Mitigation market analysisPotomac River Watershed
The Potomac River basin drains about 14,700 square miles across West Virginia, Virginia, Maryland, Pennsylvania, and the District of Columbia. From the Allegheny highlands its North and South Branches join, and the river flows past Washington, D.C., into the Chesapeake Bay. This HUC-6 basin lies in District of Columbia, Maryland, Pennsylvania, Virginia, and West Virginia. 91 commercial mitigation banks can sell credits into this watershed — 28 of them sited inside it — and it recorded 237 credit sales in 2025.
Figures mirrored from USACE RIBITS · synced
020700 Watershed boundary
Deep species supply, tight stream
At the five-year average sales rate this watershed holds roughly 168.1 years of species credits, 20.3 years of mixed credits, 3.5 years of wetland credits, but only 2.4 years of stream credits. New species capacity would compete against a well-stocked shelf; stream is where supply is consumed closest to the rate it is created.
66,001.6078 credits/yr sold · 5-yr avg
79.3056 credits/yr sold · 5-yr avg
0.1521 credits/yr sold · 5-yr avg
5.25 credits/yr sold · 5-yr avg
Credits available to this watershed
Supply not yet on the shelf
91 commercial mitigation banks can sell into this watershed today and 28 are based inside it. The full directory — availability, credit classes and service areas — is on the Virginia page.
Browse Virginia mitigation banksNearby and comparable watersheds
Potomac River credit market — common questions
How many mitigation banks serve the Potomac River watershed?
91 commercial mitigation banks can sell credits into this basin today, and 28 of them are sited inside it. The remainder reach in from adjoining service areas. Banks that cannot sell — sold out, suspended, terminated, withdrawn, closed out, or still in review — are not in that count; the 10 still in review are counted separately as pipeline.
Is this a good place to develop a new bank?
It depends on the credit class. At the five-year average sales rate the watershed holds about 2.4 years of stream supply and 3.5 years of wetland supply and 20.3 years of mixed supply and 168.1 years of species supply, so the shorter runway is where capacity turns over fastest.
Why is this market ranked #6?
It is ordered on sales in reach, and it qualifies for the board because it also ranks nationally on sales generated here. Two measures are counted, both plain counts of commercial withdrawal transactions in the RIBITS ledger over the last ten complete calendar years (2016–2025), and neither is ever blended into the other. Sales in reach counts a sale toward every watershed the selling bank's service area covers — 2,268 here, #6 in the country. Sales generated here counts it toward the one watershed the selling bank sits in — 1,165 here, #2. Ranking uses sale counts rather than credit volume because credit units differ by class and cannot be summed, and in-lieu fee withdrawals are excluded throughout: an ILF program is a single counterparty however many sites it holds. The second measure is a floor rather than a tiebreak: a watershed can be in reach of heavy trade simply because the Corps drew wide service areas around it, and requiring both keeps that from reading as a market.
Order this watershed's report — or any other
Runway by credit class, supply bank by bank, the banks that can serve from outside it, pending entrants, and demand from the federal ledger — for one HUC-8 subbasin.
About the data on this page
Single-client banks are excluded from supply figures. Credit balances count only banks that can sell today — sold-out, suspended, terminated, withdrawn, closed-out and not-yet-approved banks are left out. In-lieu fee sites are left out of these figures. They are a separate product, second in the Corps’ preference order, and a program is one counterparty however many sites it holds. Credit classes offset different resources and are never added together. Totals across many banks are rounded to whole credits — a single bank’s own balance never is. What we call a “credit sale” is a credit withdrawal — the entry written in the federal credit ledger when credits are committed to a permit. At commercial banks a withdrawal generally represents a sale; at a single-client bank it offsets the sponsor’s own project. The figures count ledger transactions, not distinct purchases — one purchase may produce several withdrawals — and we count entries rather than credits moved, because credit classes are different units and cannot be added together. Sales are counted from the withdrawals in RIBITS’s own credit ledger over the last 10 complete years. They are counts of transactions, never sums of credits, for the same reason totals are kept per class. Each bar in a sales chart counts the credit sales recorded in that calendar year — withdrawals from the federal ledger, not quantities of credits. The final bar is the year in progress and is shown in a different color. No bars means no sales in those years.
Two counts appear on this page, and the second is part of the first. Banks that can sell here counts every commercial bank whose approved service area covers this basin and that has credits to sell today — what a buyer standing here can actually reach. One bank can serve several basins, so its sales count toward each. Banks based here counts how many of those same banks also sit inside the basin. Because the second is a subset of the first, they are never added together. Availability, runway and pace all describe the first count. The ranking is a separate measure: basins are ordered by ten years of sales made by the banks that can sell into them, and a basin only takes a place on the board if it also ranks nationally on the sales its own banks generated. Watershed groupings come from each bank’s service area intersected with the USGS Watershed Boundary Dataset. We group at the HUC-6 level because it is the scale at which these patterns are legible: a HUC-8 is sub-regional and usually too small, while a HUC-4 is large enough to average away the local dynamics that decide whether credits are available where you need them. Those links are refreshed monthly rather than nightly, because service areas and watershed boundaries don’t change frequently. The basin description, and the decision to give this basin a page at all, are ours. That selection is reviewed annually. A watershed makes the ranked board only if it has high sales by both measures we compute — sales in reach of it, and sales generated by the banks sited inside it. Runway is available credits divided by the average annual sales pace over five complete years, per class. It assumes today’s pace continues and no new bank opens — it is an arithmetic ratio, not a forecast.
The map on this page is drawn live from the EPA NEPAssist RIBITS MapServer when you load it.