From the context ("attraverso boschi") it seems very likely that it does not mean an artficial waterway, but one that the spring water has carved for itself.
Brooks are often fed by spring water and a quick internet search shows that this may be an apt choice for your context.

see
http://en.wikipedia.org/wiki/Stream
Brook A stream smaller than a creek, especially one that is fed by a spring or seep. It is usually small and easily forded. A brook is characterised by its shallowness and its bed being composed primarily of rocks.

brook - Definition of brook - Online Dictionary from Datasegment.com
onlinedictionary.datasegment.com/word/brook
Definition of brook in the Online Dictionary. ... fr. the root of E. break, so as that it signifies water breaking through the earth, a spring or brook, as well as a marsh.

Sit on Peace Island surrounded by our spring fed mountain brook ...
www.tripadvisor.com › ... › Denmark › Denmark Accommodations‎
Nurture Through Nature Eco-cabin Rentals and Retreats, Denmark Picture: Sit on Peace Island surrounded by our spring fed mountain brook. - Check out ...

Diamond Brook - Glen Rock
www.glenrocknj.net/environment/pdf/DiamondBrookBrochure.pdf‎
The brook is spring-fed with the headwaters located just north of the Glen Rock border in Ridgewood near the Orchard School. The Diamond Brook flows past ...

trout pics - Saltwater Fishing Discussion Board Including Inshore ...
www.noreast.com › Discussion Boards › Freshwater Forum‎
Dec 19, 2005 - ... conny, the conny is fed by spring water and that water stays cool enough to ... Clear and cool brooks trickling through shady woods has been ...



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Note added at 3 hrs (2013-10-04 18:51:02 GMT)
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p.s. broks can also be artificial/man made

see
A neighborhood girl frolics in an artificial brook, thanks to a fire ...
pcullinan.smugmug.com/Ridgewood-NY.../215290978_CDbgbtg‎
A neighborhood girl frolics in an artificial brook, thanks to a fire hydrant. She is set off by a chance halo created by an effect of reflected light.

WATER FEATURES: MANMADE BROOK - Zoomshare
www.queensyard.zoomshare.com/album/.../images/.../:album‎
WATER FEATURES: MANMADE BROOK. PRINTS. Prints. Photo Gifts. Photo Stationery. All Products. Close. Image 10 of 10. Zoomshare · Back to Site ...