DEAINAGE OF WET LANDS OF SOUTHERN LOUISIANA. 35 



slopes gradually from a height of about 3 feet above mean tide at the north end 

 to lake level at the south. Reclamation on this tract was started in 1907, and 

 the first extensive cultivation vs^as done in 1909. The condition and general 

 character of the muck has previously been described in the discussion of muck 

 soils. (See p. 12.) 



Levees. 



For the most part the levee was built of material taken from the outside of 

 the district. The work was done with a dipper dredge with a short boom, and 

 the berm on the outside is very small and in some places entirely lacking. 

 The levee was gone over two or three times before it was brought to its present 

 height of 4 feet above mean tide. The present crown is about 4 feet wide and 

 the side slopes are nearly as steep as 2 to 1. When this levee was built no 

 muck ditch was rhade in the base nor was any of the surface cleared of vegeta- 

 tion. The levee was cut by a trench some months after it had been built. 

 This showed that the material, when placed, did not force its way through the 

 muck and form a bond with the underlying silt. At this point the muck was 

 quite turfy in character, but not more so than the average muck of this part of 

 the prairie. The layer of muck under the levee was considerably compressed, 

 but it certainly was still quite pervious when compared to silt. The fact that 

 the base of this levee is above ordinary outside water level probably accounts 

 for the fact that no great amount of seepage appears. In the lower and softer 

 part of the district some of the material in the levee was taken from the reser- 

 voir canal. Here a berm of from 10 to 15 feet was left between the levee and 

 the canal, the muck being so soft that the mud, when dropped from the dipper, 

 undoubtedly cut through the muck to the silt below. The same condition 

 existed here as gave trouble on area No. 2, except that there was a berm on 

 the inside of this levee and the difference in the level of the water inside and 

 outside was never as great as on area No. 2. If the I'eservoir had been of suffi- 

 cient depth to drain thoroughly the lowest land in this district, the head of the 

 water against the levee might have been great enough to cause a noticeable 

 amount of seepage. During the fall of 1911 the reservoir was deepened about 

 3 feet and the material placed on the levee. As the levee has had a chance to 

 harden for several years since it was first built, it is not expected that this 

 increased depth of drainage will cause a greater amount of seepage through it. 

 In this case no damage seems to have resulted from placing the reservoir canal 

 close to the levee and from using the material excavated from it for levee 

 building. 



During the unusually high stage of water in this lake in December, 1911, and 

 January, 1912, the levees on the higher part of the district leaked very badly, 

 as might have been expected from a previous examination of the unbroken 

 layer of muck in the base. In the softer portions of the district no great 

 trouble was experienced from seepage. During the early months of 1912 a 

 continuous muck ditch was cut along the toe of the inside slope of these levees 

 and this refilled with material taken by an orange-peel bucket dredge from 

 the bottom of the outside canal. The levees should now be in much better 

 condition to resist seepage. 



Reservoir Canals. 



When this reservoir was first excavated the ground was very soft; as a 

 result a deep layer of mud was soon deposited in the bottom. Owing to the 

 fact that it was located in the lowest part of the tract it served as an outlet 

 to the lateral ditches, but never was of sufficient capacity to aid in reducing the 



