Issuu on Google+

Lake Dredging POLLUTANTS ADDRESSED: Sediments, Nutrients and Organics, Salinity

DESCRIPTION: Dredging is an excavation activity in which materials are recovered from beneath the water's surface. The purpose is generally to gather bottom sediment and either dispose it at a different location or to excavate the roots of nuisance weeds which concentrate nutrients. By removing these nutrients the cycle of lake eutrophization can be terminated.

POTENTIAL TREATMENT AREAS: Lakes in agricultural/ranch lands Lakes in development lands ALTERNATIVE MANAGEMENT MEASURES: Pole/Post Planting Vertical Bundle Willow Fascines Brush or Tree Revetment

LOAD REDUCTION MECHANISM: Organics/Nutrients Management- Nutrients deposited in the lake by overland flow and stream waters, then absorbed by lake plants, are removed by dredging.

PERMITTING REQUIREMENTS: Requirements vary by location. A permit under sections 404 and 401 of the Clean Water Act, and/or county floodplain.

LAND USE CLASSIFICATION: Agricultural and Ranch Lands Disturbed Areas Urban Lands

Contact county regional flood control district.

ADDITIONAL BENEFITS: Open stream flow-lane and produce material to be used within-banks placement. It can be used to enhance or restore habitat. It method of weed reduction.

Arid Southwest BMP

21


Lake Dredging POLLUTANTS ADDRESSED: Sediments, Nutrients and Organics, Salinity Level 500: INTENSE ENGINEERING

LOAD REDUCTION POTENTIAL: LOW

MEDIUM

Riparian Planting Zone: Base flow/Toe Zone

HIGH

ESTIMATED TIME FOR LOAD REDUCTION: IMMEDIATE

MONTHS2 YEARS

> 2 YEARS

EXPECTED MAINTENANCE: LOW

MEDIUM

HIGH

ESTIMATED COST: LOW

MEDIUM

HIGH

PLANNING AND IMPLEMENTATION: Dredging requires a company that will work closely with your engineering team to utilize the right dredging equipment for your particular project. Each dredging project is different and therefore requires the equipment to be tailored for optimum project performance and a project feasibility studies, and cutter calculations are the professional assistance you will need.

Arid Southwest BMP

Photo courtesy of: Dredging Company, Inc http://www.dscdredge.com/dredgeapplications.htm.

22


Lake Dredging