We all live in a watershed. Watersheds are natural boundaries where water cycles into a common source, be it a river, wetland, or ocean. The hydrologic cycle is the engine that moves water around the watershed. First, water falls to the earth as precipitation. Imagine the earth as a sponge, with the soil soaking this precipitation up to be stored for plant uptake. What is not absorbed and stored in the soil runs off as overland flow downhill to a water source. From here, the sun changes the water into vapor through evaporation that goes into the atmosphere. Plants also contribute water to the atmosphere through a process called transpiration. In this process, excess water is evaporated to cool the plant. Together, evaporation and transpiration, or evapotranspiration, contribute water into the atmosphere that then falls down again as precipitation to complete the cycle. Human activity has an enormous impact on watershed quality. As areas develop, hard surfaces called impervious cover such as rooftops, parking lots, and streets replace the soil and increase the amount of water that cannot be stored. This water runs off, and is aptly named runoff. Runoff can pick up pollutants and bring them into a water source, decreasing the water quality for all those plants, animals, and humans living in and depending upon the watershed. Pollution may be further categorized into point and non-point source pollution. Point source pollution comes directly from a source that you can point to, such as a factory or dump site. Non-point source pollution is a cumulative effect of people going about their daily lives, whether it be fertilizing the lawn or driving an automobile. Imagine if all the cars you saw on the road dropped just a little oil on the asphalt. That little bit of oil then compounds into lots of oil to be captured by runoff and deposited into a water source! Thankfully, there are measures to reduce pollution and improve watershed quality. Installing “green roofs” replaces the hard cover of rooftops with vegetation that can reduce runoff by storing amounts of water during a rainfall event. Pervious pavement, which replaces conventional pavement, allows water to enter into pores in the pavement where it can infiltrate the ground and be filtered and stored. Rain gardens and vegetative filter strips are other landscape features that also retain runoff to reduce the intensity of a storm event. These practices, called “Best Management Practices” (BMP’s) ensure that humans can minimize impacts on the environment and create a sustainable future for all! Watershed Word Search BMP EVAPORATION EVAPOTRANSPIRATION GREENROOFS HYDROLOGICCYCLE IMPERVIOUSCOVER NONPOINT PERVIOUSPAVEMENT POINT POLLUTANTS PRECIPITATION RUNOFF TRANSPIRATION WATERSHED S F O O R N E E R G E S U C P T L H P R P R E C I P I T A T I O N F R Z T E H D V Z Y D O N N N Q G M O O R K R R L Y A P T O P R S B O L Z E J W W M V F H D D T I Y V M B S N R P W C P C I R H J R K N O I T A R I P S N A R T O P A V E O E F G L M H P C O R Z L T U T N A I K L Q S T N B P T F I Q W W S N N O Z R V O P U T L Q D E R N A F P W O K I G W J G L R F N L V A R T Y A Q I P T T R K V I Q F U K A O F E V V R T K H J A I G C C L T T N V T R X E I A Y G E I R M K N C U C R V O S U M G R O B R K A O W H Y Y G Y W J H F E L I B C U F H K P L N J C O Q F E V N F P L I E Z S H G A K F W L F E D F T T S J F O A V Y C G V J C K E B C G P C N D Y U M P Y V D O E F W G P Y P Y B A B V C T D G N N B S V U Z M S F F A R X R G C G I K P O I N T E B X J X A T L X O M T G Z E D E X E V K R F S C Where do most people get their drinking water? If you don’t know, find out! What can you do at your school, house or neighborhood that would reduce water pollution? Mercer Museum: What’s Water Got To Do With It? 1. Start your scavenger hunt at Point A on the map. Look for the weathervane on top of the museum. It is called The Rainmaker. If you look closely you can see that the figure is throwing down an object that looks like a sword. What does the sword symbolize or represent? Look around you. What possible water pollutants might begin here in this parking lot and on the grounds of this building? Why do you think the surface of the porous pavement has pores? (Look closely the surface looks like black rice crispy treats) 2. Walk over to the garden at Point B on the map. Do you recognize any of the plants in this garden? What is different about this garden than those you have seen in this or your neighborhood in the past? How do you think this garden reduces water pollution? Besides reducing water pollution, what else might this garden provide that was not provided by the lawn which was here before the rain garden was planted? 3. Walk up the slope and stand on Ashland Street above Point C on the map.. What is on the roof? What happens to rain that falls on a regular roof? What do you think happens to the rain that falls on the green roof that is different than what happens on a conventional roof? If it rains very hard, what do you think might happen that would involve the rain garden? 4. If time allows, walk to Points D and E on the map. Look at the tile on the corner walls. Which of these tiles depict or show things that might depend upon clean water?