In a medium heavy pot, over medium heat, place rhubarb, sugar and water. Bring to a boil, stirring to dissolve the sugar. Reduce heat and simmer for 45 minutes, stirring occasionally.
Strain the syrup through a fine mesh sieve into a large measuring cup. Press the rhubarb with the back of a spoon to extract all the juice. Discard the rhubarb and return the syrup to the pot. Add the juice of two oranges. Simmer over low heat for 15 minutes to reduce to thick syrup.
Cool and store in an airtight glass jar in refrigerator for up to 3 weeks.
The story on rhubarb + other recipes:: A First Sip of Spring: Rhubarb.