Design Criteria Package for the Fisher Island 20-inch Water Main Replacement – MDWASD

Miami Dade County Florida

As owner’s representative for Miami-Dade Water and Sewer Department (MDWASD), LAN completed the preliminary engineering for this $85 million design-build replacement of a 20-inch water main between Port Island and Fisher Island. This project crossed under an environmentally fragile area of Miami Bay near the ship channel between some of the most congested, visible, and valuable property in the US.
LAN recommended a preferred route for the replacement, along with recommendations for design-build logistics and design criteria for the 20-inch water main. The Design Criteria Package (DCP) included the preliminary engineering, specifications, standards, and design criteria for 850 LF of 60-inch diameter steel-casing micro-tunnel at a depth of 100 feet.
Developing a complete and trustworthy DCP for this design-build project was essential due to the numerous internal and external stakeholders, including regulatory agencies. Using dry shafts with coffer dams situated in the bay at the island’s edge, staging on land while working on floating platforms, and the right design-build team were critical elements of this project. LAN provided the right combination of technical understanding, engineering, knowledge of local conditions, and alternative delivery experience to this project’s success.

At a glance

$85 million construction cost

100-foot depth

850 LF


Owner’s representative

Design-build procurement

Design Criteria Package development

Preliminary engineering

Alternative analysis

Stakeholder coordination


Alternative Delivery


Pipelines & Rehab


Miami Dade Water & Sewer Department

Related Work

Alternative Delivery

LAN City of San Antonio Soledad Main Street

Transportation Services

trenchless method identification, tunnel shaft design

Water Supply & Transmission