Uncontrolled dacha construction is swallowing up protected land bordering Moscow reservoirs and threatening to pollute city water supplies, according to Moscow water officials and ecologists.Galina Seleznyova, an expert at Mosvodokanal, the city body in charge of water supply and cleaning, said all nine of the reservoirs in the Moscow region that supply the city are affected to varying degrees by construction that contradicts legislation designed to protect water sources."When we see where this could lead, we have to sound the alarm," she said.The Moscow area has seen a boom in the construction of new dachas -- or kottedzhi as the larger and fancier versions of the traditional country houses are called -- to accommodate Russia's new rich. According to Seleznyova, picturesque areas close to reservoirs are particularly sought-after.But she said such construction can pollute the reservoir in a variety of ways: sewage from newly constructed houses can contaminate water sources, while uprooting or cutting down trees, laying roads, and asphalting areas around new housing disrupts the delicate ecological balance that maintains the purity of reservoir water.According to Seleznyova, Soviet laws still in existence forbid construction within one kilometer of a reservoir -- on so-called "water-protection zones." In larger areas around reservoirs, called "zones of sanitary protection," building can only go ahead with the permission of local sanitary authorities.But she said that such legislation conflicts with newer laws giving local authorities control over the land. These laws make no mention of limitations on construction.As a result of this legal confusion, Seleznyova said local authorities, who tend to see the areas not in terms of their ecological significance but in terms of their commercial potential, are able to rent out land for dacha construction "turning a blind eye" to the old legislation.Quite apart from the environmental damage and health hazards of such construction, Seleznyova pointed out that Muscovites would in the end suffer financially, as the cost of cleaning up the water would drastically force up the currently nominal 40-ruble-a-month water fees. Nikolai Shalimov of the environmental group Moscow Ecological Federation singled out the Istrinskoye reservoir, 50 kilometers northwest of Moscow, as one of the worst examples of construction on supposedly protected land."There are houses there 20, 30 meters from the water," he said. "I took a visitor from an American environmental group to Istrinskoye and she simply burst into tears."Both Shalimov and Seleznyova said that only legislation designating such areas federal property would prevent future abuses.Moscow water authorities insist that city water is safe to drink, although many residents boil it before use. Seleznyova said that, for the moment, the quality of the city's water has not suffered as a result of construction on land near reservoirs, but she said that if controls were not introduced that situation could change."If we do not respect the law," she said, "what started with construction will end with polluted water flowing into the system."