Build the Fence Now Act of 2011 - Amends the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 to require the Secretary of Homeland Security (DHS) to: (1) construct two layers of reinforced fencing along the entire international land border between the United States and Mexico; (2) provide for the installation of additional physical barriers, roads, lighting, cameras, radars, and sensors along the entire length of the international border between the United States and Mexico and the United States and Canada; and (3) complete such work within two years along the U.S.-Mexico border and within five years along the U.S.-Canada border.
Increases the FY2012 budget of the Tunnel Task Force (a joint Immigration and Customs Enforcement [ICE], Customs and Border Patrol [CBP], and Drug Enforcement Administration [DEA] force tasked to pinpoint smuggling tunnels) by 100% above the FY2007 budget.
Directs the Secretary to implement a program to fully integrate and utilize aerial surveillance technologies, including unmanned aerial vehicles, to enhance the security of the international borders between the United States and Mexico and the United States and Canada.