Changes

* [http://www.ehow.com/how_6713156_calculate-runoff-coefficient.html How to Calculate Runoff Coefficient]. Rain is a normal phenomenon for many mid-latitude areas. It creates runoff, a term for water movement. A runoff coefficient is a number that relates the rainfall rate and runoff rate. Using the runoff coefficient, scientists and hydrologists can calculate how much water passes over a given area per second. There are two ways you can find the runoff coefficient. One is by using the Rational Method, and the other is by using a runoff coefficient table.

* [http://www.waterforaridland.com/Books/book%201water%20from%20rock%20outcrops.pdf Water from Rock Outcrops: A handbook for engineers and technicians on site investigations, designs, construction and maintenance of rock catchment tanks and dams] or ([http://www.washdoc.info/docsearch/title/156042 alternative link]). A full project guide from start to finish, on building a dam in a natural rock catchment. Includes building options, how to measure and calculate, how to organise the community, how to fund raise and make a proposal, costs, and more.