It appears that Russia has let the tanks rolled and reclaimed the Crimea; re-claimed in that it was part of the Russian Empire/USSR for about a century before getting made part of Ukraine in the 1950s. They already had a big naval base in Sevastopol, a majority-Russian population and an electorate who liked the ousted pro-Russian Ukrainian president.
Most of the Crimea is basically a desert, with less annual rainfall than Los Angeles. It is impossible to sustain its 2 million people—including agriculture and the substantial tourist industry—without Ukrainian water. Current supplies aren’t even enough. In Sevastopol, home of the Black Sea Fleet, households get water only on certain days. In fact, on Feb. 19, when snipers were shooting protesters on the streets of Kiev, Sevastopol applied for $34 million in Western aid (note the irony) to improve its water and sewer systems.
The Crimea’s dependence on Ukraine for nearly all of it electricity makes it equally vulnerable to nonviolent retaliation. One suggestion making the rounds of the Ukrainian Internet is that the mainland, with warning, shut off the power for 15 minutes. It may not normalize the situation, but it could give Moscow pause.
Unless Russia wants to bring in generators and desalination plants (or a steady flow of water trucks from Russia) ASAP, they would be in position to have their lines of supply cut off in short order.
That would either force a Russian retreat or a Russian advance to grab enough of mainland Ukraine to secure those supplies.