Pumps in EXTRAN

I am using MikeSWMM 2002, and I am having a problem modeling a pump
station. There are two pumps involved: one pumps to a lagoon, while the
other pumps to the wastewater treatment plant. During dry weather flow,
everything gets pumped to the plant, and during wet weather flow,
everything gets pumped to the lagoon. I want the pump that goes to the
plant to turn off when the depth in the wet well is equal to 5 feet
(corresponding to base flow conditions), at which point the pump that
goes to the lagoon turns on. Then when the depth in the wet well gets
back down to 5 feet, the pump that goes to the lagoon turns off, and the
pump that goes to the plant turns back on. Both pumps are modeled as
variable speed pumps. I've played around with the on/off depths, but I
can't seem to get my model to produce the desired results. Please let
me know if you've modeled a similar situation. Thanks.

Jennifer Matik
jmatik@hntb.com

You could do this with Type 4 pumps. Type 4 pumps are basically rating
curves where you enter up to 10 pairs of depth/flow values. You could
model each of your pumps to do what you need. Note that you must enter
IPRATE=1 on the BB line to be able to use more than 3 pairs of values
for the rating curves.

Reinhard Sprenger
rsprenger@UMAGROUP.COM