Preheat oven to 400°F.
With a vegetable peeler remove zest from lemon in strips and remove any white pith from strips. Coarsely chop enough zest to measure 1 tablespoon, reserving remainder for another use. Squeeze enough juice from lemons to measure 1/4 cup. In a flameproof roasting pan combine juice and chicken, tossing to coat, and arrange chicken skin sides down. Marinate chicken 15 minutes.
In an electric coffee/spice grinder grind zest, peppercorns, and salt until finely chopped. Arrange chicken, skin sides up, and pat lemon-pepper onto it. Roast chicken in middle of oven, basting occasionally, until just cooked through, 45 to 50 minutes. Transfer chicken to a platter and keep warm.
Add water to juices in roasting pan and simmer, stirring and scraping up any browned bits, until liquid is slightly thickened, about 2 minutes. Pour sauce over chicken.