(f) the dune or bluff line, and 



(g) existing upland development. 



While it is impossible to predict the changes that will occur at a site 

 over a period of years, it is the responsibility of the reconnaissance engineer 

 to consider the possibilities to the best of his ability and establish the marks 

 with some degree of permanence. Even in the short run, changes are difficult to 

 predict, but good judgment and common sense help. In establishing a base line, 

 certain events can be considered likely: relative sea level will continue to 

 change, areas of rapid erosion will continue to erode, bluffs will recede, roads 

 will be widened or repaved, open areas will be developed, etc. The person es- 

 tablishing a base line must consider these incidents at the potential location 

 of each monument and the possible benefits of tying the base line into an es- 

 tablished grid system. 



While accessibility is important when a station is being established or 

 reestablished, the most accessible sites are often the most exposed. Acces- 

 sibility, therefore, must often be subordinated somewhat to other conditions 

 affecting the permanence of a mark. The most accessible sites are sometimes 

 not very representative of local conditions and trends. For example, a profile 

 line established at the end of a street is certainly accessible, but it is far 

 from representative of local conditions if the end of the street is followed by 

 a pathway or vehicle access over the dunes or by a storm drain outfall. Pro- 

 file lines, and therefore the base-line monuments, must be sited carefully to 

 accurately represent the area of interest. 



2. Protocol . 



A sometimes overlooked aspect of establishing a base line is the contacting 

 of property owners and local authorities. Local authorities and governing 

 bodies in the study area should be contacted in person, if possible, to answer 

 any questions that might arise so misconceptions concerning the purpose of the 

 study can be avoided. Frequently, local officials can provide valuable infor- 

 mation such as changes to monuments by local survey or maintenance crews, or 

 areas that experience unusual or recurring conditions that should be recorded 

 or avoided. If a personal visit is not possible, a letter should be sent be- 

 fore any surveying is done. Although this coordination is considered a courtesy, 

 failure to coordinate may produce bad feelings toward the Corps. 



Similar rapport must be established with the property owners upon whose 

 land a monument is to be established or whose land is to be crossed during a 

 survey. The contact should be in person, if possible, so the purpose and im- 

 portance of the study can be briefly and simply explained. A person who would 

 normally grant a request may resent what appears to be the taking of undue lib- 

 erties and refuse to give permission to use his property without his prior 

 consent. Unfortunately, once a person is committed to that attitude he is 

 likely to stick to it. If a personal visit to the landowner is not possible, 

 a letter explaining what is to be done and requesting his consent should be 

 sent to him along with a self-addressed franked envelope. Since some land- 

 owners in the past have neglected to reply, the letter should be written so 

 that failure to reply denotes consent. However, it is important to give the 

 owner a chance to state any objection he might have. If it is determined that 



