I am sure this refers to a type of swimming pool called a "piscina desbordante" or "rebosante" in Spanish and an "overflow pool" in English. This idea is that the surface of the water is at the level of the surrounding decking, there is a slight slope, and a catch basin on the low side which collects the overflow, filters it and feeds it back into the pool. It looks very good and cuts down on cleaning; the floating rubbish gets removed naturally.

Here's an explanation in Spanish:
http://www.arquigrafico.com/las-piscinas-desbordantes-o-rebo...

And some information in English:
http://answers.yahoo.com/question/index?qid=20090329015850AA...
http://phoenix.about.com/od/pools/a/poolshapes.htm

Literally it would be "overflow finish", but I can't find this expression in relation to swimming pools, only sinks and baths. Here is an example of "overflow effect", which I think is a reasonable synonym:

"The inner garden with a perfect overflow effect swimming pool is a work of art."
http://travel.yahoo.com/p-hotel-325740-the_oberoi_grand-i

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Note added at 53 mins (2011-09-16 08:38:44 GMT)
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By the way, as you'll see from my first English reference this type of pool produces a "vanishing edge" effect, which looks very smart and is a major reason people go for them. In fact "vanishing edge effect" might even be worth considering as a translation here. However, according to Wikipedia it's not strictly accurate:

"An infinity edge pool (also named negative edge, zero edge, disappearing edge or vanishing edge pool) is a swimming or reflecting pool which produces a visual effect of water extending to the horizon, vanishing, or extending to "infinity". The term also is used to describe (however, incorrectly) perimeter overflow pools (pools that may be on level parcels, wherein the water flows over one or more edges, usually flush with the decking elevation)."
http://en.wikipedia.org/wiki/Infinity_edge_pool

This does, however, give us another alternative: "perimeter overflow".