There are two main issues with hydroelectric power (the power density of the two are not easily comparable as their is too much spatial variability in each):
1) Ecosystem disruption (inundation of land as well as blocking migratory aquatic species and significant changes in the downstream water temperature).
2) Almost all of the potential hydroelectric sites in the US (and much of the developed world) have already been utilized (e.g., [1],[2]). That is, capacity can't really expand much. However, the potential for pumped storage (which is not an energy source) is still high.
Wind power production is still nowhere near at capacity even though it suffers from the deficiencies relative to hydro that you have mentioned.
1) Ecosystem disruption (inundation of land as well as blocking migratory aquatic species and significant changes in the downstream water temperature).
2) Almost all of the potential hydroelectric sites in the US (and much of the developed world) have already been utilized (e.g., [1],[2]). That is, capacity can't really expand much. However, the potential for pumped storage (which is not an energy source) is still high.
Wind power production is still nowhere near at capacity even though it suffers from the deficiencies relative to hydro that you have mentioned.
[1] Smil, Energy Myths and Realities (Excellent, highly recommended), http://www.amazon.com/Energy-Myths-Realities-Bringing-Scienc...
[2]: Prentiss, Energy Revolution: The Physics and Promise of Efficient Technology (not that good if you've read other books on the subject), http://www.amazon.com/Energy-Revolution-Physics-Efficient-Te...