City of Mercer Island, Washington - Home City of Mercer Island, Washington - Home Facebook Twitter YouTube
advanced search | site map
HOME City Council DEPARTMENTS BOARDS & COMMISSIONS CONTACT US
Back
LINE
Development Services - Building & Planning
LINE
Public Works
LINE
*
Notify me by Email
FAQs - Development Services - Building & Planning
Docks on Waterfront Lots

Q: Can I build a dock on my waterfront lot?

A: One dock is permitted on any waterfront lot developed with a single family residence as an accessory to the dwelling if the lot has a minimum water frontage of 40 feet, provided it can meet all setback requirements from adjoining moorage facilities and lateral property lines.


Back to top
Top

Q: What is a moorage facility?

A: A moorage facility is any device or structure used to secure a boat or a vessel, including piers, docks, piles, lift stations or buoys.


Back to top
Top

Q: What is covered moorage?

A: A pier, dock, boatlift, series of piles, or other structure intended for moorage over which a roof or canopy is erected.


Back to top
Top

Q: How far into Lake Washington can my moorage facility, covered moorage, lift station or floating platform extend?

A: The maximum length or distance waterward from the Ordinary High Water Mark (OHWM) is 100 feet, but in cases where the water’s depth is less than 10 feet from the mean low water, the length may extend up to 150 feet or to the point where water depth is 10 feet at mean low water, whichever is less.


Back to top
Top

Q: What is the Ordinary High Water Mark (OHWM)?

A: OHWM stands for the Ordinary High Water Mark and is some times written as OHW. This line is usually identified by examining the bed and banks of the water along the shore to determine where action of the water has created a distinct mark upon the soil with respect to upland vegetation. If there are any questions at all, regarding the location of the OHWM, contact the Washington Department of Fish and Wildlife for assistance.


For more information, contact Washington Department of Fish & Wildlife at 425.649.4370.


Back to top
Top

Q: How wide can my dock be?

A: The maximum width is 8 feet.


Back to top
Top

Q: Is there a height limit for my dock?

A: Yes, piers and docks shall not extend more than 5 feet above the elevation of the OHWM.


Back to top
Top

Q: Does that height limit for my dock include handrails, walls or storage containers located on my dock?

A: No, walls, handrails and storage containers located on a dock or pier may extend up to 3 feet above the decking of the moorage facility.


Back to top
Top

Q: Is there a height limit for mooring piles?

A: Yes, the maximum height of a mooring pile is 10 feet above the elevation of the OHWM.


Back to top
Top

Q: Can I have a diving board or platform on my moorage facility?

A: Yes, provided they are no higher than 10 feet above the elevation of the OHWM.


Back to top
Top

Q: What type of shoreline permits will I need from the City to construct a new moorage facility?

A: Construction of a dock, designed for pleasure craft only, for the private noncommercial use of the owners, lessee, or contract purchaser of a single family dwelling, for which the cost or fair market value, whichever is higher, does not exceed $10,000, requires a Shoreline Exemption Permit and SEPA determination. If the cost of constructing the dock exceeds $10,000, then a Substantial Development Permit (SDP) and SEPA determination are required.


Back to top
Top

Q: What type of shoreline permits will I need from the City for covered moorage?

A: If the covered moorage will be placed on an existing dock and the total cost or fair market value, whichever is higher, of the covered moorage does not exceed $2,500 a Shoreline Exemption Permit is required. If the cost exceeds $2,500 a Substantial Development permit and SEPA determination is required.


Back to top
Top

Q: What if I have an existing dock and want to do some repairs to it?

A: Normal maintenance or repair of existing structures requires a Shoreline Exemption Permit. “Normal maintenance” includes those usual acts established to prevent a decline, lapse or cessation from a lawfully established condition. “Normal repair” means to restore a development to a state comparable to its original condition within a reasonable period after decay or partial destruction except where repair involves total replacement which is not common practice or causes substantial adverse effects to the shoreline resource or environment.


Back to top
Top

Q: Will I need a building permit for construction of a dock or covered moorage?

A: Yes, you must apply for a building permit to perform work on your dock. Click here to go to our Building Permits page.


Back to top
Top

Q: How do I know if other permits may be required?

A: The Department of Ecology maintains a Permit Assistance Center to provide statewide environmental permit information. By calling (360)407-7037, you can find out which environmental permits are required for your proposed activity.


Back to top
Top

Q: What are the setbacks for moorage facilities, covered moorage, lift stations, or floating platforms?

A: (1) A minimum of 35-foot setback from any adjoining moorage structure.
(2) A minimum of 10-foot setback from the lateral lines (the property line extended waterward.)


Back to top
Top

Q: Can I build a covered moorage?

A: Yes, covered moorage is permitted in association with single family residential lots, subject to the following:

  1. The maximum height of the covered moorage above the OHWM is 20 feet.
  2. The maximum area of the covered moorage is 600 square feet.
  3. Any covered moorage shall have open sides and may not be enclosed.
  4. There are specific location requirements for covered moorage, please refer to the City’s Shoreline Master Program for more detailed information related to the triangular area where covered moorage is permitted.
Area of Permitted Covered Moorage on Individual Lots

Covered moorage is prohibited in semi-private recreational tracts, commercial and noncommercial recreational areas.



Back to top
Top

Q: Are there state permits that I need to get to construct a dock or covered moorage?

A: Yes, state law requires that any person, organization, or government agency wishing to conduct any construction activity in or near state waters must do so under the terms of a permit (called the Hydraulic Project Approval-HPA) issued by the Washington State Department of Fish and Wildlife. State waters include all marine waters and fresh waters of the state, such as Lake Washington.

The law's purpose is to see that needed construction is done in a manner to prevent damage to the state's fish, shellfish, and their habitat. By applying for and following the provisions of the HPA issued under RCW 75.20.100-160, most construction activities around water can be allowed with little or no adverse impact on fish or shellfish.

The major types of activities in freshwater requiring an HPA include, but are not limited to: streambank protection; construction of piers and docks; covered moorage, pile driving; channel change or realignment; conduit (pipeline) crossing; culvert installation; dredging; gravel removal; pond construction; placement of outfall structures; or debris removal; and installation or maintenance (with equipment) of water diversions.

There is no charge for the HPA.



For more information, contact Fish and Wildlife Ofiice at 425.649.7042.


Back to top
Top

Q: Will I need a federal permit to construct a dock or covered moorage?

A: A U.S. Army Corps of Engineers (Corps) permit is required for certain activities near or in Lake Washington (waterward of the line of mean high or higher high water or ordinary high water) including wetlands. These activities include:

  • construction or installation of marinas, piers, wharves, floats, overhanging decks, boat lifts, jet ski lifts, intake pipes, outfall pipes, piling, bulkheads, boat ramps, marine railways, dolphins, overhead transmission lines, buoys, etc.
  • dredging in navigable waters of the United States.
  • the discharge of dredged or fill material into the water or wetlands; grading or mechanized land clearing of wetlands; ditch sidecasting in wetlands; soil movement during vegetation clearing in wetlands; groins, breakwaters, road fills, beach enhancement, riprap, jetties, etc., in waters or wetlands.
Endangered Species Act Guidance for new and replacement piers and bulkheads in Lake Washington
In order to protect threatened species in the Lake Washington freshwater system, the Corps of Engineers (Corps), the National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife Service (FWS) have developed Endangered Species Act (ESA) Guidance for applicants proposing new and replacement piers, bulkheads, and other activities. This Guidance is provided to assist applicants, expedite project review, and streamline the permit process while preserving protected species. This Guidance will help applicants avoid impacts to protected species by incorporating impact reduction and habitat enhancement measures into their project design and construction.

Please contact the local office of the US Army Corps directly for specific information regarding federal permit application and approval:
 

U.S. Army Corps of Engineers, Seattle District
Regulatory Branch, Post Office Box 3755, Seattle, Washington 98124
PHONE:(206) 764-3495
FAX: (206) 764-6602


Back to top
Top
 

City of Mercer Island Washington | All Rights Reserved © 2017| Privacy Policy | printer friendly version Printer friendly version | Site by ProjectA.com