Stormwater Management Model (SWMM) Information for watershed water quality, hydrology and hydraulics modelers (Note this Blog is not associated with the EPA). You will find Blog Posts and Twitter Embeds on the Subjects of SWMM5, InfoSWMM, InfoSewer, SWMMLive, InfoSWMM SUSTAIN, SWMM4 and SWMM in general.
Starting from the bottom of the manhole you have these regions of computational interest:
1. Manhole Invert to the lowest link invert – the node continuity equation is used with the area of the manhole being the default surface area of a manhole,
2. Lowest Link Invert to the Highest Link Crown Elevation – the node continuity equation is used with surface of the node being normally half of the surface area of the incoming and outgoing links,
3. Highest Manhole Pipe Crown Elevation to Manhole Rim Elevation – the node surcharge algorithm in which the surface area of the manhole is not used and the surcharge depth is iterated until the inflow and the outflows of the node are in balance,
4. The region above the Manhole Rim Elevation which can use one of four options to calculate the depth and/or flow out of or into the manhole:
1. No Surcharge Depth is entered and No Ponding area is used – the excess water into the manhole is lost to the network and shows up as internal outflow in the continuity tables,
2. A Ponding Area is used and the excess flow will pond on the surface of the manhole and later go back down into the conveyance pipes.
3. A Surcharge Depth is used and the depth will continue to be calculated using the node surcharge algorithm in which the surface area of the manhole is not used and the surcharge depth is iterated until the inflow and the outflows of the node are in balance,
4. A Dual Drainage system is simulated and the excess flow of the manhole is simulated in the street gutters or the actual street,
5. You use a 1D/2D linkage between the 1D manhole and 1D links to a 2D Mesh and simulate the flow out and the flow into the manhole using a bottom outlet orifice that switches automatically between weir and orifice flow based on the depth on top of the manhole.
World-Renowned Urban Drainage Modeling Authority Robert Dickinson Joined Innovyze in January, 2008Broomfield, Colorado USA, January 16, 2008/altered 20142008/2014 Robert E. Dickinson, one of the world’s leading experts in wastewater and urban drainage modeling, has joined Innovyze as Product Sector Leader. Dickinson, who comes to the company from CDM now CDMSmith, will be charged with maintaining, enhancing and supporting Innovyze's flagship SWMM5-based product line (InfoSWMM and H2OMAP SWMM as well as the GIS based InfoSewer and H2OMap Sewer), which are some of the industry’s leading wastewater and urban drainage systems design and modeling software. He will also be responsible for coordinating vital collaborative research and technology transfer with key universities and government organizations as well as developing business strategies that advance Innovye’s overall growth objectives in wastewater and stormwater systems management and heighten its initiatives in both U.S. and i…
Engine Error NumberDescription ERROR 101: memory allocation error. ERROR 103: cannot solve KW equations for Link ERROR 105: cannot open ODE solver. ERROR 107: cannot compute a valid time step. ERROR 108: ambiguous outlet ID name for Subcatchment
These warning and error messages were added in SWMM 22.214.171.124 to 5.0.016 to trap questionable raingage, link and node data. Correcting these errors does make a better model . The list shown below has the major new warnings and errors and help on interpreting the messages. WARNING01: wet weather time step reduced to recording interval for RainGage Explanation: The user selected hydrology time step is automatically reduced by the engine to match the rain gage interval. The smallest rainfall interval among all of the gages will be used during the simulation. WARNING 02: maximum depth increased for Node Explanation: The rim elevation of a node has to be at least equal to the crown elevation of the highest connecting link to the node. The maximum depth of the node is increased to match the highest crown elevation. WARNING03: negative offset ignored forLink Explanation:Negative Offsets are set to offsets of 0.0 WARNING 04: minimum elevation drop used forConduit Explanation: If the elevation acro…