Environmental Impacts

Extensive studies have been performed as part of the preparation of the Draft Environmental Document. The following is a summary of key points.

Hydrology and Floodplain

  • Project will add no more than 1.0 acre of additional impervious surface area​
  • No significant encroachment into a 100-year floodplain​

Water Quality​

  • No increase in pollutants during operation of the project​
  • Temporary best management practices will be employed to limit impacts during construction​

Hazardous Waste/Materials​

  • Five sites with potential hazardous waste or material concerns were identified within (or near) the project footprint​
  • Contamination may be present in soil and groundwater and will be properly transported and disposed of, if encountered​

Community Character/Cohesion​

  • No displaced residences, businesses, or community facilities​
  • Increased connectivity between neighborhoods and to Chinese Garden Park and Neptune Park​
  • Parking loss in downtown Oakland to accommodate safety, connectivity and accessibility for pedestrians and active transportation improvements


  • Noise levels in the design year will remain at existing levels​
  • Noise abatement measures were evaluated because existing conditions in the project footprint are at (or near) the Noise Abatement Criteria ​
  • Vibration measures will be employed during construction to avoid damage to nearby structures, including historic buildings​

Biological Resources​

  • No impacts to federally listed threatened or endangered species 
  • No impacts to sensitive habitats, such as streams and wetlands
  • Tree removal (approximately 35 trees) will occur and replacement will occur where feasible​
  • Preconstruction bird/bat surveys will be conducted to avoid impacts


Air Quality​

  • Not a Project of Air Quality Concern (POAQC)​


  • No displaced residences and businesses and no full property acquisitions anticipated​


  • Overall, the project will enhance the visual environment due to expanded views of the horizon, landscaping, and reduction of light shadowing​ with removal of the Broadway off-ramp
  • Mitigation is proposed for visual impacts to the Posey Tube​
  • Tree clearing will be offset by proposed landscaping​
  • Retaining walls will be treated with color, texture and/or patterning to enhance aesthetics and reduce the likelihood of glare and/or graffiti.

Parks and Recreational Facilities​

  • Approximately 1.52 miles of additional bike infrastructure will be built, improving connectivity within the project area
  • A sidewalk will be widened within Neptune Park in Alameda ​and a standard Class I bike facility will be provided
  • Continuous sidewalks will be constructed around Chinese Garden Park in Oakland​
  • Access to parks will be maintained at all times during construction​

Climate Change​

  • No additional greenhouse gas emissions during project operation​


  • Existing parking will be reduced in Oakland to accommodate project improvements

Cultural Resources/Section 4(f)

  • Adverse Effect on the Posey Tube (eligible for listing on National Register of Historic Places [NRHP]) and the Oakland Waterfront Warehouse District (NRHP-listed) ​
  • Memorandum of Agreement being prepared with the State Historic Preservation Officer (SHPO) and other consulting parties​
  • Individual Section 4(f) Evaluation prepared for impacts to the Posey Tube and the Oakland Waterfront Warehouse District ​
  • New right-turn lane from the Posey Tube to 5th Street would cause demolition of approximately 175 feet of the eastern wall​
  • New left-turn lane from Posey Tube to 6th Street would cause demolition of approximately 100 feet of the western wall​
  • Staircase removal on eastern wall of Posey Tube for installation of ADA-compliant ramp​
  • Final design for new wall will be completed in consultation with SHPO​ and other consulting parties

Existing (L) and proposed (R) Harrison Street Looking East toward I-880​

Existing (L) and proposed (R) Harrison Street Looking South at the Posey Tube​


  • Geology in the Oakland portion of the project footprint has a high potential to contain scientifically important paleontological resources​
  • Project may encounter fossils ​
  • Construction crews will receive environmental awareness training​
  • A paleontological monitor will be on-call during construction​
  • Any observed fossils will be evaluated, and if significant, will be recovered and donated to a recognized institution​