# Monitor Potomac River streamflow in real time (USGS)

**Use case:** 

Stream live discharge readings for the Potomac at Little Falls gauge from USGS NWIS — timestamps, values and threshold alert flags.

## Input

```json
{
  "sites": [
    "01646500"
  ],
  "stateCd": "",
  "parameterCd": "00060",
  "service": "iv",
  "period": "",
  "thresholdValue": "",
  "siteThresholds": {},
  "onlyAlerts": false
}
```

## Output

```json
{
  "site_no": {
    "label": "Site number",
    "format": "string"
  },
  "site_name": {
    "label": "Site name",
    "format": "string"
  },
  "state": {
    "label": "State",
    "format": "string"
  },
  "parameter_code": {
    "label": "Parameter code",
    "format": "string"
  },
  "value": {
    "label": "Value",
    "format": "number"
  },
  "unit": {
    "label": "Unit",
    "format": "string"
  },
  "datetime": {
    "label": "Datetime",
    "format": "string"
  },
  "change": {
    "label": "Change",
    "format": "number"
  },
  "change_direction": {
    "label": "Change direction",
    "format": "string"
  },
  "above_threshold": {
    "label": "Above threshold",
    "format": "boolean"
  },
  "provisional": {
    "label": "Provisional",
    "format": "boolean"
  }
}
```

## About this Actor

This example demonstrates how to use [USGS NWIS Streamflow & Gage Height Monitor API by Site/State](https://apify.com/malonestar/usgs-nwis-streamflow-monitor) with a specific input configuration. Visit the [Actor detail page](https://apify.com/malonestar/usgs-nwis-streamflow-monitor) to learn more, explore other use cases, and run it yourself.