What is "conservators of the river thames"

Conservator \Con"ser*va`tor\ (?; 277), n. [L.: cf. F. conservateur.]

1. One who preserves from injury or violation; a protector; a preserver.

   The great Creator and Conservator of the world.
   --Derham.

2. (Law)

   1. An officer who has charge of preserving the public peace, as a justice or sheriff.

   2. One who has an official charge of preserving the rights and privileges of a city, corporation, community, or estate.

      The lords of the secret council were likewise made conservators of the peace of the two kingdoms.
      --Clarendon.

      The conservator of the estate of an idiot.
      --Bouvier.

      Conservators of the River Thames, a board of commissioners instituted by Parliament to have the conservancy of the Thames.