I wanted a simple water level to check the sump water level and
comapare to street elevation. couldnt see one from the other.

unplugged sump pump

bought a ball valve that screwed on the garden hose at the outside
outlet.

opened ball valve, turned on water let it run till the sump had a good
bit of water in it, garden hose weighted down a bottom with a brick.

turned off ball valve

turned off water faucet

this left garden hose filled with water

unscrewed garden hose with ball valve from faucet.

walked 90 feet to street

lifited hose hanging down above my head. opened ball valve

lowered hose quickly till water in hose just lapped at top of ball
valve.

duplicated several times there was 28 inch drop from sump water level
to street

decided more than enough drop for sump overflow line to street.
although for unknown reasons the home buyer decided he didnt want the
drain.

during home sale process we had 100 year flood and a foot of water in
basement after power failure.....

the buyers home had 6 feet in the living room, basement full 9 feet of
water so maybe he thought it minor inconvenience.

whenever possible sumps should have a gravity drain or at least
overflow