190 GEOLOGICAL RECONNAISSANCE OF THE DOMINICAN REPUBLIC. 



Much of the gently rolling plain that stretches eastward from Rio 

 Yaque to Azua is a waterless wilderness. Rio Tabara drains the country 

 that extends southward from Las Yayas almost to Puerto Viejo. It is 

 nearly 50 kilometers long, but as a large part of the country it crosses has a 

 somewhat scanty rainfall the stream is ephemeral except in its upper part, 

 where there is probably some flow at all seasons. 



Rio Jura is a similar stream somewhat shorter than the Tabara. It 

 drains the country just east of that served by Rio Tabara. When seen 

 in June, 1919, near Azua it contained a small quantity of water and may 

 not completely dry up at any season. 



The eastern part of the Province of Azua is drained by Rio Ocoa and its 

 tributaries and by the headwaters of Rio Nizao. Rio Ocoa is about 65 

 kilometers long. It flows in a rock gorge above Arenoso, but below 

 Arenoso it widens and flows in braided channels in a gravel bed. Rio 

 Nizao is 80 kilometers long, about 35 kilometers of which are in the Prov- 

 ince of Azua. Throughout its course it is a swift stream and flows over 

 many rapids. 



A number of short streams flow into Lake Enriquillo from both the north 

 and the south. Rio de las Damas, which passes through Duverge, was 

 the only one examined during this investigation except the very short 

 streams fed by springs near the lake. Rio de las Damas is about 15 kilome- 

 ters long. It is about 8 to 10 meters wide and nearly 2 meters deep at 

 Puerto Escondido, and only about 3 meters wide and 1 meter deep above 

 Duverge. Part of the loss between these places is caused by irrigation in 

 Escondido Valley, but part is probably due to seepage into the cavernous 

 limestone which here forms the country rock. On this stream between 

 Puerto Escondido and Duverge there are said to be two waterfalls that 

 may furnish water power. 



Several fair-sized streams about 30 kilometers in length flow into the 

 sea along the coast south of Barahona, among them Rio Bahoruco, Rio de 

 los Patos, and Rio Cito. 



LAKES. 



Lake Enriquillo is by far the largest inland body of water in the island. 

 As already stated, it occupies a depression which in Pleistocene time was 

 probably an arm of the sea and which was probably separated from it by 

 delta deposits of Rio Yaque together with a regional elevation of about 

 35 meters. Although the lake receives more or less water from Rio Yaque 

 in times of flood and a considerable volume from springs and streams, it 

 appears to be progressively shrinking through evaporation. Its surface 

 now stands about 44 meters below sea level. The map of Enriquillo Basin 

 made by James W. Wells l in 1893 gives the altitude of Lake Enriquillo 



1 Wills, J. \\'., A survey journey in Santo Domingo; West Indies: Roy. Geographic Soc. Supplementary 

 Papers, vol. 3, 1893. 



