67 



northward from Riiicon to Veuto on the Almeiidares River in the northern 

 watershed. Aside from the "ojos de agna" along the edge of the cienegas 

 skirting the southern coast there are two notable places where imder- 

 gronnd rivers find an exit. The one at Vento, as already mentioned, sup- 

 plies the entire city of Havana with its water, the other serves to make 

 the region about Guines a garden, its waters being used for irrigation. 

 Other sul>terraiiean rivers in all probability have a sub-aqueous exit to 

 the south. 



The large spring at Vento rs the only one on the northern slope as far 

 as I Ivuow. The origin of the supply Issuing from the Vento Spring has 

 not been traced. But the region north of the Almendares River, being 

 shut out from a possiI)le contributing source, it midoul)tedly derives its 

 water from the tongue of the system of underground streams thrust into 

 tlie northern slope. An examination of the l)est availal)le map and the 

 levels of the Western and United Havana Railroads make it seem quite 

 certain that the Vento Springs derive their water from the region imme- 

 diately south of Vento and north of Rincon and Bejucal. This region 

 contains various sinks, without surface outlets, as well as dry sink-holes. 

 A notable sink-hole in this region is that at Aquada on the United Havana 

 Railroad. This is very broad, shallow and dry during the dry season, but 

 the water rises to stand over ten feet deep on the railroad track diu'ing 

 some of the wet seasons. All of these probal)ly drain into the Vento 

 Spring. 



It behooves the healtli aiithorities of tlie city of Havana to exer- 

 cise the strictest guard o\er tlie region Itetween Vento on the north and 

 Rincon and Bejucal on the south. Any contamination of sink-holes in 

 these regions is sure, during the wet season at least, to contaminate the 

 underground streams leading to Vento. An examination of the under- 

 ground channels in the Uost River region of Indiana has shown the main 

 underground channels to l)e provided with numerous smaller tributary 

 channels which in ordinary weather do not carry water but which do 

 carry water into the main stream after a long rain. At sucli a time any 

 tilth that may have accumulated in any of the sink-lioles over one of the 

 tributary streams is siu-e to find its way into tlie main stream. The same 

 is A-ery probalily true of the Vento supply, although on account of the 

 nature of the region it is not possible to follow the underground channels. 

 At present some of the sink-holes between Rincon and Vento are u^^ed as 

 cesspools and receivers of sewage. 



