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Heritage Complex
2662 Riva Road
Annapolis, MD. 21401
(410) 222-7500



Department of Public Works - Stormwater Management Fee 

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Watershed Protection and Restoration Fee 

Residential Propety Owners

Annual Residential WPRF Rates
Zoning Rate CalculationPhase In Yr 1Phase In  Yr 2Full WPRF 
R10One (1) ERU x 0.4$20.40$27.20$34
R15One (1) ERU x 0.4$20.40$27.20$34
R22One (1) ERU x 0.4$20.40$27.20$34
R1One (1) ERU $51$68$85
R2One (1) ERU$51$68$85
R5One (1) ERU$51$68$85
RAOne (1) ERU x 2$102$136$170
RLDOne (1) ERU x 2$102$136$170
  • The residential property owner charge is determined by a property’s estimated amount of impervious surface area.   
  • An Equivalent Residential Unit (ERU) of 2,940 square feet represents the median amount of imperviousness for properties in residential zones 1, 2 and 5.  
  • An ERU is the base unit for calculating the annual charge.  
  • Base annual rate for one (ERU) is $85.  
  • Properties are divided into separate billing tiers and represent zoning districts with an estimated imperviousness that is less than, equal to or greater than the base ERU of 2,940 square feet.
  • Recently approved legislative amendments provides an initial  60% phase (Fiscal Year 2014) and 80% for the year two (Fiscal Year 2015).  

Questions about the WPRF?  Please email DPW.

Non-Residential Propety Owners

Non-residenital charges based on the actual impervious surface area for individual parcels of land.  The property owner is billed the base rate of $85 for each ERU (2,940 square feet)
ERU                  =    2,940 sq. ft. of imperviousness
BASE RATE      =    $85 per ERU per year

Property with 30,060 sq. ft. of imperviousness is billed 10 ERUs x $85 RATE for $850.

  • Generally, non-residential fees are capped at 25% of their nominal State and County real property tax assessement prior to any tax credits, deferrals or exemptions.   
  • Non-residential fees greater than $500 phased in at 60% of assessment in year one and 80% in year two. 

WPRF-Property Tax Bill Charge Code and Fee Calculations

Billing CategoryTax Bill AppearanceFee Calculation
Residential Property Zoned RA, RLDSTORMWATER/WPRF-Tier 1$170 (2 x Base Rate)  
Residential Property Zoned R1, R2, R5STORMWATER/WPRF-Tier 2$85 (Base Rate)  
Residential Property Zoned R10, R15, R22STORMWATER/WPRF-Tier 3$34 (0.04 x Base Rate) 
Farm PropertySTORMWATER/WPRF-Farm$34 (0.04 x Base Rate)
Mobile Home ParkSTORMWATER/WPRF-MOBILE HOMENo. Of Spaces x 0.40 x Base Rate
Non-Residential Property (Religious Org)STORMWATER/WPRF-RELIG ORG$1 Flat
Private Academic SchoolSTORMWATER/WPRF-PVT SCH$170 (2 x Base Rate)
Private Road not owned by HOASTORMWATER/WPRF-PVT ROAD$85 (Base Rate)
Private AirportSTORMWATER/WPRF-PVT AIRPORT$170 (2 x Base Rate)
Standard Marina (–7.5 acres impervious)STORMWATER/WPRF-MARINA STDERU x Base Rate

Large Marina (+7.5 acres impervious)


1st 7.5 impervious acres = ERU x Base Rate

Impervious acres >7.5 = ERU x .25 x Base Rate

Non-Residential Charitable OrganizationSTORMWATER/WPRF-CHAR NONRESERU x Base x 0.51412
Homeonwer's AssociationSTORMWATER/WPRF-HOAERUxBR *not to exceed # of properties x $34
Multifamily DwellingSTORMWATER/WPRF-MULTI FAMILYERU x Base Rate x 0.4
Garden/High Rise Residential CondoSTORMWATER/WPRF-RES CONDOERU x Base Rate x 0.4 / # of units
Residential Property in Non-Res ZoneSTORMWATER/WPRF-RES IN NRZNERU x Base Rate
Non-Residential Property - GeneralSTORMWATER/WPRF-NON RESERU x Base Rate


Anne Arundel County, MD. 44 Calvert Street Annapolis, MD. 21401 | Telephone: (410) 222-7000 | Suggestions | Disclaimer

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