In the middle stretch of the river there are a large number of lagoons that are fed directly from the river
aquifer due to its natural dynamics, which causes the water to circulate through the ground. Where the ground is below the water table, lagoons form in the
meanders abandoned by the
Ebro or its tributaries or in hollows of the land due to subsidence because the
subsoil plaster is dissolved by the groundwater and ends up collapsing forming
chasms or
sinkholes that when water emerges are popularly called "
Ojos" (Eyes). They are part of this abundant set present or buried for cultivation, for example the lagoons of
Larralde,
Ojo del Fraile,
Ojo del Cura and
Galachos, all around
Zaragoza capital, but they are numerous in any other province of the riverbed. These lagoons or flood lakes are more common in the middle stretch of the
Ebro. There are also numerous
endorheic lagoons such as the
Sariñena lagoon in
Huesca, the Montcornés lagoon in
Lérida or the salty lagoon of
Chiprana (
Zaragoza). The largest in the area of the Ebro Hydrographic Confederation is the
Gallocanta lagoon, located in an endorheic basin, with no external outlet of 541 km2 of basin, which forms one (when it is completely full) or three lagoons depending on the amount of rainfall it receives. The endorheic lagoons that still persist are the remains of the
Cenozoic seas or
Pliocene residual lakes and usually have a very characteristic and rare endemic fauna and flora with some large species such as the
crane,
flamingo, or the
alcaraván. Among the
wetland projects are the restoration and conditioning of the
El Cañizar lake in Villarquemado, (Teruel), and that of Bayas, in Miranda de Ebro (Burgos), completed in 2010; the improvement of the Ojos de Pontil, in Rueda de Jalón (Zaragoza) and the conditioning of the wetland environment in La Sima, in Rubielos de la Cérida (Teruel), both completed in 2011. The organization is also carrying out the environmental
restoration of the wetland of the Guaso riverbank on the right bank of the
Ara river, in
Aínsa (Huesca) and the improvement and conservation of the
Larralde pond (Zaragoza) and the restoration of the riverbed of the
Queiles river in
Los Fayos (Zaragoza). But the great wetland of the basin is located in the Mediterranean, the Ebro Delta, of 7,736 hectares. It is a
Ramsar Convention site, ZEPA area and Tierras del Ebro Biosphere Reserve. File:Delta del Ebro Anedes.JPG|The flood lake of the
Galacho de Juslibol during a flooding of the Ebro River File:Terreno anegado después de las lluvias - panoramio.jpg|The
Ojo del Cura is a typical karstic lagoon located in the middle Ebro, fed by the overflow of the river aquifer. File:Anegado.jpg|The flood lake of the Galacho de Juslibol during a flooding of the Ebro River == Confederation reservoirs ==