Two or more improvement districts formed for a purpose other than the incurring of bonded indebtedness, whose powers and purposes are limited to those specified in Article 3 (commencing with Section 71680) of Chapter 3 of Part 5, and which are portions of the same district, may be consolidated for a purpose other than the incurring of bonded indebtedness, as provided in this chapter, whether their boundaries are contiguous or not.