Maintaining Docks on Tidal Creeks: Permits & Best Practices

Sunrise coffee, sunset fishing, and easy boat days all start at your dock. On Mount Pleasant’s tidal creeks, though, that dock sits in regulated waters with sensitive marsh. A simple repair can require approvals, and the wrong materials can shorten your dock’s life. This guide shows you the permits, size limits, and maintenance moves that help you stay compliant and protect your investment. Let’s dive in.

Permit basics in Mount Pleasant

You will usually need approvals from the state and the U.S. Army Corps of Engineers. Start early to confirm eligibility and avoid delays.

• State approval. Most work in coastal critical areas requires a Minor Critical Area Permit or may qualify under a general permit through SCDHEC’s Bureau of Coastal Management. Applications use ePermitting and must include stamped drawings by a South Carolina licensed surveyor, engineer, or landscape architect. Review the process on SCDHEC’s Critical Area Permitting page. (SCDHEC Critical Area Permitting)
• Federal review. The USACE Charleston District typically authorizes docks under Nationwide or Regional General Permits. Larger or nonstandard projects may need an Individual Permit. You can see the district’s permitting process and contact information online. (USACE Charleston Regulatory)
• Local references. The Town of Mount Pleasant provides Harbor Patrol contacts and watercraft rules that are helpful when planning repairs or mooring. (Town of Mount Pleasant Harbor and Anchoring)
• Resource maps. Before you plan work, check for nearby shellfish leases, oyster beds, or sensitive habitat that can limit design. (SCDNR resource maps)

Repair vs. rebuild: what needs a permit

If your dock was previously permitted and you will repair within the original size and configuration, you may be eligible for SCDHEC’s maintenance and repair acknowledgment rather than a new permit. Expansions, relocations, or major rebuilds typically require a new permit or amendment. Notify SCDHEC through ePermitting before you start so you know which pathway applies. (SCDHEC maintenance FAQ)

Dock size and siting rules to know

State rules limit dock size based on creek width and site conditions. These caps shape what you can build or replace.

• Creeks 10 feet wide or less: no docks allowed.
• Under 20 feet: usually no docks, with only rare exceptions.
• 20 to 50 feet: about 120 square feet waterward of the marsh critical line.
• 51 to 150 feet: about 160 square feet.
• Over 150 feet: about 600 square feet.

Eligibility also depends on whether your upland lot fronts navigable water within 1,000 feet, plus frontage and side offset rules. Some subdivisions use a Dock Master Plan that governs which lots can have docks. Confirm your parcel’s eligibility and any plan governing your street. (SCDHEC Critical Area Permitting)

Maintenance that lasts in tidal creeks

Inspect on a schedule

Look over your dock at least once a year and after major storms. Check for loose or corroded fasteners, split or soft timber, flotation damage, settlement, and broken decking. Photograph issues so you can track changes and share with your contractor or engineer.

Choose durable pilings

Marine borers target timber in brackish and salt water. For longer life, consider pre-stressed concrete, coated steel, or marine-grade composite pilings. If you use timber, specify aquatic-approved preservatives and consider encasements or wraps to limit borer access and leaching. Targeted pile replacement can extend life without a full rebuild. (Marine borer overview)

Use corrosion-smart hardware

Install 316 stainless or hot-dip galvanized fasteners and connectors sized for marine exposure. Avoid mixing metals that can cause galvanic corrosion. Replace rusted hardware promptly to prevent loosened connections and racking.

Reduce shading over marsh

Chronic shade can weaken marsh and submerged aquatic vegetation. Keep dock width to the minimum needed, raise deck elevation where feasible, and use grated or light-transmitting decking over shallow marsh. Limit roofed or covered structures and orient the walkway to reduce all-day shade when you can. These steps also help permitting. (Dock shading guidance)

Prevent pollution during work

Do painting, sealing, and pressure washing upland whenever possible. Contain debris and dispose of it properly. Use only materials approved for aquatic use and avoid toxic preservatives in new or replacement members. These best practices protect water quality during upkeep. (BMP reference)

Storm prep and records

Before storm season, secure or remove loose items and small floats. After a storm, document damage with photos and measurements. Contact SCDHEC to confirm whether your plan qualifies as maintenance-only before replacing or enlarging structures. Keep copies of permits, approved drawings, and any maintenance acknowledgment letters for future work or when you sell. (SCDHEC forms and transfers)

Bring in licensed pros

Hire a marine or structural engineer or a licensed dock contractor if you see pile rot, settlement, or structural distress. You will need stamped drawings to apply for permits. A licensed surveyor can confirm the marsh critical line and measure creek width for sizing rules. (SCDHEC Critical Area Permitting)

Timeline, fees, and what to expect

• State process. After SCDHEC receives a complete minor permit application, the agency typically runs a 15-day public notice for new critical area permits. Minor permit fees for private docks often range from about 100 to 250 dollars. Major permits cost more. Exact fees depend on size and type. (SCDHEC fees and process)
• Federal process. If your project fits a Nationwide or Regional General Permit and does not trigger pre-construction notification, review can be faster. Individual Permits can take many months due to coordination. Contact the Charleston District early to confirm your path. (USACE Charleston Regulatory)

Professional drawings can cost several hundred to several thousand dollars depending on complexity. Construction and repair costs vary with access, materials, and equipment like boat lifts.

Quick homeowner checklist

• Confirm eligibility with SCDHEC and ask if a Dock Master Plan applies to your subdivision.
• Pull prior permits and approved drawings from your records.
• Walk your dock and document needs with photos and notes.
• Call licensed pros for a condition assessment and stamped drawings if needed.
• Choose durable materials and grated decking to reduce shading.
• Plan upland work areas and debris containment before starting.
• Notify SCDHEC about maintenance vs. new work and coordinate with USACE.
• Keep all approvals and letters for future maintenance and resale.

Protecting tidal creeks is good stewardship and smart ownership. With the right permits and maintenance plan, your dock will serve you well through many seasons on the water. If you are weighing a repair, rebuild, or a new home on a tidal creek, reach out to Anna Gruenloh for calm, informed guidance on waterfront living in The Burbs and beyond.

FAQs

Do Mount Pleasant dock repairs need permits?

• If you keep repairs to the original size and layout of a previously permitted dock, you may qualify for SCDHEC’s maintenance acknowledgment instead of a new permit. Expansions or major rebuilds usually require a new permit. (SCDHEC maintenance FAQ)

How does creek width limit my dock?

• South Carolina caps size based on creek width. For example, 20 to 50 feet wide is about 120 square feet waterward of the critical line, and over 150 feet is about 600 square feet. Very narrow creeks often do not allow docks. (SCDHEC dock sizing rules)

Who do I contact to start the process?

• Begin with SCDHEC’s Bureau of Coastal Management, then contact the USACE Charleston District for federal concurrence. Check Town of Mount Pleasant Harbor Patrol information for local rules and mooring. (SCDHEC) (USACE Charleston) (Town Harbor info)

What materials help my dock last longer in tidal creeks?

• Consider concrete, coated steel, or composite pilings to resist marine borers, use 316 stainless or hot-dip galvanized hardware, and choose grated decking to reduce shading and moisture. Keep painting and washing upland to protect water quality. (Marine borer overview) (Dock shading guidance)