any decree entered in the general stream adjudication confirming the Navajo Nation water rights and shall not be precluded from making claims to water rights in the general stream adjudication. Allottees, or the United States, acting in its capacity for allottees, may make claims, and such claims may be adjudicated, as individual water rights in the general stream adjudication. 12. Antideficiency The United States shall not be liable for any failure to carry out any obligation or activity authorized by this Act (including any obligation or activity under the agreement) if adequate appropriations are not provided expressly by Congress to carry out the purposes of this Act.