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SEPA checklist guidance, Section B: Surface water

We provide guidance to help applicants complete the Surface water subsection of the Section B: 3. Water section of the SEPA environmental checklist.

3a. Surface water

a. Surface

Describe and name, whenever possible, any onsite or nearby surface water body, including streams (permanent, intermittent, or seasonal), rivers, ponds, wetlands, lakes, salt water, etc. Although a distance has not been set by rule, a good rule of thumb for determining "nearby" is whether the site is within 300 feet of the ordinary high water mark or within the width of the floodplain whichever is larger.

1. Is there any surface waterbody on or in the immediate vicinity of the site?

Water bodies include year round and seasonal streams, saltwater, lakes, ponds, wetlands, domestic water intakes, or any forested or un-forested wetlands on the site, or downstream or down slope. Please identify possible fish-bearing streams. An intermittent stream might have fish present for a few weeks or months when stream flows are high.

Also note the presence of seeps, springs, wetlands or artificial water bodies. The site may appear dry but include areas that are transitional between open water and uplands. It may be periodically inundated or saturated.

Identify any water quality issues such as a Total Maximum Daily Load a locally-focused scientific study that calculates the pollution a water body can receive and still meet water quality standards. It provides information about existing conditions and a watershed's sensitivity to additional development impacts.

Describe any water-based invasive species in the area (e.g., water milfoil, New Zealand mud snails, yellow flag iris, Brazilian elodea) and steps taken to avoid their spread during the project.
 
2.  Will the project require any work over, in, or adjacent to (within 200 feet) the described waters?
  

Any part of the project, plan, or other proposal that impacts the a water body's shoreline is identified in this answer. Include grading, fill, or excavation; installation, construction, or demolition; paving; painting or maintenance activities; storage of materials; planting or removing vegetation; etc. if it will occur within 200 feet of the water and describe where the activities will take place in relation to the water body.  

You must identify the possibility of intentional or inadvertent filling of, or runoff to streams, wetlands or other water bodies. Attach plans (or preliminary schematic drawing with all water bodies included), if appropriate for the type of activity. If the project involves impacts to aquatics lands, you may need a hydraulic project approval (HPA) from the state Department of Fish and Wildlife, shoreline permits from the local government and possibly a use authorization from the Department of Natural Resources.  

Describe any water-based invasive species known to exist in the area (e.g., water milfoil, New Zealand mud snails, yellow flag iris, Brazilian elodea) and steps taken to avoid their spread during the project. Refer to the resources listed below for information:  

Describe any measures that will be taken to ensure that the equipment being used is not introducing or spreading invasive species. The Washington Invasive Species Council has developed prevention protocols to be used when working in or near water. For the removal or placement of in-water structures, describe how the material either to be removed or placed has been checked for invasive species and how any invasive species found will be removed and disposed of appropriately.
 
Additional Resources: 3. Estimate the amount of fill and dredge material that would be placed in or removed from the surface water or wetlands and indicate the area of the site that would be affected

Describe the quantity, type of material, and the location including the size of the area to be filled or dredged. Include the results of toxicity tests or other information about the fill or dredge material. Fill is any material that will change the bottom elevation of an aquatic area, wetland, or water body. Water bodies include year round and seasonal streams, saltwater, lakes, ponds, wetlands, domestic water intakes, or any forested or un-forested wetlands on the site or down stream/down slope.  

Example: Remove 4,000 cubic yards of silt and gravel from Big River to maintain navigational channel between river mile (RM) 3.5 and RM 6.2.  Results of toxicity tests are attached.  

Tip:  Also describe any measures that will be taken to ensure that the equipment being used is not introducing or spreading invasive species. The Washington Invasive Species Council has developed prevention protocols to be used when working in or near water. For the removal or placement of in-water structures, describe how the material either to be removed or placed has been checked for invasive species and how any invasive species found will be removed and disposed of appropriately.
 
4. Will the proposal require surface water withdrawals or diversions?

Describe the quantity and location of any surface water withdrawal or use even if for a non-consumptive use (meaning that the same quantity of water is returned to the waterbody). This includes temporary or long-term use. Diversions refer to changes in flow patterns, such as diverting a stream away from a building site or the creation of ponds or inlets.  Ecology regulates the withdrawal of water from surface and underground sources. A permit is not required if the withdrawal is less than 5,000 gallons per day for industrial or domestic use, or for stock watering. Any work that uses, diverts, obstructs, or changes the natural flow or bed of any fresh water or saltwater of the state may require a Hydraulic Project Approval from the Washington Department of Fish and Wildlife. For projects involving State-Owned Aquatic Lands, a use authorization from Department of Natural Resources may be needed.  

Also consider the connectivity between water bodies for situations of water diversion. Does diversion source contain invasive species that could spread to a new water body?

 Additional Resources: 5. Does the proposal lie within a 100-year floodplain?

Flood zones are geographic areas that the FEMA has defined according to varying levels of flood risk. These zones are depicted on a community's Flood Insurance Rate Map (FIRM) or Flood Hazard Boundary Map. Each zone reflects the severity or type of flooding in the area.
As applicable, identify the current designation for flood risk at the proposal site. This information is important and not limited to 100-year flood areas.

Additional Resources: 6. Does the proposal involve any discharge of waste materials into surface waters?

Include waste or contaminates associated with industrial wastewater; domestic sewerage; agricultural runoff; stormwater drainage from parking lots, equipment storage areas, chemically-treated lawns and landscaping; etc. Describe the source, the likely contaminates, and quantities if known.  
Waste materials means hot or very cold water, sediments, chemical by-products, wash water, sewage, stormwater and other pollutants.  

Discharge includes seeping or dripping of hot or very cold water; sediment filled water, controlled runoff, or liquid by-products of an activity, such as bore hole drilling waste products.

Water bodies include year round and seasonal streams, saltwater, lakes, ponds, wetlands, domestic water intakes, or any forested or un-forested wetlands on the site or downstream/down slope. Please identify possible fish bearing streams and note that an intermittent stream might have fish present for a few weeks or months of the year during periods of high flow.