Basement Tanking or Sump Pump

[nam]

Hi All,
Anyone here have any experience of basements. I have a basement not dug out which was recently flooded there is currently no tanking or sump pump installed

what is most cost effective to prevent the flooding a sump pump or Tanking

 

[nam]

Let me guess, East London? I have 2 colleagues who spent the weekend bailing out their vehicles (parked in underground car parks).

Correct 4-5 inches came in from the rear of the property where the current drainage was not adequate. I had 2 drain snake flood bags which could not cope water was coming through the walls in the corners.

I hired for 7 days from HSS industrial dehumidifer and 2 dryers and has made a massive difference already though i am aware there is a another storm expected on Thursday.

As the basement is only for Storage with a bare concrete floor i need to solve 2 issues

1) Prevent the water getting in from outside which i believe is due to the small Sump drain outiside not being adequate
2) Improve the current musty damp smell


The photo shows the low-level drainage which could not cope. This is what i am hoping can be dug-out for a pump and cavity drain. Any ideas on expected costs ?

 

[nam]

Thank you all for your advice i got a specialist in who i explained the issue to they recommended a low level puddle pump which would require no digging. There quote seems to be too expensive for me (Labour) for half a day if that of work

i would like to buy a low level puddle pump myself and get a tradesman to fit or attempt myself if i can work out which UPVC pipe and non return value i need


This a diagram of what i would like to get done

Any advice here ?