1. Conservation
1.1. Carry contest
1.2. Rainwater collection
1.3. Purification
1.3.1. Filters
1.3.2. Testing
1.4. Farming
1.4.1. Chemicals
1.4.2. Pesticides
1.5. Rivers
1.5.1. Culture
1.5.2. Civilization
1.5.3. Tourism
1.5.4. Economy
1.5.5. Flooding
1.6. Politics
1.6.1. Water rights
2. Sports
2.1. Boating
2.1.1. Floating
2.1.2. Kayaking
2.1.3. Jetskis
2.2. Swimming
2.2.1. Distance
2.2.2. Speed
2.2.3. Synchronized
2.3. Polo
2.4. Skiing
3. Health
3.1. Dehydration
3.1.1. Kidney function
3.1.2. Sickness
3.2. Fitness
3.3. Education
3.3.1. College
3.3.2. Family
3.3.3. Childhood
3.4. Nursing
3.4.1. Clinics/Hospitals
4. Climate
4.1. Global warming
4.1.1. Melting ice caps
4.1.2. Science
4.1.3. Conspiracies
4.2. Tropical
4.2.1. Beaches
4.2.2. Palm trees
4.2.3. Warmth
4.2.4. Sun
5. Ice
5.1. Plunge
5.1.1. Fundraiser
5.2. Bucket over head
5.2.1. ALS
5.2.2. Athletics celebration
5.2.2.1. Superbowl
5.3. Skating
5.3.1. Speed
5.3.2. Figure
5.3.3. Dancing
6. Mist
6.1. Cooling
6.2. Horticulture
7. Water
7.1. Cold
7.1.1. Drinking
7.2. Warm
8. Snow
8.1. Snowboarding/sledding
8.2. Snowman
8.2.1. Building
8.2.2. Carving/Sculpting
8.2.3. Decorating
8.3. Igloo
8.3.1. Culture
8.3.2. History
8.4. Driving
8.4.1. Accidents
8.5. Salt trucks
8.6. Weather tires
9. Horticulture
9.1. Gardening
9.1.1. Botanical
9.1.2. Residential
9.1.3. Clubs
9.1.4. Tours
9.2. Restoration Ecology
9.2.1. Training and jobs
9.2.2. Conservation