Normal urine specific gravity levels are between 1.000 and 1.030. Medscape defines the specific gravity of urine as the measure of urine density ratio compared to water density.
Specific gravity is measured to observe if the kidneys are concentrating urine efficiently, as well as, the concentration of every chemical particle present in the urine. MedlinePlus explains that the test is usually performed before and after water loading, water deprivation, or antidiuretic administration. It also is usually part of a routine urinalysis. After excessive water intake, the value is expected to be 1.001. If you are avoiding fluids, the urine specific gravity level should be above 1.030.