---
title: price what the creek already does
canonical_url: https://ensurance.app/guide/price-what-the-creek-already-does
markdown_url: https://ensurance.app/guide/price-what-the-creek-already-does.md
subtitle: the half of a nature-based solutions cost benefit analysis a small town can write before the grant opens
category: how-to
---

# price what the creek already does

*the half of a nature-based solutions cost benefit analysis a small town can write before the grant opens*

A **nature-based solutions cost benefit analysis** compares what it costs to protect, restore or extend living ground with the losses and expenses that ground avoids. For a small town, the most useful version is the one that starts with what nature is already doing. The creek that carries the storm, the floodplain that takes the overflow, the woodlot that holds the slope. These are working today. The question is what the town would pay if they stopped.

This post is for the coordinator in a town that signed the Global Covenant of Mayors and now has a risk and vulnerability assessment to write, and for the regional helpdesk that supports them. It is about adding one column to that assessment: what the natural asset does for the town while it still works. We offer this work; we have not yet done it for a GCoM town, so the cases here are other people's.

The creek, the floodplain and the woodlot exist whether or not the town puts a number on them. The number is how they show up next to the culvert and the levee when the council compares options. It does not measure their worth, and it does not need to.

:::johnson
**the risk assessment prices the hazard. price the ground that holds it back.**

Most assessments say what could go wrong. Add what is already going right, in dollars, and the adaptation plan has another option to compare.

[read how the assessment becomes a parcel list →](/guide/a-risk-assessment-is-a-list-of-parcels?from=guide)
:::

## what the covenant asks a town to assess

Covenant signatories prepare a climate risk and vulnerability assessment: which hazards can reach the town, what is exposed, and how vulnerable it is. The adaptation plan builds on that assessment, and progress is reported over time. For a town with one coordinator, that is a lot of form.

[A risk assessment is a list of parcels](/guide/a-risk-assessment-is-a-list-of-parcels?from=guide) argues for turning a hazard table into named ground. This post adds the dollar figure that lets that ground compete in the plan.

## the two halves of the analysis

A cost benefit analysis for a nature-based solution has two halves. Most guidance only covers the first.

| | **the project half** | **the asset half** |
|---|---|---|
| Question | What does it cost to restore or extend the natural option, and what losses does it avoid? | What is the existing natural asset doing now, and what would it cost to lose it? |
| Example | Reconnecting a floodplain to the creek | The floodplain already connected, and the culvert you would need without it |
| Who asks | The grant program | The town, before anyone else does |
| What it protects | A new investment | An existing one |

The asset half can be drafted without a new design, because the asset exists and its work can be estimated from published values. It is also the half that stops a town from trading away a working floodplain for a parking lot without knowing the price.

## how a town runs the asset half

**Name the asset and the hazard.** "The floodplain meadow east of the bridge, which takes the creek's overflow before it reaches Main Street." One sentence.

**Estimate what it does in a year.** Use published values per acre per year for that kind of ground, adjusted for its condition. Match the land type first. A creek meadow is likely riparian or wetland ground, not a city park. In the United States, FEMA publishes per-acre values by land type for its own benefit-cost analysis. Each total is mostly non-flood value: of FEMA's $15,487 per acre per year for urban green open space, $316 is flood and stormwater and $7,010 is aesthetic. Use only the service that matches your hazard, and say which you used. Outside the United States, the Ecosystem Services Valuation Database (ESVD) pools published per-hectare studies by ecosystem and service.

**Estimate what replacing it would cost.** What would the town build if the meadow were gone? A detention basin, a bigger culvert, a raised road? The public works director usually has a rough number, or an old estimate on file. Gibsons, British Columbia, used this method on one asset, the stormwater ponds in White Tower Park, and the Municipal Natural Assets Initiative's case study put the engineered replacement at about $3.5–4 million (Canadian). Label it as what it is: a one-time capital cost, not a yearly value. And apply the test: replacement cost counts as a value only if the town would really build the replacement and it would give the same service. If not, call the number a ceiling.

**Name who depends on it.** The homes and businesses on Main Street. The county road. The school. These are the people who would pay for the replacement, through taxes, insurance or repairs, if the meadow failed. Name who is exposed, not only what is worth most. Replacement cost and property damage follow property value, so a creek that protects a lower-value block will look cheaper to lose than it is.

**Put it in the assessment.** Add a column to the hazard table: "the natural asset that reduces this hazard, the yearly value of the matching service, and the one-time cost to replace it." That one column changes what the adaptation plan considers.

## why the asset half matters for grants

In the United States, FEMA's benefit-cost toolkit can count ecosystem service benefits. Which benefits a given project may claim is set by FEMA's current guidance, so ask your state hazard mitigation officer. As in any benefit-cost analysis, a project is credited with what it changes, so the standing value of the meadow is not itself the claim. The asset half gives you the starting facts a project case needs: what the ground does, and what the town loses if it goes.

The history matters for how you file. A 2013 policy allowed ecosystem service benefits for acquisition projects that already met a benefit-cost ratio of 0.75 on traditional benefits. A 2016 clarification extended it to all project types under the same test. A 2020 policy dropped the test. FEMA lists that policy as archived as of March 2023, and the values sit in its toolkit resources, so read the current guidance or ask your state hazard mitigation officer before you rely on it.

A town that has named the asset and its dependents has the start of the project case written before the grant opens. Outside the United States, the method is the same even where the numbers come from different studies: the asset, its annual service, its replacement cost, its dependents.

## what not to do

**Do not add numbers from different books.** FEMA's per-acre values, its separate per-tree value for urban trees, and figures from other methods are separate instruments. Pick one and say which.

**Do not overclaim.** An estimate from published values is rough: the studies were done elsewhere, on other ground. Say so in the assessment. A reviewer trusts a stated range more than a precise figure with no basis.

**Do not stop at the town line.** The creek that floods Main Street may start in the next county. The forest that keeps it clean may be on a private ranch. Name those assets too. [Your city is upstream and downstream at once](/guide/your-city-is-upstream-and-downstream-at-once?from=guide) explains why.

**Do not dunk on the grey option.** Sometimes the culvert is the right answer. The analysis exists so the town can choose with both options on the table.

## who pays, once the number exists

A number in an assessment is a start, not a budget. Small towns rarely have the capacity to carry the cost of an asset on their own, and they do not have to. The dependents named in the analysis are the first people to ask: the county, the state transport agency that owns the road, the utility, the insurer that carries the town's flood book. [Who pays for a town's flood work, by the unit](/guide/who-pays-for-a-towns-flood-work-by-the-unit?from=guide) sets out those buyers. The [flood resilience](/flood-resilience.syndicate?from=guide) and [water cycle](/water-cycle.syndicate?from=guide) lines are live for this work, and a town can [ask us](/contact?from=guide&topic=city-nature-valuation) what joining one means today.

## frequently asked questions

### what is a nature-based solutions cost benefit analysis?

It compares the cost of protecting, restoring or creating living infrastructure, such as wetlands, floodplains or urban forest, with the benefits it delivers, such as avoided flood damage, lower stormwater costs or reduced heat illness. The benefits are often estimated from published ecosystem service values per acre per year.

### can a small town do this without a consultant?

The asset half, yes. It needs the acres, the condition, a published per-acre value, the cost of the engineered alternative, and a list of who depends on the asset. A town with a floodplain map and a public works director can draft it.

### does FEMA accept ecosystem service benefits?

Sometimes. FEMA's benefit-cost toolkit includes ecosystem service values, and FEMA policy since 2013 has allowed those benefits for certain projects, but the rules have changed and the 2020 policy is archived. Ask your state hazard mitigation officer which rules apply before you file.

### what if our town is outside the United States?

The method is the same. Use regional ecosystem service values where they exist (the ESVD is one place to look), and the cost of the engineered alternative from your own public works records. Your regional covenant may already have a recommended source.

## next steps

Pick the hazard your town fears most and the ground that holds it back. Write the one sentence, then the four numbers. If you would like every natural asset your town depends on valued together, the regional natural asset analysis is listed on [our services page](/services?from=guide#finance) with its price range. Regional helpdesks can [ask us about a cohort](/contact?from=guide&topic=city-nature-valuation).

## sources

- [Global Covenant of Mayors reporting framework guidance](https://www.globalcovenantofmayors.org/wp-content/uploads/2019/08/Data-TWG_Reporting-Framework_GUIDENCE-NOTE_FINAL.pdf): the risk and vulnerability assessment
- [ICLEI Oceania, GCoM reporting](https://icleioceania.org/global-covenant-of-mayors-for-climate-and-energy-temp/reporting/): the adaptation plan building on the assessment
- [FEMA, *Ecosystem Service Value Updates*](https://www.fema.gov/sites/default/files/documents/fema_ecosystem-service-value-updates_2025.pdf) (2022 values): per-acre values by land type
- [Ecosystem Services Valuation Database](https://www.esvd.info/): pooled per-hectare studies
- [FEMA, ecosystem service benefits policy archive](https://fema.gov/sites/default/files/documents/fema_ecosystem-service-benefits-policy-archive.pdf): policy history
- [MNAI, case study: White Tower Park ponds](https://naturalassetsinitiative.ca/documents/case-study-valuation-of-the-stormwater-management-services-in-whitetower-park-ponds/): replacement cost of $3.5–4 million

## the series

1. [how a city values the nature it already owns](/guide/how-a-city-values-the-nature-it-already-owns?from=guide)
2. [why a city should run an ecosystem service valuation](/guide/why-a-city-should-run-an-ecosystem-service-valuation?from=guide)
3. [how to build a natural asset inventory with the staff you have](/guide/how-to-build-a-natural-asset-inventory?from=guide)
4. [what a city's green space is worth, and what the number is for](/guide/what-a-citys-green-space-is-worth?from=guide)
5. **price what the creek already does** (you are here)
6. [your city is upstream and downstream at once](/guide/your-city-is-upstream-and-downstream-at-once?from=guide)
7. [hire a natural asset valuation for your city or town](/guide/hire-a-natural-asset-valuation-for-your-city?from=guide)