I hope the following simplified version is what you need.
It might liik nicer if you/someone can provide me some nice picture to used as background image.
You can drag the slider or drag the water level (move mouse near center of water level) and drag it up/down.

/htdocs/ntnujava/ejsuser/2/users/ntnu/fkh/hydroelectricstation_pkg/hydroelectricstation.propertiesFull screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
Download EJS jar file(1263.3kB):double click downloaded file to run it. (20 times by 10 users) , Download EJS source (3 times by 3 users) View EJS source