1. Life at the Water’s Edge WHY is this important for reservoirs? John Hains 21 September 2006 Lake Greenwood State Park

2. Lakes versus Reservoirs I. Lakes and Reservoirs Have Different Characteristics, Origins II. Processes Occurring in Lakes Also Occur in Reservoirs III. There Are Additional Processes in Reservoirs

3. First: Solar energy drives the entire aquatic ecosystem. The lake’s characteristics are determined by the ways energy is processed, transferred, transformed, and expressed in temperature, weather, and water movement.

4. Second: The size, shape, geology, topography, vegetation, climate, land-use, and other human activity for the watershed affects the character of the lake.

5. Third: the internal fate of, and all the processes affecting water and materials in the reservoir, interacting with energy processes and depending on watershed processes - and thusly affecting patterns of stratification, sediment deposition, biological productivity, and water quality

6. Comparison of Natural Lakes to Reservoirs CharacteristicNatural LakesReservoirs DistributionMostly in glaciated regionsLocated mostly outside region also near rivers, theirof glaciation. Mostly in south floodplains and often associatedregion of U.S. Often in regions with karst regions or of water resource need. coastal plains. Drainage areaSmaller ratio of drainage area toLarger ratio of drainage areato lake surface area. Theoretical Longer, sometimes many yearsShorter, often less than 1 year. retention time LongevityLongerShorter ShorelineSimpler shape, shorterMore complex, dendritic, greater SD number

7. Comparison of Natural Lakes to Reservoirs, cont’d OutflowsMore stable, lake surface Releases according to fluctuations smallerdemand schedules, lake surface fluctuations greater Inflows Often many smaller Often dominated by one or a order streams few major inflows (sometimes other lake outflows). Nutrient This depends on the watershed characteristics loading and the size of the watershed. Water GreaterLesser, especially near clarity headwaters. Note: these last general relationships are less dependable than previous generalizations.

8. Lake NameShoreline length (km) Huron5118 Superior4796 Kentucky3830 Michigan2671 J. Strom Thurmond1930 Barkley1616 Hartwell1548 Erie1377 Kerr1287 Ontario1168 Champlain945 Lanier869 Norman837 Greenwood320 Tahoe116 The Reservoir Perspective

9. Lake Surface Area (sq. km) Shoreline (km) Shoreline Development Watershed Area (sq. km) Watershed/ Surface Area Huron5960061577.111341002.25 Superior8210047964.721280761.56 Kentucky648383042.44105151162.27 Michigan5780026713.131179122.04 J. Strom Thurmond 283193032.361596156.40 Barkley378161623.4545579120.58 Hartwell227154828.98540523.81 Erie2570013772.42781283.04 Greenwood4632013.31189141.12 Tahoe4951141.458121.60 Mendota4035.21.5760215.11

10. Lake Surface Area (sq. km) Shoreline (km) Shoreline Development Watershed Area (sq. km) Watershed/ Surface Area Greenwood4632013.31189141.12 Tahoe4951141.458121.60 Mendota4035.21.5760215.11

15. 20 km Lake Tahoe 2 km 5 km Lake Mendota Lake Greenwood Aerial Views of the lakes

16. Lake Surface Area (sq. km) Shoreline (km) Shoreline Development Watershed Area (sq. km) Watershed/ Surface Area Greenwood4632013.31189141.12 Tahoe4951141.458121.60 Mendota4035.21.5760215.11

17. In Conclusion: The fourth factor - shoreline complexity, length, and development – is a factor that can be important for reservoir ecosystems and water quality. And it is the only factor for which individual property owners have direct influence and control.

18. In Conclusion: The fourth factor - shoreline complexity, length, and development – is a factor that can be important for reservoir ecosystems and water quality. And it is the only factor for which individual property owners have direct influence and control. So the better question for lakeshore management is not “Why?” But rather “Why Not?”