Use the results of a rainfall simulation to optimize and refine a pond’s design.
Tutorial resources
These downloadable resources will be used to complete this tutorial:
Transcript
00:03
the pond currently has an estimate for its volume,
00:06
which has been calculated using the quick storage estimate
00:10
now that the inlets,
00:11
outlets and overflows have been defined.
00:14
It is time to accurately size the pond using dynamic simulation
00:19
with a model open in the ribbon analysis tab criteria,
00:24
panel click analysis criteria.
00:28
In the analysis criteria dialog,
00:30
make sure that only the box next to srp wizard
00:33
F S R is checked so that there are 18 storms
00:38
Set the output interval to two minutes.
00:42
The time step drop down is set to default but for this example,
00:45
change it to shortest to give the model the best chance of producing stable results.
00:51
When running simulations,
00:52
you must strike a balance between getting accurate results
00:56
and how long it takes to get them.
00:59
Complex models require complex hydraulic calculations,
01:02
so setting the time step two shortest will
01:05
make for a longer but more stable simulation,
01:09
click OK.
01:11
In the analysis panel click validate
01:14
in this example. The validate dialogue shows no errors.
01:19
If there were any, for example, a pipe or orifice missing a crucial measurement.
01:24
You would double click each listing to see what caused it
01:27
and resolve each. one
01:29
click OK to close the dialog and then save your progress
01:34
in the analysis panel, click go to run the simulation.
01:39
Once it is finished,
01:40
the storm water controls summary displays the results
01:43
for 1 30 year summer storm event.
01:47
It includes details like the ponds total discharge volume and the percentage
01:51
of the pond that was still available to fill during the storm
01:55
Click critical storm to see the results of the most severe weather event
01:60
in this case a 360 minute winter storm.
02:04
You can also enable all storms to see
02:07
how the model fared during different rainfall events.
02:09
With the critical storm highlighted.
02:12
The critical storm lists a percentage available of seven
02:16
which indicates the pond is slightly oversized.
02:19
But keep in mind that this pond was designed using rough estimates.
02:24
Close the summary and save your progress
02:28
to make the pond smaller
02:29
in the results. Tab summaries panel select stormwater controls
02:35
again, click critical storm and make sure all storms is toggled on.
02:41
In order to resize the pond,
02:43
you must consider its maximum resident volume during the critical storm
02:47
which is 792 m3.
02:50
In this example,
02:52
this measurement provides a guideline for re
02:54
sizing the pond as its maximum depth and
02:57
outflow or discharge are both less than the
02:60
values established in the original design criteria.
03:04
Close the dialog
03:06
double click the pond icon to view its properties and open the sizing calculator,
03:11
Enter a new volume of 795, slightly more than the 792 from the simulation results.
03:18
And click OK
03:20
click OK again in the pond dialogue and observe how
03:23
the ponds size decreases slightly in the plan view,
03:28
check that the inlet and outlet are still within the boundary of the pond.
03:32
Save your progress.
03:35
Return to the analysis tab and select validate again.
03:39
In this example. There are no errors.
03:42
So click OK
03:44
click go again to rerun the simulation with the new volume
03:51
in the storm water controls summary, click critical storm,
03:54
then toggle on all storms.
03:57
This time only 1% of the pond was available during the critical storm.
04:02
The maximum depth and discharge are also closer to but do
04:06
not exceed the measurements established in the original design criteria,
04:10
meaning upon size
04:11
is now properly optimized.
00:03
the pond currently has an estimate for its volume,
00:06
which has been calculated using the quick storage estimate
00:10
now that the inlets,
00:11
outlets and overflows have been defined.
00:14
It is time to accurately size the pond using dynamic simulation
00:19
with a model open in the ribbon analysis tab criteria,
00:24
panel click analysis criteria.
00:28
In the analysis criteria dialog,
00:30
make sure that only the box next to srp wizard
00:33
F S R is checked so that there are 18 storms
00:38
Set the output interval to two minutes.
00:42
The time step drop down is set to default but for this example,
00:45
change it to shortest to give the model the best chance of producing stable results.
00:51
When running simulations,
00:52
you must strike a balance between getting accurate results
00:56
and how long it takes to get them.
00:59
Complex models require complex hydraulic calculations,
01:02
so setting the time step two shortest will
01:05
make for a longer but more stable simulation,
01:09
click OK.
01:11
In the analysis panel click validate
01:14
in this example. The validate dialogue shows no errors.
01:19
If there were any, for example, a pipe or orifice missing a crucial measurement.
01:24
You would double click each listing to see what caused it
01:27
and resolve each. one
01:29
click OK to close the dialog and then save your progress
01:34
in the analysis panel, click go to run the simulation.
01:39
Once it is finished,
01:40
the storm water controls summary displays the results
01:43
for 1 30 year summer storm event.
01:47
It includes details like the ponds total discharge volume and the percentage
01:51
of the pond that was still available to fill during the storm
01:55
Click critical storm to see the results of the most severe weather event
01:60
in this case a 360 minute winter storm.
02:04
You can also enable all storms to see
02:07
how the model fared during different rainfall events.
02:09
With the critical storm highlighted.
02:12
The critical storm lists a percentage available of seven
02:16
which indicates the pond is slightly oversized.
02:19
But keep in mind that this pond was designed using rough estimates.
02:24
Close the summary and save your progress
02:28
to make the pond smaller
02:29
in the results. Tab summaries panel select stormwater controls
02:35
again, click critical storm and make sure all storms is toggled on.
02:41
In order to resize the pond,
02:43
you must consider its maximum resident volume during the critical storm
02:47
which is 792 m3.
02:50
In this example,
02:52
this measurement provides a guideline for re
02:54
sizing the pond as its maximum depth and
02:57
outflow or discharge are both less than the
02:60
values established in the original design criteria.
03:04
Close the dialog
03:06
double click the pond icon to view its properties and open the sizing calculator,
03:11
Enter a new volume of 795, slightly more than the 792 from the simulation results.
03:18
And click OK
03:20
click OK again in the pond dialogue and observe how
03:23
the ponds size decreases slightly in the plan view,
03:28
check that the inlet and outlet are still within the boundary of the pond.
03:32
Save your progress.
03:35
Return to the analysis tab and select validate again.
03:39
In this example. There are no errors.
03:42
So click OK
03:44
click go again to rerun the simulation with the new volume
03:51
in the storm water controls summary, click critical storm,
03:54
then toggle on all storms.
03:57
This time only 1% of the pond was available during the critical storm.
04:02
The maximum depth and discharge are also closer to but do
04:06
not exceed the measurements established in the original design criteria,
04:10
meaning upon size
04:11
is now properly optimized.
After a pond has an estimated volume and the inlets, outlets, and overflows have been defined, it is time to accurately size the pond using dynamic simulation.
When running simulations, you must strike a balance between getting accurate results and how long it takes to get them. Complex models require complex hydraulic calculations, so setting the Time Step to Shortest will make for a longer but more stable simulation.
If there were any errors—for example, a pipe or orifice missing a crucial measurement—you would double-click each listing to see what caused it and resolve each one.
Once it is finished, the Stormwater Controls Summary displays the results for one 30-year summer storm event. It includes details like the pond’s total discharge volume and the percentage of the pond that was still available to fill during the storm.
The critical storm lists a Percentage Available (%) of 7, which indicates the pond is slightly oversized, but keep in mind that this pond was designed using rough estimates.
This time, only 1 percent of the pond was available during the critical storm. The maximum depth and discharge are also closer to—but do not exceed—the measurements established in the original design criteria, meaning the pond’s size is now properly optimized.
