In accordance with Royal Decree 650/1987, of May 8, the Segura Hydrographic Confederation comprises the territory of the hydrographic basins that flow into the Mediterranean Sea between the mouth of the Almanzora River and the left bank of the Gola del Segura at its mouth; also the Rambla de Canales hydrographic basin and the Yecla and Corralrubio endorheic basins.
With an approximate area of 18,870 km², it affects four autonomous communities, almost completely the Region of Murcia and partially the communities of Andalusia (provinces of Jaén, Granada and Almería), Castilla-La Mancha (province of Albacete) and Valencia (province of Alicante).
In article 2, section 2, of ROYAL DECREE 125/2007, of February 2, which establishes the territorial scope of the River Basins, it is established that the Segura River Basin includes the territory of the hydrographic basins that discharge into the Mediterranean Sea between the mouth of the Almanzora river and the left bank of the Gola del Segura at its mouth, including its transitional waters; also the Rambla de Canales hydrographic sub-basin and the Yecla and Corral-Rubio endorheic basins. The coastal waters have as a southern limit the line with a 122º orientation that passes through the Puntazo de los Ratones, north of the mouth of the Almanzora River, and as a north limit the line with a 100º orientation that passes through the coastal limit between the municipalities of Elche and Guardamar del Segura. Also in the single transitory provision. "Provisional assignment of the basins not transferred" of said decree establishes that: