# usgs-water-mcp-server [Health: Active]
**Category:** π» Developer Tools
**Repository:** https://github.com/cyanheads/usgs-water-mcp-server
**GitHub Stars:** 1
**Views:** 0
**Installs:** 0
**Upvotes:** 0
**Directory Page:** https://allmcps.com/mcp/usgs-water-mcp-server
## Description
Query real-time and historical USGS water data from ~8,000 stream gages and groundwater wells.
## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `bunx` (confidence: high):
```json
"mcpServers": {
"usgs-water-mcp-server": {
"command": "bunx",
"args": ["@cyanheads/usgs-water-mcp-server@latest"]
}
}
```
## Documentation & README
@cyanheads/usgs-water-mcp-server
Query real-time and historical water data from ~8,000 USGS stream gages and groundwater wells via MCP. STDIO or Streamable HTTP.
7 Tools β’ 2 Resources
[](./CHANGELOG.md) [](./LICENSE) [](https://github.com/users/cyanheads/packages/container/package/usgs-water-mcp-server) [](https://modelcontextprotocol.io/) [](https://www.npmjs.com/package/@cyanheads/usgs-water-mcp-server) [](https://www.typescriptlang.org/) [](https://bun.sh/)
[](https://github.com/cyanheads/usgs-water-mcp-server/releases/latest/download/usgs-water-mcp-server.mcpb) [](https://cursor.com/en/install-mcp?name=usgs-water-mcp-server&config=eyJjb21tYW5kIjoibnB4IiwiYXJncyI6WyIteSIsIkBjeWFuaGVhZHMvdXNncy13YXRlci1tY3Atc2VydmVyIl19) [](https://vscode.dev/redirect?url=vscode:mcp/install?%7B%22name%22%3A%22usgs-water-mcp-server%22%2C%22command%22%3A%22npx%22%2C%22args%22%3A%5B%22-y%22%2C%22%40cyanheads%2Fusgs-water-mcp-server%22%5D%7D)
[](https://www.npmjs.com/package/@cyanheads/mcp-ts-core)
**Public Hosted Server:** [https://usgs-water.caseyjhand.com/mcp](https://usgs-water.caseyjhand.com/mcp)
---
## Tools
Five tools for querying USGS water data, plus two for SQL analytics over the DuckDB-backed canvas dataframes that `water_get_series` and `water_find_sites` materialize:
| Tool | Description |
|:-----|:------------|
| `water_list_parameters` | Static lookup of well-known USGS parameter codes with names, units, and domain. No network call. |
| `water_find_sites` | Find USGS monitoring sites by bounding box, state, county, or HUC watershed. Filter by site type and parameter availability. Large match sets spill to DataCanvas. |
| `water_get_readings` | Get the latest instantaneous values (~15 min real-time) for up to 100 USGS sites. |
| `water_get_series` | Get a time series of daily or instantaneous values for a site over a date range. Large ranges spill to DataCanvas. |
| `water_get_conditions` | Get current hydrologic conditions ranked against the full period-of-record percentile statistics. |
| `water_dataframe_describe` | List tables and columns staged on a DataCanvas by `water_get_series` or `water_find_sites`. |
| `water_dataframe_query` | Run a read-only SQL SELECT against the time-series and site tables staged by `water_get_series` and `water_find_sites`. |
### `water_list_parameters`
Static lookup of well-known USGS parameter codes β no network call, instant response.
- Discover that `00060` = Discharge (ftΒ³/s), `00065` = Gage height (ft), `00010` = Temperature (Β°C), `72019` = Depth to water level (ft), and more
- Filter by thematic domain: `streamflow`, `groundwater`, `temperature`, `meteorological`, `water-quality`, or `all`
- Use this first β parameter codes are required by every other water tool
---
### `water_find_sites`
Discover USGS monitoring sites before calling data tools β all other tools require a site number.
- Geographic scoping: bounding box (`"west,south,east,north"` decimal degrees), 2-letter state code, bare 5-digit FIPS county code (e.g. `51013`), or HUC watershed code β either a 2-digit major HUC (`02`) or an 8-digit minor HUC (`02070008`), the only two lengths NWIS accepts
- Site type filtering: `ST` (stream), `GW` (groundwater well), `LK` (lake/reservoir), `SP` (spring), and more
- Parameter filter: only return sites that have data for a specific parameter code β comma-separate to require several (e.g. `00060,00065`)
- Data type filter: require sites with real-time (`iv`), daily (`dv`), or groundwater (`gw`) data
- Returns site number, name, coordinates, type, state/county/HUC codes, and drainage area (expanded mode only) β altitude is included in both modes when USGS records it
- Bounded result set: capped at 500 sites inline, with a `truncated` flag and `upstreamTotal` (the full upstream count) so an oversized query never overflows the response
- **DataCanvas spillover:** when the result is truncated and `CANVAS_PROVIDER_TYPE=duckdb` is set, the full match set is staged to a DuckDB-backed canvas β the response includes `canvas_id` and `table_name` to retrieve every match past the 500 cap via `water_dataframe_query`. Without DataCanvas, narrow the query with additional filters (county, HUC, bbox, parameter, data type) to bring the result under the cap
---
### `water_get_readings`
Get the latest instantaneous (~15 min) values for one or more USGS monitoring sites.
- Batch up to 100 site numbers in a single call
- Accepts any parameter code discoverable via `water_list_parameters`
- Configurable lookback period via ISO 8601 duration (e.g. `PT2H` = last 2 hours, `P7D` = last 7 days)
- Returns per-site, per-parameter records with timestamp, value, unit, and provisional/approved qualifier
- Bounded by design: each series carries its 10 most recent records, with `totalValues` reporting how many the period actually held and `truncated` flagging the cap. Use `water_get_series` when you need the full series
- Partial batches are explicit: requested sites NWIS returns no data for are named in `missingSites` rather than dropped silently
- Groundwater depth available via `parameterCd=72019` (the legacy `gwlevels` endpoint was decommissioned November 2025 β use the IV service instead)
---
### `water_get_series`
Get a historical time series for a site and parameter over a date range.
- Daily values (DV service, one value per day) or instantaneous values (IV service, ~15 min resolution)
- Returns site name, parameter name, unit code, and time-ordered value records with qualifiers
- **DataCanvas spillover:** large date ranges (>500 records) automatically spill to a DuckDB-backed canvas when `CANVAS_PROVIDER_TYPE=duckdb` is set β response includes `canvas_id` and `table_name` for follow-up SQL via `water_dataframe_query`
- Without DataCanvas, returns the most recent 500 records with a `truncated` flag and `totalRecords` count
- Supports chaining: pass a prior `canvas_id` to append data to an existing canvas
---
### `water_get_conditions`
Get current hydrologic conditions placed in full historical context.
- Fetches the current IV reading and the full daily percentile table in parallel
- Classifies the reading: `record-high` (β₯ p95), `above-normal` (p75βp95), `normal` (p25βp75), `below-normal` (p10βp25), `low` (p05βp10), `record-low` (< p05)
- Pairs each class with a `percentileLabel` spelling out the threshold β `record-high` and `record-low` mark percentile-of-record extremes, not verified all-time records, and the label says so where the class name does not
- Ranks against the observation's own calendar day, so a reading near midnight is not compared against the neighboring day's percentiles
- Discloses the granularity approximation in `comparisonBasis`: the reading is instantaneous while the percentiles are approved daily-mean values, so the class is a "how unusual is this" ranking β not a flood-stage or drought determination, which need authoritative thresholds this tool does not fetch
- Validates `site` and `parameterCd` at the schema edge; a well-formed value NWIS still rejects surfaces as the typed `invalid_request` reason rather than an opaque upstream error
- Gracefully degrades when historical context is missing: returns the current reading with `historicalContext: null` and a `historicalContextStatus` saying why β `no_record` (new/short record), `no_matching_day` (no row for the date), or `unavailable` (stat call failed β transient and retryable, kept distinct from a sparse record)
---
### `water_dataframe_describe` / `water_dataframe_query`
In-conversation SQL analytics over the dataframes that `water_get_series` and `water_find_sites` materialize on a DuckDB-backed canvas β time-series tables from the former, full site match sets from the latter.
**Workflow:**
1. Call `water_get_series` with a large date range, or `water_find_sites` with a query that matches more than 500 sites β when DataCanvas is enabled, the response includes `canvas_id` and `table_name`
2. Call `water_dataframe_describe` with the `canvas_id` to confirm the table schema β series tables carry `date_time`, `value`, `qualifiers`, `site_number`, `parameter_cd`, `unit_code`; site tables carry `site_number`, `site_name`, `site_type`, `latitude`, `longitude`, `huc_cd`, and the expanded fields
3. Call `water_dataframe_query` with the `canvas_id` and a SELECT statement to run aggregates, filter, or join
Read-only by default β only SELECT statements are permitted. Results are capped at 10,000 rows; a query matching more comes back with `truncated: true`. Requires `CANVAS_PROVIDER_TYPE=duckdb` in the server environment.
## Resources and prompts
| Type | Name | Description |
|:-----|:-----|:------------|
| Resource | `usgs-water://site/{siteId}` | Site metadata: name, coordinates, type, HUC, state, county, drainage area, and altitude |
| Resource | `usgs-water://parameters` | Full parameter code catalog (same data as `water_list_parameters`) |
All resource data is also reachable via tools. Use `water_find_sites` for geographic site discovery.
## Features
Built on [`@cyanheads/mcp-ts-core`](https://www.npmjs.com/package/@cyanheads/mcp-ts-core):
- Declarative tool and resource definitions β single file per primitive, framework handles registration and validation
- Unified error handling β handlers throw, framework catches, classifies, and formats
- Pluggable auth: `none`, `jwt`, `oauth`
- Swappable storage backends: `in-memory`, `filesystem`, `Supabase`, `Cloudflare KV/R2/D1`
- Structured logging with optional OpenTelemetry tracing
- STDIO and Streamable HTTP transports
USGS NWISβspecific:
- Wraps NWIS IV (instantaneous), DV (daily), site, and stat endpoints β no API key required, fully public
- Input formats checked at the edge against what NWIS actually accepts β site numbers, parameter codes, ISO 8601 periods, HUC, FIPS county, state, and bbox all carry a validated pattern that is advertised in each tool's JSON Schema, so malformed values fail with a pointed message instead of an opaque upstream 400
- HTML error detection: NWIS returns 400 with an HTML body for bad inputs; the service layer extracts NWIS's own message β which names the field it rejected β and maps it to a typed failure
- Multi-site batching: `water_get_readings` accepts up to 100 site numbers in one call
- Provisional vs. approved data qualifiers surfaced on every reading β not hidden from callers
- DataCanvas spillover: `water_get_series` (long date ranges) and `water_find_sites` (match sets past the 500-site cap) stage the full result as a DuckDB-backed table queryable via `water_dataframe_query`
- Groundwater via the IV service using parameter `72019` β the legacy `gwlevels` endpoint was decommissioned November 2025
Agent-friendly output:
- Percentile classification on every conditions response β callers get a `percentileClass` string (`record-high`, `normal`, `record-low`, etc.) they can act on directly without parsing numeric thresholds, plus a `percentileLabel` stating the threshold in plain language so the `record-*` classes are not mistaken for verified all-time records
- Partial success on conditions: when percentiles are missing, the current reading still returns with `historicalContext: null` and a `historicalContextStatus` that separates an empty stat table (`no_record` / `no_matching_day`) from a failed stat call (`unavailable`, transient), rather than collapsing both into an error
- Partial success on batches: `water_get_readings` returns the series it got and names the rest in `missingSites`, so a silently dropped site never reads as a complete answer
- Truncation signals: `water_get_series` reports `totalRecords` and `truncated`, `water_find_sites` reports `upstreamTotal` and `truncated`, and `water_get_readings` reports per-series `totalValues` plus `truncated`, so callers know when a preview is incomplete. `canvas_id` / `table_name` tell them exactly how to retrieve the rest
- Structured content and rendered text agree: every cap and count a tool applies is reported identically in `structuredContent` and in the markdown, so neither class of client sees a different answer
## Getting started
### Public Hosted Instance
A public instance is available at `https://usgs-water.caseyjhand.com/mcp` β no installation required. Point any MCP client at it via Streamable HTTP:
```json
{
"mcpServers": {
"usgs-water-mcp-server": {
"type": "streamable-http",
"url": "https://usgs-water.caseyjhand.com/mcp"
}
}
}
```
### Self-Hosted / Local
Add the following to your MCP client configuration file.
```json
{
"mcpServers": {
"usgs-water-mcp-server": {
"type": "stdio",
"command": "bunx",
"args": ["@cyanheads/usgs-water-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
```
Or with npx (no Bun required):
```json
{
"mcpServers": {
"usgs-water-mcp-server": {
"type": "stdio",
"command": "npx",
"args": ["-y", "@cyanheads/usgs-water-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
```
Or with Docker:
```json
{
"mcpServers": {
"usgs-water-mcp-server": {
"type": "stdio",
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MCP_TRANSPORT_TYPE=stdio",
"ghcr.io/cyanheads/usgs-water-mcp-server:latest"
]
}
}
}
```
To enable DataCanvas for SQL analytics over large result sets (time series and site match sets), add `CANVAS_PROVIDER_TYPE=duckdb` to the `env` block in any of the configs above.
For Streamable HTTP, set the transport and start the server:
```sh
MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp
```
### Prerequisites
- [Bun v1.4.0](https://bun.sh/) or higher (or Node.js v24+).
- No API key required β USGS NWIS is a free, public API.
### Installation
1. **Clone the repository:**
```sh
git clone https://github.com/cyanheads/usgs-water-mcp-server.git
```
2. **Navigate into the directory:**
```sh
cd usgs-water-mcp-server
```
3. **Install dependencies:**
```sh
bun install
```
4. **Configure environment:**
```sh
cp .env.example .env
# Edit .env to set any optional overrides
```
## Configuration
| Variable | Description | Default |
|:---------|:------------|:--------|
| `CANVAS_PROVIDER_TYPE` | Set to `duckdb` to enable DataCanvas spillover for large results from `water_get_series` and `water_find_sites`. | β |
| `USGS_USER_AGENT` | Custom User-Agent string sent to USGS NWIS. USGS requests a descriptive User-Agent per their terms. | `usgs-water-mcp-server/0.2.3 (contact: https://github.com/cyanheads/usgs-water-mcp-server)` |
| `USGS_REQUEST_TIMEOUT_MS` | HTTP request timeout in milliseconds for NWIS calls. | `30000` |
| `MCP_TRANSPORT_TYPE` | Transport: `stdio` or `http`. | `stdio` |
| `MCP_HTTP_PORT` | Port for HTTP server. | `3010` |
| `MCP_SESSION_MODE` | HTTP session mode. This project's `.env.example` and Docker runtime use `stateless`; `auto` resolves to `stateful`. | `stateless` |
| `MCP_AUTH_MODE` | Auth mode: `none`, `jwt`, or `oauth`. | `none` |
| `MCP_LOG_LEVEL` | Log level (RFC 5424). | `info` |
| `LOGS_DIR` | Directory for log files (Node.js only). | `/logs` |
| `OTEL_ENABLED` | Enable [OpenTelemetry instrumentation](https://github.com/cyanheads/mcp-ts-core/tree/main/docs/telemetry) (spans, metrics, completion logs). | `false` |
See [`.env.example`](https://github.com/cyanheads/usgs-water-mcp-server/blob/HEAD/.env.example) for the full list of optional overrides.
## Running the server
### Local development
- **Build and run:**
```sh
# One-time build
bun run rebuild
# Run the built server
bun run start:stdio
# or
bun run start:http
```
- **Run checks and tests:**
```sh
bun run devcheck # Lint, format, typecheck, security
bun run test # Vitest test suite
bun run lint:mcp # Validate MCP definitions against spec
```
### Docker
```sh
docker build -t usgs-water-mcp-server .
docker run --rm -p 3010:3010 usgs-water-mcp-server
```
The Dockerfile defaults to HTTP transport, stateless session mode, and logs to `/var/log/usgs-water-mcp-server`. OpenTelemetry peer dependencies are installed by default β build with `--build-arg OTEL_ENABLED=false` to omit them.
## Project structure
| Directory | Purpose |
|:----------|:--------|
| `src/index.ts` | `createApp()` entry point β registers tools/resources and inits services. |
| `src/config` | Server-specific environment variable parsing and validation with Zod. |
| `src/mcp-server/tools` | Tool definitions (`*.tool.ts`). |
| `src/mcp-server/resources` | Resource definitions (`*.resource.ts`). |
| `src/services/nwis` | NWIS HTTP client β IV, DV, site, and stat endpoints with HTML error detection. |
| `src/services/canvas` | DataCanvas accessor for DuckDB-backed spillover. |
| `tests/` | Unit and integration tests mirroring `src/`. |
## Development guide
See [`CLAUDE.md`](https://github.com/cyanheads/usgs-water-mcp-server/blob/HEAD/CLAUDE.md) for development guidelines and architectural rules. The short version:
- Handlers throw, framework catches β no `try/catch` in tool logic
- Use `ctx.log` for request-scoped logging, `ctx.state` for tenant-scoped storage
- Register new tools and resources via the barrels in `src/mcp-server/*/definitions/index.ts`
- Wrap external API calls: validate raw β normalize to domain type β return output schema; never fabricate missing fields
## Contributing
Issues and pull requests are welcome. Run checks and tests before submitting:
```sh
bun run devcheck
bun run test
```
## License
Apache-2.0 β see [LICENSE](https://github.com/cyanheads/usgs-water-mcp-server/blob/HEAD/LICENSE) for details.