For the more information about water resources in the National Park Service, please visit http://www.nature.nps.gov/water/.
Bi-National Border Cooperation on the Rio Grande
Forming the international border between the United States and Mexico in Texas, the Big Bend Reach of the Rio Grande is the centerpiece of an emerging bi-national conservation area in the northern Chihuahuan Desert. Today's Rio Grande is a small caricature of the river that dominated the region a century ago. Declining flows, channel sedimentation, and invasive vegetation have transformed the river from a wild, ever-changing, multi-threaded channel into a constricted, stable, single-threaded channel that provides greatly reduced aquatic and recreational value.
An altered hydrologic regime within the Rio Grande has led to an accumulation of sediment, essentially choking the river, leaving less room for water and aquatic habitat; in its natural state, the river eventually flushed sediment all the way into the Gulf of Mexico. In addition, the exotic species giant cane (Arundo donax) and saltcedar (Tamarix spp.) line the banks of the Rio Grande, anchoring sediment and making it even harder for the river to flush sediment downstream, reducing the river channel's capacity to convey water. When there is a big surge in water flow—as often happens during the rainy season—the water overflows its banks and inundates the floodplain. Reduced channel capacity means those flood waters reach further out onto the floodplain, or worse, into communities that aren't prepared.
Low flows mean an ever growing problem with water quality. Increasing salinity and nutrients are recognized problems throughout the western portion of the Big Bend reach. Fortunately, in the eastern portion of the Big Bend reach, the Lower Canyons includes many fresh water springs that dilute water quality problems and effectively ensure high quality year round boating. Springs issue forth from a large regional aquifer that extends from far west Texas to the Hill Country and into Mexico. These springs are an important water source for aquatic and terrestrial wildlife and river runners. Producing almost 200,000 acre feet a year, these springs also play an important role in maintaining water quality in the Amistad Reservoir.
In 2010 President Obama and former President of Mexico Calderon issued a statement highlighting the importance of conservation of the Rio Grande and other regional resources, touting it as one of the most significant ecological complexes in North America. Secretary of Interior Salazar and his previous counterpart in Mexico, Secretary Elvira, have worked together to build bi-national conservation capacity for protected areas and private lands assistance programs in west Texas and northern Chihuahua, including activities that increase bi-national conservation capacity, yielding environmental benefits and increasing border security. Protected areas in the region include Big Bend National Park and Rio Grande Wild and Scenic River and the Mexican federally protected areas of Maderas del Carmen, Ocampo, Canyon de Santa Elena, and the Rio Bravo del Norte. Additionally, the state of Texas manages two large areas in the region: Big Bend Ranch State Park and Black Gap Wildlife Management Area. Finally, the conservation value and potential of the region is supported by the remoteness of the region, the presence of large ranches, and the absence of large population centers.
In 2010 federal and state land managing agencies signed a Memorandum of Understanding to form the Big Bend Conservation Cooperative to foster communication between the agencies and to provide a forum for the public to speak to and hear directly from conservation professionals. In 2011 the cooperative along with Mexican counterparts received support from the Commission for Environmental Cooperation to develop and implement shared conservation projects and a sustainable economic development of small communities within in the Mexican protected areas. The project has led to the development of a bi-national Conservation Assessment and an economic development plan for the riverside town of Boquillas, Coahuila, Mexico. During a recent visit to the Big Bend region, Assistant Secretary of the Interior Anne Castle noted the Big Bend Conservation Cooperative's efforts to conserve the Rio Grande watershed as a model of the kind of partnership that is the foundation of President Obama's America's Great Outdoors Rivers Initiative.
From bighorn sheep at the top of rugged mountains to Rio Grande silvery minnows at the bottom of the Rio Grande, a diverse array of natural and human communities depend on the grasslands, mountains, rivers, creeks, and springs of the Chihuahuan Desert. The Big Bend Conservation Cooperative is working with a diverse group of public and private partners on both sides of the river to increase the effectiveness of conservation and restoration efforts in the Big Bend. Resource managers at Big Bend National Park along with our colleagues in the Big Bend Conservation Cooperative are encouraged by recent progress and are fully engaged in producing a future of greater conservation and appreciation for the ecosystem services the people and wildlife of the Chihuahuan Desert rely on.
Last Updated: March 25, 2013