investigated, and amount of detail required from test results. Estuary 

 models generally vary in size from about 5,000 to 60,000 square feet, 

 excluding extremes such as the Gastineau Channel model (1,600 square feet) 

 and the Chesapeake Bay model (340,000 square feet). The cost of model 

 design and construction varies not only with the area of the model but 

 also with the complexity of the model geometry (i.e., pier slips, braided 

 channels, etc., as opposed to relatively flat bay bottoms, straight chan- 

 nels, etc.). Design and construction costs by WES have been on the order 

 of $12 to $15 per. square foot (March 1976); however, this does not normally 

 include the (direct) cost of major appurtenances (such as tide generators, 

 wave generators, hurricane surge generators, water supply pumps, etc.), 

 the model shelter, water supply sump, or model instrumentation. These 

 items are obtained with plant funds, and WES is reimbursed by indirect 

 charges to all projects. Construction time also varies with both the 

 size and complexity of the model (generally 1 to 8 months) . Most of the 

 model design is accomplished before initiating model construction; how- 

 ever, the design effort is usually continued into the early stages of 

 construction. The design is usually initiated 1 to 3 months before con- 

 struction. If prototype hydraulic, salinity, and shoaling data are avail- 

 able, they can be analyzed during this period. 



After completion of the model construction, a substantial period of 

 time is required for model verification. Since this is a trial -and-error 

 process, it is difficult to predict the time and cost required even for a 

 specific case. The time required for hydraulic and salinity verification 

 varies from about 3 to 15 months, depending on the size of the model, the 

 complexity of the estuary, the amount of prototype data available, the 

 niiraber of conditions (combinations of tide and freshwater discharge) to 

 be reproduced, the skill of the model personnel, and "luck." Operating 

 costs during this period will vary from about $8,000 to $15,000 per month 

 (March 1976) depending on the number of operating personnel, the amount 

 of support (shops, molding, photography, drafting, etc.), and the amount 

 of materials (especially salt) required. Fixed-bed shoaling verification 

 can also be a lengthy process requiring from 2 weeks to 3 months for each 

 reach to be studied. Monthly costs for shoaling verification will often 

 be 10 to 20 percent less than during hydraulic and salinity verifications 

 because fewer operating personnel are required. 



The testing program for a single study will generally require from 

 1 month to 1 year. However, several studies will probably be conducted 

 during the life of any one model. Operating costs will average about 

 $10,000 to $15,000 per month (March 1976). Costs may be significantly 

 higher during extensive water quality studies because of the greater 

 personnel and data reduction requirements. 



After completion of a model study the results are either published 

 in a single comprehensive report or in a series of reports on specific 

 studies conducted in the model. Test results are furnished to the spon- 

 sor in preliminary form as soon as they are available. Preparation and 

 publication of a final report usually requires about 6 months at a cost 

 of approximately $10,000 (March 1976). 



195 



