Sussex County operates the following sewer and water districts:
- Angola Neck Sanitary Sewer District
- Bay View Estates Sanitary Sewer District
- Bethany Beach Sanitary Sewer District
- Blades Sanitary Sewer District
- Cedar Neck Expansion of the Bethany Beach Sanitary Sewer District
- Chapel Branch Area of the Sussex County Unified Sanitary Sewer District
- Dagsboro-Frankford Sanitary Sewer District
- Dewey Beach Sanitary Sewer District
- Dewey Beach Water District
- Ellendale Sanitary Sewer District
- Fenwick Island Sanitary Sewer District
- Henlopen Acres Sanitary Sewer District
- Herring Creek Sanitary Sewer District
- Holts Landing Sanitary Sewer District
- Johnsons Corner Sanitary Sewer District
- Long Neck Sanitary Sewer District
- Miller Creek Sanitary Sewer District
- Millville Expansion of the Bethany Beach Sanitary Sewer District
- Mulberry Knoll Area of the Sussex County Unified Sanitary Sewer District
- North Bethany Expansion of the Bethany Beach Sanitary Sewer District
- Oak Orchard Sanitary Sewer District
- Ocean View Expansion of the Bethany Beach Sanitary Sewer District
- Ocean Way Estates
- Sea Country Estates Sanitary Sewer District
- South Bethany Sanitary Sewer District
- South Ocean View Sanitary Sewer District
- Sussex Shores
- West Rehoboth Expansion of the Dewey Beach Sanitary Sewer District