Sump pump sizing survey

[Thatguy]

hp of your pump?
nearest big city?
how many consecutive years has it been able to keep up?
how often over how many years hasn't it been able to keep up?

Even five answers would be good, depending on how much the data is scattered.

Thank for your help.

[cacher_chick]

1/3 hp
Milwaukee
5
never

I would speculate that in 99% of basement floods, the problem was never that the the sump pump could not "keep up".
The flood comes after the switch or motor fails because it cycles too frequently.

[Thatguy]

Thanks for your input. As soon as I can find the paperwork on mine I'll have all of two datapoints! For the DC area mine has worked at least since '92.

A reasonable range of sump pump sizes seems to be from 1/6 to 1 hp.
With a range this large, either a single variable speed pump or two pumps, one small and one large, may be the solution to prolong pump life. To prevent the large pump from seizing up from lack of use a little $20 circuit could goose the thing for a minute or so once per week or once per month.

Based on cost/risk/benefit it seems like a sump water level alarm is also a good idea.

I couldn't seem to find any recent patents on sump pump improvements.

I'd think the pump(s) should be able to handle a rainfall event or flood event that returns only every 10 years or 20 years and that info is available for major cities.
100 year returns for Juneau, Alaska is 0.6" and 6.2" for Hilo, Hawaii. This is also a pretty wide range.