Watershed Pauline Demerjian Mariela Gonzalez Rodolfo Salgado Anthony Blanco Kevin Albanes Diana Perez

What is a Watershed? Area of land that drains all the streams and rainfall to a common outlet such as the outflow of a reservoir (lake, water bank), mouth of a bay, or any point along a stream channel Consists of: surface water--lakes, streams, reservoirs, and wetlands-- and all the underlying ground water Important because the streamflow and the water quality of a river are affected by things, human-induced or not, happening in the land area "above" the river-outflow point Outflow Point- all of the land that drains water to the outflow point is the watershed for that outflow location Larger watersheds contain many smaller watersheds

Characteristics Soil characteristics: Soils absorbing less water results in more runoff overland into streams Soil saturation: Like a wet sponge, soil already saturated from previous rainfall can't absorb much more... thus more rainfall will become surface runoff. Slope of the land: Water falling on steeply-sloped land runs off more quickly than water falling on flat land. Watershed Surface: watershed is the area of reception of the rainfalls and of supplying the watercourse; the outlet flows depending thus on its surface Land cover: Some land covers have a great impact on infiltration and rainfall runoff.. Flooding becomes more prevalent as the area of impervious surfaces increase Infiltration: When rain falls on dry ground, some of the water soaks in, or infiltrates the soil.

Water Cycle Process Precipitation: amount of precipitation that falls in the watershed = greatest factor controlling streamflow most of the precipitation that falls within the drainage area of a stream's monitoring site collects in the stream and eventually flows by the monitoring site Transpiration: The root systems of plants absorb water from the surrounding soil in various amounts. Most of this water moves through the plant and escapes into the atmosphere through the leaves. Vegetation slows runoff and allows water to seep into the ground. Evaporation: Water from rainfall returns to the atmosphere largely through evaporation. The amount of evaporation depends on temperature, solar radiation, wind, atmospheric pressure, and other factors. Infiltration: When rain falls on dry ground, some of the water soaks in, or infiltrates the soil. Some water that infiltrates will remain in the shallow soil layer, where it will gradually move downhill, through the soil, and eventually enters the stream by seepage into the stream bank

27 th Congressional District

Size/Area Los Angeles River Watershed covers approximately 834 square miles Longest River in Watershed Los Angeles River: 48miles- 55miles Land Uses Residential: 37% Open space/Agricultural: 44% Commercial: 8% Industrial: 11%

Prevention/ Improvement Compost your grass clippings: Keep your grass clippings off of hard surfaces(sidewalks, driveways, streets) from which they can be washed away, ultimately ending up in our waters. don’t cut your grass lower than 3 inches in the summer. Slightly longer grass will stay greener, reducing the need for watering Regularly clean leaves from your gutters so they can’t be washed away with the rain Use fertilizer wisely: Nutrients that help lawn grow are the same nutrients that help aquatic vegetation, like algae, to grow Properly dispose of household hazardous waste: gasoline, paint, pesticides, antifreeze, motor oil, etc.. (dispose at county waste site). Effect on our waters can be devastating

"We are killing the lakes and wetlands in our neighborhood. Each of us, with our seemingly harmless everyday yard work, has a small part in it, but together the effects are becoming very significant." -Jim Perry