Contact Us: City Hall Address: 2263 Santa Clara Avenue Alameda, CA 94501 (510) 747-7400 The Construction phase typically takes 6-12 months.Most ADU projects take 12-18 months to complete, but some extend to 24 months or more. The City is continually seeking vendors, suppliers, and contractors who can provide quality products and services at competitive prices. Landscape and irrigation contractor. Original contracts and their amendments for all water contractors are available in PDF format, on request. Explore County contracting opportunities in goods, services and construction. Use the table below to explore contract opportunities for goods and services. A new online portal for customers to apply for water use efficiency programs, track the status of their applications, and more!