If you haven’t seen the classic 60-second video Levee Spin 101, you missed what made Levees.org the talk of the town in 2007.

Defying a threat of lawsuit from the American Society of Civil Engineers (ASCE), Levees.org posted the satirical video to its website which immediately went viral.

With school children as actors, the video parodied the cozy relationship between the U.S. Army Corps of Engineers and a levee investigation team assembled by the ASCE post Katrina.

Represented pro bono by San Diego-based law firm Cooley LLP, Levees.org elected to exercise its right to free speech by publicizing the spoof. (The New Orleans-based law firm Adams and Reese also provided significant support.)

After the video release, two investigations of ASCE’s actions were launched.

In 2008, an external panel cited conflict of interest and admonished ASCE to discontinue allowing its peer review teams to be paid directly by the organization whose work they’re investigating.

In 2009, an internal ASCE panel announced that the Society had made false statements in a 2007 press release that gave a misleading impression that civil engineering failures during Katrina were not a cause of the flooding devastation. (ASCE had removed the release from its site by early 2008, an apparent acknowledgement of the errors.)

Last week, Levees.org received a letter from a Cooley LLP legal representative. It read:

“On December 12, 2007, we sent ASCE a letter informing them that Levees.org would exercise its First Amendment rights to comment critically on events of public concern and, to that end, would repost the video on December 14, 2007. Levees.org did just that and ASCE did not harass your organization further.”

The letter closes a very important chapter in Levees.org’s fight to squash the myths about the New Orleans flood that was then – and is still being pushed – by powerful interests.

ASCE’s harrassment of Levees.org and Levees.org’s triumph is evidence that a little grassroots group can win, even in the face of corporate attorneys with fat wallets and powerful organizations with government connections.