Four Mile Run and Hooffs Run Inlet Installation and Enhancement

The City is increasing inlet capacity throughout Four Mile Run and Hooffs Run watersheds.
Page updated on Oct 6, 2026 at 9:45 AM
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Project Summary

Phase: Design

Status: Active

Location: Potomac West

Managing Dept.: Project Implementation

Sponsor Dept.: Transportation & Environmental Services

Map of Alexandria showing the areas included in the Four Mile Run (East) and Hooffs Run watersheds.

Project Description

The City of Alexandria is making improvements to inlet capacity in the Four Mile Run and Hooffs Run watersheds. This grant-supported project will investigate the required increase in inlet capacity necessary to support extensive upgrades to stormwater infrastructure in the Four Mile Run and Hooffs Run watersheds - areas where a significant portion of the inland flooding within the City is experienced. Improvements will be proposed following analysis of the existing inlets within these areas. A pilot project area will also be identified to measure the efficacy of the proposed upgrades and inform the final project design. 

Additionally, the City is using this project to inform a larger flood mitigation strategy. The design and performance data collected during this project will be used to develop a repeatable approach to rapidly identify areas in the City where inlets can be installed to mitigate future flooding issues.

Photo of a newly installed curb inlet, the space along a road curb that allows water to drain off the road into the storm sewer system.
A photo of a standard concrete curb inlet that has been installed in an open excavation.
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Photo of a newly installed curb inlet, the space along a road curb that allows water to drain off the road into the storm sewer system.
This is a standard concrete curb inlet, which is an opening in the concrete curb along a road that allows storm water to enter into the City's storm sewer system.
A photo of a standard concrete curb inlet that has been installed in an open excavation.
This is a standard concrete curb inlet that has been installed in an open excavation. The structure is much larger than it appears when buried. Below the opening in the curb line is a large concrete vault with circular openings to receive storm sewer pipes.

Funding

Project Budget: $1,528,000

Funding Sources:

CIP Section: Stormwater Management

Learn more about the City of Alexandria's Fiscal Year Budget.

Schedule

  • Design Procurement: April 2025
  • Design Start: August 2025
  • Construction Procurement: January 2027
  • Construction Start: May 2027
  • Complete By: November 2027 

Planning

Progress Update

This summer, the project team continued to advance design development, procurement planning, and utility coordination to prepare the project for construction.

The City evaluated procurement strategies for construction services to ensure alignment with the project’s objectives and approved grant requirements. Following this review, the team decided to proceed with an Invitation to Bid (ITB) .

As part of the ongoing design coordination, the team evaluated options for addressing stormwater inlets affected by utility conflicts, including the possibility of deferring certain inlets to Phase II, which will continue the installation of additional new and upsized inlets throughout the Four Mile Run and Hooffs Run watersheds. After careful consideration, the City decided to defer several inlets to Phase II and continue working with utility providers to resolve the conflicts.  
The City also reviewed additional funding needs for survey services, utility coordination, and construction cost estimates. To advance utility relocation efforts, the City and its subconsultants met with Dominion Energy to discuss utility poles at several project locations. Work orders have since been initiated to begin the relocation process.

In addition, the City received and reviewed the 90% design plans. Biweekly project coordination meetings have continued throughout the summer to address outstanding design issues, coordinate next steps, and keep the project moving toward implementation.

The City remains committed to advancing the project through design and coordination to support the next steps toward construction.

Sponsor Program

Flood Action Alexandria logo

 

 

 

 

This project is part of the Flood Action Alexandria program. In response to more frequent, intense climate-change-induced storm events, the City of Alexandria launched Flood Action Alexandria, a multipronged program to help address flooding issues in our community.