[ssschev]

... but just a warning, that first one would make Oregonians criminals...
~~~~~~~
Not quite accurate.

http://www.ncsl.org/research/environment-and-natural-resources/rainwater-harvesting.aspx#or
Oregon

Rainwater harvesting is allowed in Oregon, but may only be done from roof surfaces. Oregon allows for alternate methods of construction of rainwater harvesting systems (Or. Rev. Stat. §455.060). The Oregon Building Codes Division (BCD) has approved the use of rainwater harvesting systems as an alternate method to the state plumbing code and created methods for both potable and non-potable systems.

Senate Bill 79 (2009) directs the BCD to increase energy efficiency by including rainwater harvesting, in new and repaired buildings.

Additional Resources: Oregon Smart Guide - Rainwater Harvesting

Ponds are a different story regardless of size.

[little jeremiah]

I live in SW OR and since the climate is very arid here, water rights are an important part of rural life; also in parts of rural CA.

Catching runoff does prevent the water from going into the water system, and taking water from creeks and rivers is regulated. People who live where it rains all year round wouldn’t see the need of regulating these waterways but it makes sense here.