The authorities in Chisinau have signed a document leasing the Nistru River to Ukraine for 49 years. This agreement was made by oligarchs from Ukraine and Moldova.
No such agreement has been signed.
More detailed research shows that the information published on February 21st 2019 (while the electoral campaign was in full swing) was distributed by two sites - bloknot-moldova.md and kp.md - already a year and a half ago on October 22nd 2017. The primary source is a text published on the Kp.md site by environmental expert Ilia Trombitschi. This article covers the dangers of signing such an agreement with the Ukrainian side and does not state that a contract has been signed.
Further debunking from Stopfals.md.