picket fencing installed ($0.50 per linear foot), the cost of sand ac- 

 cumulated by the car bodies averaged about 85 percent more than the cost 

 of sand accumulated by the single picket fence. 



Additional studies should be made to determine the most practical 

 plan for erecting additional sand fences after sand has nearly or com- 

 pletely covered the original fence. A 4-foot fence installed directly 

 on top of the original fence produced dunes of high peak elevation, but 

 with a relatively narrow base or foundation (see Figure 8) . It was 

 difficult to dig post holes in new, soft, unstable sand to install a 

 second fence, 6 to 10 feet behind the first (see Figures 5 and 11) . The 

 feasibility of installing a fence, approximately 30 feet in front of the 

 original fence after it has been nearly covered, should be considered. 

 Further experiments should be planned to determine the feasibility of 

 this plan for increasing the size of the dune (see Figure 10) . The best 

 time for adding new fences under any of the three most likely plans should 

 be established during further experiments. Sand volume accumulations from 

 the second fence, whether installed on top of, behind, or in front of the 

 original fence line, were about equal. Maintenance of sand fencing is 

 important to produce valid data on sand accumulation for comparison of 

 various types and schemes of fencing. In addition, different sand fence 

 materials should not be used together in any one particular test section, 

 as was done in some of the first experiments. (See Figure 6, stations 100 

 to 600, where plastic mesh fence was installed on top of wood picket 

 fence.) In such instances, it was impossible to distinguish the amounts 

 contributed by the various types of fencing. 



Results from the experiment indicate that fencing materials with 

 porosities of 40 to 60 percent produce the best results for conditions on 

 the Texas coast. Further tests should show which materials and porosities 

 within that 20 percent range will be most efficient. 



The limited experiments with vegetation showed that rapid sand ac- 

 cretion near sand fences smothered certain plants. In other cases erosion 

 exposed roots of plants before they became established. Based on the 

 meager results of these tests, it appears that the more salt-, wind-, 

 and drought-tolerant native beach grasses will be the most productive in 

 future planting experiments, especially on the arid Padre and Mustang 

 Islands of the Texas coast. 



If possible, experimental planting and sand fence construction 

 should be located on beaches at least 2 feet above mean high tide to 

 minimize probable damaging effects from higher astronomical tides during 

 the equinox and surges generated by normal winds. 



Many photographs were taken during the dune experiments. A selection 

 of typical views are Figures 15 through 33. References to station loca- 

 tions in the captions of the pictures are the same as the lengths in feet 

 shown on plans of Figures 4 through 14. 



