Geology 59 Puerto Rico Politics and government 50 Puerto Rico 48 Groundwater 47 Reservoir sedimentation 42 Water-supply 32 Self-determination, National 30 Puerto Rico Relations 29 United States Relations 29 Aquifers 28 Statehood (American politics) 22 Geology, Stratigraphic 20 Floods 18 Puerto Rico Economic conditions 18 Sedimentation and deposition 18 Water quality 18 Hurricanes 17 Hydrogeology 16 Disaster relief 15 Hurricane Maria, 2017 15 Sediments (Geology) 15 Hurricane damage 14 Puerto Rico History 14 El Yunque National Forest (P.R.) 13 Debts, Public 12 Puerto Rico Appropriations and expenditures 12 Stream measurements 12 Groundwater flow 10 Hydrology 10 Referendum 10 Rules and practice 10 Budget deficits Law and legislation 9 Debts, Public Law and legislation 9 Emergency management 9 Groundwater Quality 9 Hurricane Irma, 2017 9 Plebiscite 9 Water table 9 Financial crises 8 Forest management 8 Karst 8 Marine sediments 8 Puerto Ricans 8 Reservoirs 8 Wildlife refuges 8 Forests and forestry 7 Groundwater flow Mathematical models 7 Landslides 7 Mines and mineral resources 7 Puerto Rico Social life and customs 7 Water resources development 7 Debt relief 6 Forest policy 6 Land titles Registration and transfer 6 Sand 6 Streamflow 6 United States 6 Water use 6 Appropriations and expenditures 5 Auditing 5 Electric power systems Natural disaster effects 5 Evaluation 5 Groundwater Pollution 5 History 5 Irrigation 5 Lake sediments 5 Timber 5 Watershed management 5 Bankruptcy 4 Carraízo Reservoir (P.R.) 4 Coasts 4 Conflict of interests 4 Coral reefs and islands 4 Disclosure of information Law and legislation 4 Finance, Public 4 Flood control 4 Forest management Law and legislation 4 Forest reserves Recreational use 4 Forest surveys 4 Forests and forestry Citizen participation 4 Formations (Geology) 4 Geochemistry 4 Land use 4 Older people Services for 4 Pilot guides 4 Puerto Rico Foreign relations 4 Rain and rainfall 4 Renewable energy sources 4 Saltwater encroachment 4 San Juan National Historic Site (San Juan, P.R.) 4 Stream-gaging stations 4 United States Foreign relations 4 Water consumption 4 Watersheds 4 Benthos Habitat 3 Borings 3 Budget deficits 3 Channels (Hydraulic engineering) 3 Clemency Political aspects 3 Climatic changes 3