Water in Crawlspace

[Joel NA]

There's water in the crawlspace of a prospective investment property at which we're looking.

It looks like the heavy clay soils are holding the water under the house and it can't "leak" back out through the crawl foundation and footers (which look surprisingly good). BTW the joists look good but a lot of the subflooring has been ruined by the moisture.

I was thinking of a plan, if we can "buy right", that would entail pumping out the water, digging an exterior perimeter drain and installing a sump. Obviously we'd check plumbing and gutters.

Any suggestions on logical steps if we end up buying this place?