities, urban expansion impacts their aging and undersized storm drainage systems, leading to flooding.
And as you know, flooding brings many undesirable consequences with it such as increased sanitary infiltration/inflow (I/I), which gives rise to basement “back-ups”—and more flooding.
In order to adequately resolve the problems associated with deficient storm handling capability, it’s necessary to obtain a comprehensive understanding of the system behavior and performance.
One method to obtain such an understanding is to develop a mathematical model of your storm system.
There are several advantages to using a mathematical model over the conventional method of long-term flow monitoring coupled with a statistical analysis of rainfall data.
To begin with, it is more economical, time-saving, and accurate.
Also, it provides more flexibility of analysis and can be modified to adjust to changing environmental conditions.
A model can help you develop your management strategies to reduce the impact of flooding while minimizing the resources to do so—or in other words, optimization.
Proper management strategies will ultimately ameliorate flooding impacts such as:
The model can also assist you with planning and design, sewer rehabilitation, and analyzing “What if?” scenarios prior to construction.
Storm sewer models have two main components: hydrologic (rainfall/runoff) and hydraulic (transport/drainage system).
Traditionally, estimating runoff had been relegated to approximating peak discharges based on empirical formulas. However, with the advent of digital computers, more accurate estimates of runoff are obtained by incorporating complex time-dependent rainfall intensity.
The complexity of your storm sewer model should be tailored to data availability and the objective that you wish to obtain. Jones & Henry personnel have extensive experience in developing models using numerous software to meet our clients’ expectations.
One software we use is the EPA’s Storm Water Management Model (SWMM), which is, perhaps, the best-known and most-used-worldwide software for storm and sewer modeling. (Most commercial software available on the market is actually based on the EPA’s SWMM model.)
SWMM has graphical user interfaces that allow ease of data input and verification, thereby reducing the possibility of errors. If desired, tabular input is also available. Likewise, data input can also be accomplished by means of both tabular and graphical interfaces.
Jones & Henry can assist you in your storm water management strategies to achieve the most efficient expenditure of capital resources to improve urban drainage in your community.
Some specific activities we can help you with include:
Have you used the EPA’s Storm Water Management Model (SWMM) in the past? Tell us about your experience.