EXPERIMENTAL DUNE RESTORATION AND STABILIZATION, 

 NAUSET BEACH, CAPE COD, MASSACHUSETTS 



by 

 Paul L. Knutson 



I . INTRODUCTION 



1. General . 



Many coastal harbors and waterways are sheltered by sandbars, sandspits, 

 and barrier beaches — formations which absorb the brunt of wave attack during 

 severe storms. One or more natural inlets through these bars and beaches often 

 provide navigational access to the ocean. These inlets may migrate considerable 

 distance over time as old inlets are filled by littoral drift processes and new 

 inlets are formed by storms. Newly formed or recently disturbed parts of bar- 

 rier formations are typically unstable, consisting of unconsolidated sands and 

 gravel. More mature reaches may support stands of beach grass and other vegeta- 

 tion which trap blowing sand and build dunes, providing a measure of stability. 

 However, severe storms, grazing, and foot and vehicular traffic may degrade even 

 matur,e areas and make them unstable. 



In some cases, barren parts of emergent formations contribute significant 

 quantities of windblown sand to the bays or lagoons they protect, often causing 

 an increase in maintenance dredging requirements and damaging navigation chan- 

 nels and shellfish beds. In addition, the instability of these areas may con- 

 stitute a threat to existing facilities. In such cases, considerable benefit 

 may be realized by encouraging and accelerating the natural barrier beach 

 formation and stabilization processes. 



This study evaluates the effectiveness of several alternative stabilization 

 techniques on a newly formed barrier beach. 



2. Study Objectives . 



The objectives of the' experiment at Nauset Beach (Fig. 1) were to (a) deter- 

 mine if standard methods of dune restoration and stabilization, developed along 

 the gulf and South Atlantic coasts, could be applied to the North Atlantic 

 coast, and (b) determine the best methods and materials needed in the design 

 and construction of dune stabilization projects. More specific information on 

 materials, techniques, maintenance, and costs is provided in Knutson (1977) and 

 Woodhouse (1978) . 



3. Previous Work . 



a. General . Considerable research has been conducted to develop workable 

 sand stabilization techniques for use in (a) creating or restoring dune systems 

 as barriers to the inland penetration of waves and storm surges, and (b) slowing 

 or halting the inland migration of coastal dunes. The most widely used tech- 

 niques involve the installation of wooden or fabric fences and the planting of 

 native beach grasses. 



Wooden or fabric fences create a region of low wind velocity which causes 

 wind-transported materials to deposit and accumulate. The most commonly used 



