66 MULTIPLE PURPOSE RIVER DEVELOPMENT 



headed Pickwick Landing, shows the contribution of the impound- 

 ment of Pickwick Landing to Kentucky powerhouse prime power 

 amounting to 0.3 megawatts (row two, column 1); while over into 

 the second column, the last entry for row two shows the at-site 

 primary power of Pickwick Landing, 87.6 megawatts, on the as- 

 sumption Pickwick was not benefited by upstream storage. At the 

 bottom of column two, of course, the 102.8 megawatts shown for 

 Pickwick Landing indicate the actual at-site prime power, taking 

 into account the upstream storage contribution. 



While this table is an illustration of the physical interdependence 

 among units of a system, a number of things are to be kept in 

 mind. In the first place, the operation of the hydroelectric system 

 is subject to constraints imposed by flood control and navigation 

 priorities. If the system were operated for power alone, the power 

 output would be somewhat larger because of the greater allowable 

 reservoir contents at the beginning of a critical dry period. Also, 

 without flood control limitations, there would be a longer critical 

 period. This must be kept in mind in any comparison of the data 

 in the table with a hypothetical operation of a single project for 

 power alone, which might in any particular case favor a single 

 project. 



For example, when operated in the system, the net contribution 

 to system output at Norris is only 29,000 kilowatts. If Norris had 

 been built as a power project and operated for power only as an 

 isolated project, primary power would have been about 47,100 

 kilowatts. Of course, as indicated in Table 2, Norris also contrib- 

 utes to power production at downstream plants in the amount of 

 25,200 kilowatts, making the total Norris contribution 54,200 kilo- 

 watts.^^ This relationship is generally true for the storage reservoirs, 

 such as Fontana and Cherokee. In the case of Watauga and South 

 Holston, the power generated in downstream plants is much greater 

 than that generated at the plant itself. 



Although the table will show how much the primary power at 

 run-of-river plants is increased by releases from storage projects 



^ Even the 54,200 kilowatts attributable to Norris would be larger if maximum 

 power output were the exclusive objective. Since the Norris facilities (dam and 

 reservoir) are operated to provide a "package" of services, of which power is 

 only one, the value of the product mix may exceed what the value of the power 

 would be if the system were operated for maximizing power output alone. 



