--- title: what is a serviceshed canonical_url: https://ensurance.app/guide/what-is-a-serviceshed markdown_url: https://ensurance.app/guide/what-is-a-serviceshed.md subtitle: the map of everyone who stands on one parcel category: ecosystem-services --- # what is a serviceshed *the map of everyone who stands on one parcel* A **serviceshed** is the area over which a piece of land delivers an ecosystem service, together with the people and built assets inside that area. For water, a parcel's serviceshed is everything downstream of it, to the last intake and floodplain. Read from an intake, the same idea is the watershed above it; the word is used both ways, and this series reads it from the parcel. A hedgerow's pollination serviceshed is the fields within a few kilometers. A forest's shade serviceshed is a couple of hundred meters of the land beside it. Draw the shed and you have drawn, in one shape per service, everyone who stands on that parcel. The parcel at the source of the shed is a living thing: a headwater forest above a hospital, a utility intake, a rail line, and a valley of farms. It exists whether or not anyone pays for it. [**Ensurance**](/?from=guide) is how the parcels that stand on it can pay it. It is not the forest. When one parcel sits at the source of many sheds at once, it is a [keystone parcel](/guide/what-is-a-keystone-parcel?from=guide). :::johnson **the serviceshed is the payor list.** — Everyone inside the shed receives the service. Overlapping sheds show who could share the cost of keeping it. [explore the places in the field →](/explore?from=guide) ::: ## one parcel, many sheds A single parcel usually sits at the top of several sheds at once, each a different shape, each holding different people. | service | the shape of the shed | who is inside it | |---|---|---| | Water quality and timing | The watershed below, to every intake and floodplain | Utilities, towns, irrigators, bridges, a hospital's cooling plant | | Flood storage | The floodplain and the channel downstream of the wetland | Homeowners, the county road, the rail embankment, and the policies on all three | | Pollination | A ring of 600 meters to 3 kilometers around the habitat | Orchards, seed growers, a berry farm | | Pest control | 100 meters to 5 kilometers, by what the predators eat | Row crops, vineyards | | Shade and cooling | 50 to 200 meters off the forest edge | The neighboring stand, a feedlot, a schoolyard | | Fire buffering | 100 meters to a kilometer, by the fuel | The subdivision, the transmission line, the utility that owns it | | Clean air | The airshed downwind, sometimes another country | Everyone who breathes; [air quality is made upstream](/guide/air-quality-is-made-upstream?from=guide) | | Rain | The precipitationshed, far downwind and often across borders | Rainfed farms and reservoirs; [the next water treaty may be a precipitationshed](/guide/the-next-water-treaty-may-be-a-precipitationshed?from=guide) | The distances are typical ranges from Jay Gutierrez's synthesis of seven mechanism families, used in [does protecting one parcel help the land around it](/guide/does-protecting-one-parcel-help-the-land-around-it?from=guide); none is exact. Water is the odd one: it follows the channel instead of fading in a ring, so a headwater parcel's shed can run the length of a river basin, though its share shrinks as other streams join. The last two rows are landscape-scale; one parcel's share of an airshed or a precipitationshed is small and rarely measurable. ## it runs both ways Start from the parcel and trace outward, and the shed shows everyone who benefits. Start from a building and trace inward, and the same geometry shows which parcels it depends on. [The dependency your map can't see](/guide/the-dependency-your-map-cant-see?from=guide) lays out those two directions, and [your place depends on a place](/guide/your-place-depends-on-a-place?from=guide) walks a hospital, a ski resort, and a power line through the inward trace. This page borrows the frame and does not rebuild it. If you have run a TNFD LEAP, the inward trace is the Locate step; the serviceshed is the same map read from the land's side, showing who else sits on your dependency. For an insurer, a flood shed is the set of insured exposures whose modeled loss would change if the wetland's storage were lost. Today that is a screen, not a pricing input. What the serviceshed adds to that frame is a boundary for each service. Lay the boundaries for water, flood, pollination, and fire on top of each other and one forest sits under all of them: the hospital, the county road crew, the orchard, the transmission line. The parties inside two or more sheds are the **co-payor list** those two posts point to: the named parties who each have their own reason to want the forest in good condition, and who could split the cost of keeping it there. Nobody carries a keystone parcel alone, and nobody has to. New York City is the familiar case. Since the 1997 watershed agreement, its Catskill and Delaware supplies have run without a filtration plant, paid for by the city's water ratepayers through one bill. That is millions of beneficiaries pooled through one utility, not the whole shed: others downstream still pay nothing. [What is the beneficiary pays principle](/guide/what-is-the-beneficiary-pays-principle?from=guide) has the figures and the history. ## what a serviceshed cannot tell you A shed is a screen, not a contract. Three limits are worth stating. **Size is not dependence.** A large shed with many households in it may depend lightly on the parcel; a small one with one intake may depend on it completely. The shed tells you who is inside. Dependence has to be read case by case: what breaks, how fast, and what the substitute costs. **Evidence is uneven by service.** Water and pollination sheds rest on strong results. A pest-control shed rests on evidence that is inconsistent from one landscape to the next. Draw it, and say which kind it is. A shed can carry harm too: a protected stand with heavy fuel can carry a fire run into the subdivision, and a patch can host the pest as well as the predator. Draw that shed with the same care. **Being inside the shed is not a promise to pay.** The people on the list receive the service today for nothing and can keep doing so. [The free rider is standing on a keystone parcel](/guide/the-free-rider-is-standing-on-a-keystone-parcel?from=guide) takes up what changes that. The shed only makes the list legible. ## the three questions we ask of a property Inside our own shop, we can ask the same three questions of any property we hold a record for, answered from the records we already have. 1. **What does this place need, and which stored parcels provide it?** The inward trace: what this place draws on. 2. **Which stored parcels does this one depend on, and which depend on it?** Both directions, parcel to parcel. 3. **Who already depends on it, so who do we call?** The people and organizations inside the shed, as far as our records go. A missing answer is a hole with a next step, not a guess. Water uses the stored basin chain, one basin up and one down. A relation is counted only when its own words say which way it points. A parcel inside this one is not a dependency. It is an admin tool that runs on one stored property at a time. We do not sell the graph. When a record allows, a property's public card shows the answers. The public door is [explore](/explore?from=guide). ## frequently asked questions ### what is a serviceshed? A serviceshed is the area over which a natural asset delivers a specific ecosystem service, plus the people and built assets inside that area. It does for each service what a watershed does for water, with the direction reversed. ### how is a serviceshed different from a watershed? A watershed is drawn upstream of a point; a parcel's water serviceshed runs downstream from it. Pollination, shade, and fire sheds are rings, not basins, and a parcel also sits in an airshed and a precipitationshed, each a different shape and size. ### who is in a serviceshed? Whoever receives the service: a utility and its ratepayers for water, farms for pollination, a subdivision and its insurer for fire buffering, a city for clean air. Overlapping sheds from different services identify the parties who could share the cost of protecting the source. ### can you map a serviceshed with public data? For water, yes, with basin and stream datasets. For pollination, microclimate, and fire, you can draw a reasonable ring from published reach distances. [How to find the keystone parcels in a watershed](/guide/how-to-find-the-keystone-parcels-in-a-watershed?from=guide) walks through it. ## next The next post in this series gives the method away: [how to find the keystone parcels in a watershed](/guide/how-to-find-the-keystone-parcels-in-a-watershed?from=guide). If you run an intake, a plant, or a corridor and want to know what sits at the top of your shed, [utilities](/solutions/utilities?from=guide&topic=keystone-parcels) shows the source-watershed work. If you can already name the forest and two others who stand on it, [tell us all three](/contact?from=guide&topic=keystone-parcels). ## sources [Cumming, G.S. 2025. Conceptualizing and measuring ecological spillover effects from protected areas. *Frontiers in Ecology and the Environment*.](https://doi.org/10.1002/fee.70008) — Spillover boundaries and decay. [Garibaldi, L.A. et al. 2013. Wild pollinators enhance fruit set of crops regardless of honey bee abundance. *Science*.](https://doi.org/10.1126/science.1230200) — Wild pollinators from nearby habitat raised fruit set across 41 crop systems. [De Frenne, P. et al. 2019. Global buffering of temperatures under forest canopies. *Nature Ecology & Evolution*.](https://doi.org/10.1038/s41559-019-0842-1) — Canopy lowers maximum temperatures by about 4.1°C on average. [Karp, D.S. et al. 2018. Crop pests and predators exhibit inconsistent responses to surrounding landscape composition. *PNAS*.](https://doi.org/10.1073/pnas.1800042115) — 132 studies, 6,759 sites. [NYC Watershed Memorandum of Agreement, 1997](https://nycwatershed.org/wp-content/uploads/2026/03/nyc_watershed_moa_1997.pdf) — The agreement signed 21 January 1997. ## the series 1. [what is a keystone parcel](/guide/what-is-a-keystone-parcel?from=guide) 2. [does protecting one parcel help the land around it](/guide/does-protecting-one-parcel-help-the-land-around-it?from=guide) 3. [what is a serviceshed](/guide/what-is-a-serviceshed?from=guide) 4. [how to find the keystone parcels in a watershed](/guide/how-to-find-the-keystone-parcels-in-a-watershed?from=guide) 5. [the free rider is standing on a keystone parcel](/guide/the-free-rider-is-standing-on-a-keystone-parcel?from=guide) 6. [how a keystone parcel gets paid](/guide/how-a-keystone-parcel-gets-paid?from=guide)