# x402-seller Flood Risk at US River Gauge

> x402-seller Flood Risk at US River Gauge is a paid API for AI agents from x402-seller.onrender.com, paid per call via x402, $0.31/call, status unknown (last checked 2026-09-14).

Returns current flood risk at a US river gauge by comparing the live water level to official NWS flood stages (action, minor, moderate, major) and providing NOAA observed and forecast flood categories.

## Facts

- Endpoint: GET https://x402-seller.onrender.com/water/flood-risk
- Price: $0.31/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-seller-flood-risk-at-us-river-gauge-f9e05818
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ztWA7l0MczTGW4v2bIthS

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402-seller-flood-risk-at-us-river-gauge-f9e05818
```

Example prompt: Is the Potomac River at USGS gauge 01646500 close to flooding? Tell me what flood stage it's at and how many feet remain before each NWS threshold — action, minor, moderate, and major.

## When to prefer this

Use this endpoint when you need official NWS flood stage context — not just raw streamflow numbers — for a specific US river gauge. It is ideal when you want to know how close a river is to action, minor, moderate, or major flood stage rather than just the raw cubic feet per second or gage height. Prefer this over the raw USGS stream conditions endpoint when flood risk assessment and NOAA forecast flood categories are required.

## Known failure modes

- Gauge not found: invalid USGS site number or NWS lid returns an error or empty result
- No flood stages defined: gauge exists but NWS has no official flood stages for it
- Stale data: river conditions may lag real-time by minutes to hours depending on reporting frequency
- Missing either 'site' or 'lid' parameter: request requires at least one gauge identifier
- Payment failure: x402 payment of $0.31 USDC not completed

## How this service works

Flood risk at a US river gauge: current water level measured against the official National Weather Service flood stages (action, minor, moderate, major), how many feet remain before each one is reached, and NOAA's own observed and forecast flood category. Answers "is this river near flooding". Takes a USGS site number or an NWS gauge ID. Not every gauge has official flood stages.

## Output

Returns a JSON object with the USGS site info, current gauge reading, official NWS flood stage thresholds (action, minor, moderate, major) in feet, how many feet below each stage the river currently is, the next flood threshold to be reached, NOAA's observed and forecast flood categories, and the water level trend. Not every gauge has official flood stages defined.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "lid": {
       "type": "string",
       "description": "NWS gauge ID (e.g. BRKM2), as an alternative to site"
      },
      "site": {
       "type": "string",
       "description": "USGS site number (e.g. 01646500)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "site": {
       "type": [
        "string",
        "null"
       ]
      },
      "usgs": {
       "type": [
        "object",
        "null"
       ]
      },
      "gauge": {
       "type": "object"
      },
      "trend": {
       "type": [
        "string",
        "null"
       ]
      },
      "source": {
       "type": "string"
      },
      "forecast": {
       "type": "object"
      },
      "observed": {
       "type": "object"
      },
      "floodStagesFt": {
       "type": "object"
      },
      "nextThreshold": {
       "type": [
        "object",
        "null"
       ]
      },
      "feetBelowStage": {
       "type": "object"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-seller-flood-risk-at-us-river-gauge-f9e05818/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-seller.onrender.com](https://www.zero.xyz/host/x402-seller.onrender.com/llms.txt)