def save_state_gauges(out_fn, bbox=None):
    url = 'http://gis.srh.noaa.gov/arcgis/services/ahps_gauges/' + \
          'MapServer/WFSServer'
    parms = {
        'version': '1.1.0',
        'typeNames': 'ahps_gauges:Observed_River_Stages',
        'srsName': 'urn:ogc:def:crs:EPSG:6.9:4326',
    }
    if bbox:
        parms['bbox'] = bbox
    try:
        request = 'WFS:{0}?{1}'.format(url, urllib.urlencode(parms))
    except:
        request = 'WFS:{0}?{1}'.format(url, urllib.parse.urlencode(parms))
    wfs_ds = ogr.Open(request)
    if wfs_ds is None:
        raise RuntimeError('Could not open WFS.')
    wfs_lyr = wfs_ds.GetLayer(0)

    driver = ogr.GetDriverByName('GeoJSON')
    if os.path.exists(out_fn):
        driver.DeleteDataSource(out_fn)
    json_ds = driver.CreateDataSource(out_fn)
    json_ds.CopyLayer(wfs_lyr, '')
Save stream gauge data to a geojson file.
dataset/ETHPy150Open cgarrard/osgeopy-code/Chapter4/listing4_3.py/save_state_gauges