Jezeří Reservoir, Reservoir and cultural monument in Jezeří, Czech Republic.

The Jezeří Reservoir is a drinking-water dam on the Vesnický potok in the Jezerka National Nature Reserve, between the Jezeří and Jedlová hills. Its 86.4 m long, 17.54 m high curved dam wall is built of rough stone and leans upstream. The reservoir holds 0.053 million m³ and covers 0.64 ha.

Moritz von Lobkowitz had the dam built in 1902–1904 on his Jezeří estate to supply drinking water to villages including Kundratice, Jezeří, Holešice and Nové Sedlo, where his brewery stood. The engineer Müller designed it and the Vienna firm Rella carried out the work with Italian specialists; the cost was 500,000 crowns. Lobkowitz died in 1903 before completion, and the reservoir was named Moritz-Talsperre in his honour.

The reservoir is named after the Lobkowicz family: Moritz von Lobkowitz commissioned it, died in 1903 before completion, and the dam was long called Moritz-Talsperre. Its water once supplied villages such as Kundratice, Jezeří, Ervěnice, Holešice and Nové Sedlo, all later demolished for lignite mining.

The reservoir lies in a first-order drinking water protection zone and is not open to the public, so the dam and banks cannot be visited. It sits in the Jezerka National Nature Reserve, six kilometres north of Jirkov, on the Vesnický potok. Access is only along marked trails in the surrounding forest.

The dam is a curved retaining wall of rough-cut stone, 86.4 m long and 17.54 m high, built by the Vienna firm Rella with Italian specialists brought in for the job. Moritz von Lobkowitz, who ordered it, died in 1903 before completion and the reservoir was named Moritz-Talsperre in his honour.