Add RFC data

RFC Products on Arc Servers:

Current Streamflow Conditions (updated hourly):
- https://services6.arcgis.com/ubm4tcTYICKBpist/ArcGIS/rest/services/StationInformation/FeatureServer/0
- http://bcrfc.env.gov.bc.ca/freshet/map_all_wsc.html

Flood Advisories and Warnings (updated as needed):
- https://services6.arcgis.com/ubm4tcTYICKBpist/ArcGIS/rest/services/BC_Flood_Advisory_and_Warning_Notifications_(Public_View)/FeatureServer/0
- http://bcrfc.env.gov.bc.ca/warnings/index.htm

COFFEE Flow Forecast (updated often, more frequently during winter and freshet):
- https://services6.arcgis.com/ubm4tcTYICKBpist/ArcGIS/rest/services/coffee_MapHub_forecast/FeatureServer/0
- http://bcrfc.env.gov.bc.ca/fallfloods/map_coffee.html

CLEVER Flow Forecast (updated often, more frequently during winter and freshet):
- https://services6.arcgis.com/ubm4tcTYICKBpist/ArcGIS/rest/services/CLM_MapHub_forecast/FeatureServer/0
- http://bcrfc.env.gov.bc.ca/freshet/map_clever.html

ELF Lowflow Forecast (updated as needed, usually during summer/fall):
- https://services6.arcgis.com/ubm4tcTYICKBpist/ArcGIS/rest/services/MapHub_ELF_Forecast/FeatureServer/0
- http://bcrfc.env.gov.bc.ca/lowflow/map_elf.html

Drought Levels (updated through drought season; not RFC product but supported):
- https://services6.arcgis.com/ubm4tcTYICKBpist/ArcGIS/rest/services/British_Columbia_Drought_Levels_View/FeatureServer/1
- Drought Portal: https://governmentofbc.maps.arcgis.com/apps/MapSeries/index.html?appid=838d533d8062411c820eef50b08f7ebc

7-Day Flows on Drought Portal (updated daily):
- https://services6.arcgis.com/ubm4tcTYICKBpist/ArcGIS/rest/services/maphub_7dayflow/FeatureServer/0
- http://bcrfc.env.gov.bc.ca/lowflow/map_7dayflow.html
- Also on Drought Portal: https://governmentofbc.maps.arcgis.com/apps/MapSeries/index.html?appid=838d533d8062411c820eef50b08f7ebc

Groundwater Levels on Drought Portal (updated daily):
- https://services6.arcgis.com/ubm4tcTYICKBpist/ArcGIS/rest/services/maphub_groundwaterlevels/FeatureServer/0
- https://governmentofbc.maps.arcgis.com/apps/webappviewer/index.html?id=6460b34e5dcb4084882d92ece77e2685
- Also on Drought Portal: https://governmentofbc.maps.arcgis.com/apps/MapSeries/index.html?appid=838d533d8062411c820eef50b08f7ebc

Snow Basin Indices (updated monthly/bimonthly through winter/spring):
- https://services6.arcgis.com/ubm4tcTYICKBpist/ArcGIS/rest/services/Snow_Basins_Indices_View/FeatureServer/0
- https://governmentofbc.maps.arcgis.com/apps/webappviewer/index.html?id=b57800e08e46468bab506f9b9f0cbad6
- Also on Drought Portal: https://governmentofbc.maps.arcgis.com/apps/MapSeries/index.html?appid=838d533d8062411c820eef50b08f7ebc