Basin Construction and Hydraulic Dredging

Fairmont Park’s three lakes make up about 40 acres of more than 180-acre park. After dredging, the depth of the lake will increase to about 7 feet, removing 2 feet of pasty silt that has accumulated from wind-blown dust, soil, fish and fowl feces which had settled on the bottom since the lakes were last dredged 25 years ago.

The cleanup will cost about $2 million, paid for through the Riverside Renaissance, a $1.8 billion city initiative that seeks to accomplish 30 years of projects within five years.


The cleaning will utilize two dredges pulling up about 160,000 tons of silt. The dredges will run five days a week, one around the clock, the other sun-up to sundown, said Dennis Thomas, president of JND Thomas Co. The vessels, one 25 feet long and the other 35 feet, use a hydraulic pump to suck up the sediment, sending it through thousands of feet of black pipe and into the basin. "It's the same concept as vacuuming a pool," said geologist Greg Middleton, who works for Leighton, the geotechnical consulting company hired for the project. "If you don't clean it, the material will build up and it will turn into a black lagoon."


Basin were constructed and restored to a level grass field. JND incorporated “sound and noise” reduction measures with all engine driven equipment that resulted in no complaints or imposition for the community.


All dredging operations were performed under direct supervision and in compliance with all local, state and federal regulatory agencies consistent with issued permits.


Relevant Project Elements

  • Hydraulic Maintenance Dredging at an Active Recreational Park
  • Full compliance; Storm Water Permits, Regional Water Quality & Air Resources Boards
  • Full Compliance with Dept of Public Works Project Labor Agreement.
  • Construction and Restoration of Settling Basins into leveled Grass Fields.
  • Operating 24 Hours Per Day, Six Days a Week with “Noise Reduction” Modified Equipment