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Single Family ResidenceResidential
$494,185$340 / ft²
TopHap EstimateOur estimate of what this home would sell for today, based on nearby sales, the home's size and features, and local price trends. It is a starting point, not an appraisal.· confidence 95How well the pricing models agreed with each other on this home. Higher means the estimate rests on stronger, more consistent data.· as of Aug 30, 2026
Last sold for $345,000 on Jul 14, 2016

423 PORPOISE LN

RIVA, MD 21140
2
Baths
1,452 ft²
Living AreaTotal finished area of the structures, from county records. Some counties include shared space like hallways or a building gym, so it may not match a listing.
0.31 ac
Lot SizeThe size of the land the home sits on, from county records.
1970
Year BuiltThe year the home was originally built, according to county records.
1
StoriesHow many floors the home has above ground.

Valuation

$494K
$470K low$518K high
Last SaleThe most recent sale price and date from the recorded deed. Transfers between family members or companies may not reflect market value.$345,000 · Jul 14, 2016

Tax & Assessment

Property TaxThe property tax billed for this tax year. It usually pays for schools, roads, and local services.$4,490 (2025)
Assessed ValueThe value the county assigns to this home to calculate property tax. It is often lower than what the home would sell for.$411,900 (2026)
Assessed LandThe share of the county's assessed value that comes from the land itself, not the buildings.$239,100
Assessed ImprovementsThe share of the county's assessed value that comes from the buildings and other structures on the land.$172,800
Previous AssessedThe county's assessed value from the year before, useful for seeing how the assessment changed.$394,467
Assessor Market ValueThe county assessor's own opinion of market value. It is separate from our estimate and updates on the county's schedule.$411,900

Climate Risk

Overall riskThe average of the five hazard scores below, on a 0 to 100 scale. Higher means greater projected risk over the coming decades.16
57
FloodProjected flooding risk from rivers, heavy rain, and storm surge, scored 0 to 100. Higher is riskier.
15
WildfireProjected wildfire risk, scored 0 to 100, based on how much land burns in a typical year. Higher is riskier.
9
DroughtProjected water shortage risk, scored 0 to 100. Higher means more strain on the local water supply.
Projected Flood DepthHow deep a serious flood is expected to get here at some point in the next 30 years. Shown in inches.20 in
30-Year Flood ChanceThe chance of at least one serious flood here in the next 30 years, not in any single year.30%
FEMA Flood ZoneFEMA's flood zone for this address. Zones starting with A or V are high risk, and lenders usually require flood insurance there.minimal

Scores 0–100; higher = greater projected risk.

Property Facts

Property TypeThe broad category the county puts this property in, such as residential or commercial.Single Family Residence
StyleThe architectural style of the home, such as ranch or colonial.Split Foyer
CountyANNE ARUNDEL
Lot (acres)The size of the land the home sits on, from county records.0.32
RoofThe main material covering the roof, such as asphalt shingle or tile.Composition Shingle
HeatingThe type of heating system in the home.Yes
CoolingThe type of cooling or air conditioning in the home.Central
PoolWhether the property has a pool, and what kind, such as in-ground.No
FeaturesExtra features found in county records. Records are not complete everywhere, so a missing feature does not always mean the home lacks it.Deck · 64 ft²

Transaction History(3)

Sales and refinances filed with the county for this home. Not every transfer is a normal sale, so check the type before comparing prices.

Foreclosure Filings(1)

Assigned SchoolsThe public schools this address is zoned for. Boundaries change, so confirm with the district before you count on it.

E
Central Elementary SchoolB+
Elementary · Grades KG–5 · 2.2 mi
H
South River High SchoolA-
High · Grades 9–12 · 2.5 mi
M
Central Middle SchoolA-
Middle · Grades 6–8 · 2.7 mi

District: Anne Arundel County Public Schools

Neighborhood · ZIP 21140These are comparison scores, not percentages. 100 equals the national average, so 150 means about 50% above average.

CrimeLocal crime compared with the rest of the country, where 100 is average. It reflects things like population density, income, and how crime gets reported.106
Air pollutionOverall air pollution compared with the rest of the country, where 100 is average. Lower is cleaner.85
EarthquakeEarthquake risk and likely building damage compared with the rest of the country, where 100 is average. Scores can run far above 100.34

Index scale: 100 = US average (tick). Lower is better.

Homes occupiedThe share of homes here that someone lives in. The rest sit empty, including vacation and for-sale homes.96%
Bachelor's or higherThe share of adults 25 and older whose highest degree is a bachelor's degree.28%
Poverty rateThe share of people whose household income falls below the federal poverty line, which varies by family size.1.4%
UnemploymentThe share of men 16 and older who are out of work and actively looking. Only men are counted in this figure.0.8%
PopulationHow many people live in this area.2,741
DensityPeople per square mile. Higher numbers mean a more crowded, urban area.1,547 / mi²
Median incomeThe middle household income here — half of households earn more, half earn less.$138,675
Average incomeThe average household income. It runs higher than the median when a few high earners pull it up.$180,517
Average tempThe average temperature here across a full year.57°F
Annual precipHow much rain and melted snow falls here in a typical year.45 in
SunshineThe share of daylight hours that get direct sun in a typical year, counting cloud cover.57%

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Data by ATTOM. Valuations are automated estimates, not appraisals. Photos from Google Street View and may not depict the current property state.

How this home compares

423 Porpoise Ln measured against every home in its neighborhood, its ZIP code and its county, using county assessor records refreshed nightly. A home can stand out in one of those areas and look ordinary in another, because each one holds a different mix of homes.

  • Worth less than 79% of homes in Riva 21140
  • Costs more per square foot than 81% of homes in Anne Arundel County
  • Smaller than 81% of homes in Riva 21140
  • Has a bigger lot than 69% of homes in Anne Arundel County
  • Older than 71% of homes in Riva 21140

What homes are worth in Riva 21140

Each bar is how many homes fall in that price range. The marker is this home.

This home
$301K$1.6M

This home is worth more than 21% of homes in Riva 21140.

How it measures up in Riva 21140

The dot is this home. The mark in the middle is the typical home in Riva 21140.

Estimated value$494,185
CheaperTypical $653,777Pricier

Pricier than 21% of homes nearby

Price per ft²$340
CheaperTypical $303Pricier

Pricier than 75% of homes nearby

Living area1,452 ft²
SmallerTypical 2,226 ft²Bigger

Bigger than 19% of homes nearby

Lot size0.31 ac
SmallerTypical 0.28 acBigger

Bigger than 57% of homes nearby

Year built1970
OlderTypical 1979Newer

Newer than 29% of homes nearby

How 423 Porpoise Ln ranks against every home in each area.
MeasureThis homeRiva 21140Anne Arundel County
Estimated valuepricier than$494,18521% of homes50% of homes
Price per ft²pricier than$34075% of homes81% of homes
Living areabigger than1,452 ft²19% of homes27% of homes
Lot sizebigger than0.31 ac57% of homes69% of homes
Year builtnewer than197029% of homes32% of homes

About 423 Porpoise Ln

How much is 423 Porpoise Ln, Riva, MD worth?

The TopHap Estimate for 423 Porpoise Ln, Riva, MD is $494,185 as of Aug 30, 2026. The likely range is $470,278 to $518,092. The estimate is modelled from recorded sales, assessments and the property's own characteristics — it is not an appraisal.

When did 423 Porpoise Ln, Riva, MD last sell?

423 Porpoise Ln, Riva, MD last sold on Jul 14, 2016 for $345,000, according to the county's recorded deed. TopHap holds 3 recorded sales for this parcel.

How big is 423 Porpoise Ln, Riva, MD?

423 Porpoise Ln, Riva, MD has 2 bathrooms, 1,452 square feet of living space and a 0.32-acre lot.

When was 423 Porpoise Ln, Riva, MD built?

423 Porpoise Ln, Riva, MD was built in 1970, making it 56 years old. It is a split foyer home. The building has 1 story.

What schools serve 423 Porpoise Ln, Riva, MD?

423 Porpoise Ln, Riva, MD is assigned to Central Elementary School (elementary), rated B+; South River High School (high), rated A-; Central Middle School (middle), rated A-. All sit in Anne Arundel County Public Schools. Attendance boundaries change — confirm with the district before relying on an assignment.

How does 423 Porpoise Ln, Riva, MD compare to other homes in Riva 21140?

Among the 1,438 homes in Riva 21140, it is worth more than 21% of them ($494,185 against a typical $653,777), its price per square foot is higher than 75% of them ($340 against a typical $303), it is bigger than 19% of them (1,452 ft² against a typical 2,226 ft²), its lot is bigger than 57% of them (0.31 ac against a typical 0.28 ac) and it is newer than 29% of them (1970 against a typical 1979). Measured against all of Anne Arundel County, it is worth more than 50% of homes there. These shares are recounted nightly from the full county assessor record for each area, not from active listings.

What are the property taxes on 423 Porpoise Ln, Riva, MD?

The 2025 property tax bill for 423 Porpoise Ln, Riva, MD was $4,490. The county assessed it at $411,900.

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