Things that Happened Before You were Born (The earth and SWMM were created) a story by Dr. Larry A. Roesner, Ph.D.,P.E.

based (loosely*) on biblical quotes and his own bigger than life experiences *Actually very loosely

The earth and SWMM parallels In the beginning, there was the Rational Method

Q peak = C·I · A t 3 t 2 t 1

Time of concentration, Σ

t

The earth and SWMM parallels And darkness covered the drainage world because of the limited applicability of the Rational Method

The earth and SWMM parallels Then forward looking engineers said “let there be light” And so, they created more rational models  SCS TR20 and TR55  HEC-1,2,3,4,5,6, and RAS  SWMM

The earth and SWMM parallels   SCS Method accounts for initial soil moisture and time varying

C

Runoff hydrographs can be computed Increasing Imperviousness Runoff

The earth and SWMM parallels    HEC model produces runoff hydrograph from rainfall hyetograph using unit hydrograph technique ( Who knows the Schneider coefficient for a 30% pervious urban area?

Hydrologic routing produces channel flows Hec 2 computes steady state backwater through maximum discharge profile )

The earth and SWMM parallels    SWMM was to be the mother of all models It would trace runoff from its point of origin, through the stormwater system to and through the receiving waters, computing flows and water levels It would trace wet weather pollution from its point of origin to its final fate in the receiving waters

Concept of SWMM Rainfall hyetograph Transport System Data Point Source Loads Q (t) RUNOFF Inlets Q (t) C(t) EXTRAN Q (t) Watershed Data TRANSPORT Transport System Data Outfalls RECEIVE Q (t) C(t) Receiving Water System Data Q (t), C(t) in Receiving Water

The earth and SWMM parallels And so it was, and (most) Civil Engineers saw the models and they were good.

And so they rested, for 30yrs!!?

SWMM Runoff Module

R

f(t)

S Q (t) I

f(t)

S

SWMM Extran Module

INTRODUCTION TO SWMM AND MIKE SWMM

CE 580 Analysis of Urban Water Systems Session 10 – Sept 25, 2000

SWMM Computer Program Layout

Interrelationship of the SWMM Blocks

SWMM Schematic

MIKE SWMM Demonstration

This presentation is an embellishment of the road culvert example contained in the Mike SWMM documentation. In order to see the results of road overtopping, the weirs at nodes 110 and 60 have been changed to box conduits. Three simuations were performed: o The "existing" condition: File name Exam11e.dat

- culvert 110 diameter = 1.0 ft - culvert 60 diameter = 3.0 ft o The "existing" condition: File name Exam11p1.dat

- culvert 110 diameter = 2.0 ft - culvert 60 diameter = 3.5 ft o The "existing" condition: File name Exam11p2.dat

- culvert 110 diameter = 4.0 ft - culvert 60 diameter = 5.0 ft The first simulation shows severe overtopping of the road at both location, with prolonged backwater at junction 110. The second simulation shows much improvement, and the third simulation shows the problem fixed except for a small 15 minute overtopping of the the road at junction 110.

Modifications by LAR 12/2/98

Camp Dresser & McKee

Danish Hydraulic Institute

Danish Hydraulic Institute - a Consulting and Research Organization  Objectives:  to develop and apply advanced methods and technologies 

within hydraulic and hydrological engineering

  to provide specialised consulting services to contribute to the technological development through 

international research collaboration and through



transfer of know-how and technology

MIKE SWMM

MIKE 11

 1-D modeling system for rivers and channels  HD, AD, WQ, ST, FF, GIS  more than 400 users world-wide

MIKE 21  a modelling system for estuaries, coastal waters and seas  more than one hundred users in 35 countries

MIKE SHE    an integrated hydrological modeling system 3-D Groundwater movement, unsaturated zone, Solute transport, dynamic link to MIKE 11 some 50 users in 10 countries

MIKE BASIN   Water Master Planning   use of available water resources planning for future water developments GIS  defining the network   evaluating results integrated analysis with spatial data

LITPACK  an integrated modelling system for Littoral Processes And Coastline Kinetics  more than 60 users in 20 countries

MIKE SWMM Demonstration

Top of Overbank Culvert Top of Bank

Road Elev.

Junction 110 Road Culvert

Road Elev.

Junction 60 Road Culvert

Road Elev.

Junction 110 Road Culvert

Road Elev.

Junction 110 Road Culvert

Road Elev.

Junction 110 Road Culvert

Road Elev.

Junction 110 Road Culvert

Road Elev.

Junction 60 Road Culvert