Frequently Asked Questions

Yes. CDID #1’s ditches are considered Waters of the U.S. and subject to the Clean Water Act.

Discharges to our ditches must meet City of Longview or Cowlitz County stormwater requirements, and comply with the 2019 Stormwater Management Manual for Western Washington. 

Permitted Discharges

Discharges from our ditches to surface waters are permitted as a Municipal Separate Storm Sewer System (MS4) under the Western Washington Phase II Municipal Stormwater National Pollutant Discharge Elimination System (NPDES) permit. As a Phase II Secondary Permittee, CDID #1 is required to also adopt and implement its own Stormwater Management Program (PDF) to control stormwater flows, educate the public, eliminate illicit discharges and reduce contaminated runoff.

An illicit discharge is any discharge to a municipal separate storm sewer (MS4) that is not comprised entirely of stormwater or of authorized non-stormwater discharges permitted under an NPDES permit.  Some non-stormwater discharges may be allowable, such as flows from fire fighting activities and air conditioning condensate.  Outdoor washing acitivites that flow to a storm drain inlet may be considered an illicit discharge if the water becomes contaminated with roadway pollutants as it flows across driveways and along curb/gutter.  

Illicit discharges including most non-stormwater flows, illegal dumping, or improper disposal of hazardous materials, pet waste, yard debris and litter are strictly prohibited in CDID #1 ditches. Only certain non-stormwater flows are allowed including:

• Air conditioning condensation
• Discharges covered by another National Pollutant Discharge Elimination System (NPDES) permit
• Diverted stream flows
• Emergency firefighting water
• Flows from riparian habitats and wetlands
• Footing drains
• Foundation drains
• Irrigation water from agricultural sources
• Rising groundwater, or uncontaminated groundwater (pumped or infiltrated)
• Springs
• Water from crawl space sumps

Only if you contact us in advance to authorize it! Swimming pool and hot tub water must be dechlorinated to a concentration of 0.1 parts per million, pH adjusted and possibly re-oxygenated before being discharged. Discharge volume and flow must be controlled to prevent erosion and the re-suspension of sediment in the ditch. Pool and hot tub cleaning wastewater and filter backwash may not be disposed of in the ditch.

Other Prohibited Discharges

Other potable water discharges are also prohibited, such as from:

• Dust control waters
• Fire hydrant flushing
• Irrigation runoff
• Lawn watering
• Washdown waters
• Water line flushing

CDID #1 is required to implement and enforce a Stormwater Management Program (PDF) to reduce pollutants in stormwater runoff to our ditches from new development, re-development and construction site activities. The program applies to both private and public improvements, including roads, and is consistent with stormwater regulations adopted by the City of Longview, City of Kelso and Cowlitz County. CDID #1 coordinates with these local jurisdictions to permit and manage projects within our system boundary.

Notify Us

If you already have a CDID #1 encroachment permit and are ready to start work, notify us at least 48 hours in advance. Depending on the project, CDID #1 may inspect the site to ensure appropriate temporary erosion and sediment controls are in place, and/or request a pre-construction meeting with you or your contractor.