By Josh McKnight | The McKnight Team
Delaware County council approved the purchase of 70 AWARE flood gauges for $332,119, funded with $107,845 in Community Development Block Grants and $224,274 in Local Share Account grants. The gauges track data and may eventually provide early warning detection for communities.
Delaware County flood risk is now mapped in a way it was not before. The county planning department has identified 230 flood problem areas, including 130 flagged as high priority, across its 49 municipalities.
How the County Actually Got These Numbers
The Pennsylvania Department of Environmental Protection requires every county to develop an Act 167 Stormwater Management Plan that accounts for extreme events, and to revise it every five years. Delaware County’s planning department built its list of problem areas by examining flood data and coordinating directly with all 49 municipalities. Gauge placement was recommended by Jacobs Engineering, the consultant on that countywide plan.
That process is why the 230 figure is worth more than a general warning about weather. It is not a projection. It is a list of specific locations that have already flooded, assembled municipality by municipality. Regional climate specialists describe flooding as the most common hazard in Greater Philadelphia, driven by aging and undersized stormwater systems, dense development and limited municipal budgets rather than by rainfall alone.
What Delaware County Flood Risk Actually Does to a Sale
Buyers think about flooding as a disaster question. Underwriters think about it as a monthly payment question, and that is the version that shows up at your closing table. A flood determination changes the insurance line. The insurance line changes the debt to income ratio. The ratio changes what a buyer can pay for your house.
Set that against what the numbers show right now. The typical Delaware County home value is $369,653, up 2.3 percent over the past year, and the county median sale price was $302,250 in April, per Zillow data through May 31, 2026. Homes went to pending in about seven days. There were 1,197 homes for sale across the county.
A seven day market forgives almost everything. It does not forgive a surprise at the appraisal.
Why 130 High Priority Areas Is the Number to Watch
The county did not just count problem spots. It ranked them, and 130 of the 230 carry a high priority designation. That subset is where public money and public attention will concentrate over the next several years, which cuts in two directions for the owners inside those areas.
On one hand, a high priority designation attracts mitigation funding, and infrastructure that actually gets fixed makes a street more valuable over time rather than less. On the other, designations tend to become public record, and public record eventually reaches disclosure forms and pricing conversations. Both effects are real, and which one dominates depends heavily on how quickly the work gets funded. Reasonable people are going to disagree about that for years.
What is not ambiguous is the value of knowing before somebody else tells you. An owner who understands their own stormwater situation can address it on their timeline, document the fix, and price accordingly. An owner who finds out during an inspection contingency is negotiating from behind. If you know somebody in Delaware County who has watched water pool in the same spot every spring, that is worth mentioning to them.
What This Means for You
If you own in Delaware County, find out whether your parcel sits in one of the identified areas and whether your municipality has a stormwater project planned. If you have had water intrusion, document what you did about it, because a repaired and documented issue prices far better than an undisclosed one. If you are buying, order the flood determination early rather than at the end, and get an insurance quote before your contingency period closes rather than after.
Stormwater is one of those variables that never appears in an online estimate and shows up anyway at settlement. Our Media market page covers a Delaware County market where these questions come up regularly, which is a useful reference point when you are weighing a specific street against a specific price.
Thinking about buying or selling in Delaware County? Let’s talk.
Frequently Asked Questions About Delaware County Flood Risk
How do I find out if my home is in a flood problem area?
Start with your municipality, since the county built its list of 230 areas by coordinating with all 49 of them. Your township or borough office can tell you whether your parcel appears and whether any project is planned.
Does flooding history hurt my resale value?
A documented and repaired issue prices far better than one a buyer discovers during inspection. The larger risk is not the water itself. It is the surprise, which hands the advantage to the other side of the table.
Will flood insurance cost more in these areas?
Insurance is priced on the flood determination for your specific parcel, not on the county list. Get a quote during your contingency period rather than after, because that premium affects what a lender will approve.
What happens next with the 70 flood gauges?
They will be placed at locations recommended by the county’s Act 167 stormwater consultant and will track data, with the eventual goal of early warning detection. The county must revise that stormwater plan every five years.
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