The average annual rainfall is 132 cm (52 inches). Generally, the periods 

 of highest rainfall occur in July and August, and the periods of lowest rainfall 

 occur in September and October. 



Temperatures range from around -7oC (20OF) in December and January to a 

 high of 350c (95°F) in July and August. Temperature extremes for the 1947-59 

 period were -120C (11°F) and 38°C (lOOOp) (data from Hackberry, Louisiana, 

 weather station). 



Sabine Refuge is subject to occasional hurricanes, which typically develop 

 and strike the gulf coast during late summer and fall. Storm-associated damages 

 result from the effects of high-velocity winds and/or flooding. Although the 

 barrier cheniers on the south afford some degree of protection, the high tides 

 enter refuge lands via Sabine and Calcasieu Lakes and the channels penetrating 

 the refuge. 



Hydrology . The Sabine and Calcasieu Rivers empty into the lakes bearing 

 their names. Both these lakes are important shipping lanes, and their openings 

 into the gulf have been enlarged to facilitate ship traffic. Because the inter- 

 change of water is rapid, the salinities of the nearshore gulf and these lakes 

 are generally similar. The refuge ground elevations are low and are greatly 

 affected by tide levels and the Sabine and Calcasieu Lake levels. 



Several large systems of bayous originally drained the refuge marshes to 

 the west, south, and east. The drainage pattern of the western section of the 

 refuge has been completely altered by canals. Similar canals now border the 

 perimeter and dissect the refuge such that Calcasieu Lake, Sabine Lake, and 

 the Gulf of Mexico are interconnected. Fresh water that drains from the marsh 

 is therefore mixing with waters from these artificial estuaries. Natural bayous 

 are miostly blocked or otherwise altered. Wood weirs and earthen plugs were 

 originally placed at intersections of canals and natural drains. But these 

 have since deteriorated, and saline water can now intrude throughout the network 

 of canal systems which permeates the refuge. 



Several impoundments have been constructed on the refuge (using levees), 

 but they are plagued with maintenance problems. Presently, only one impoundment, 

 containing 2,064 ha (5,100 acres) is functional. Rainfall is the sole source 

 of fresh water; the optimal water depth is about 1.2 m (4 ft) above mean sea 

 level . 



There are relatively large supplies of hard (100-200 mg/1 ) water in south- 

 western Louisiana. Wells, ranging in depth from 60 to 210 m (200 to 700 ft), 

 tap the Chicot aquifer, comprised of Pleistocene formations. Before the 

 mid-1940's, the direction of groundwater flow was gulfward. Heavy pumping in 

 the Lake Charles area has occurred since that time, and a cone of depressed 

 groundwater level has developed. This changed the direction of coastal 

 groundwater movement toward the north. 



74 



