Water Reservoir Within the Karst Field Overburden: Gusić Polje, Croatia

• Main Authors: Ante Pavičić, Davor Benamatić, Damir Pešt, Marijan Marasović
• Format: Article
• Language: English
• Published: Croatian Geological Survey 2002-06-01
• Series: Geologia Croatica
• Subjects: Surface water reservoir; Karst; Water losses; Geophysical investigation; Gusić polje; Croatia
• Online Access: http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/247

<div>The Gusić reservoir is a compensation basin constructed in the karst</div><div>field. The reservoir lies on a Quaternary overburden free of ponors</div><div>(sinkholes) and suffosions. After the reservoir filling the water losses</div><div>were up to &lt;6.4 m3/s. The bottom impermeability has been ensured</div><div>with a 0.4 m thick clay base blanket. During reservoir exploitation,</div><div>suffosions and ponors developed through which 2 m3/s water was</div><div>lost. Such conditions required reservoir repair within a short time</div><div>frame of approximately 10 days during which the power plant was</div><div>shut down. When the reservoir was emptied, a resistivity sounding</div><div>(Wenner electrodes arrangement at five depth levels) was conducted</div><div>on the reservoir bottom and clay blanket. An alternative concept has</div><div>also been considered - the construction of a new reservoir area that</div><div>has similar hydrogeological conditions. The solution for the possible</div><div>impact of groundwater (air) &Ograve;pressure&Oacute; could be the construction of a</div><div>horizontal &Ograve;vent&Oacute; in the deepest part of the palaeodepression, where</div><div>the bedrock karstification is the most intensive and the interrelation</div><div>between groundwater and air pressure on the overburden is possible.</div><div>The reservoir bottom impermeability could be resolved with a clay</div><div>blanket or with synthetic materials.</div>