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What is a Watershed?

What is a Watershed?. An area of land, from ridge top to ridge top, that collects, stores, and releases water to a common point, such as a river or a lake. Streams Rivers Lakes Wetlands Hills Mountains. Farms Cities Houses Humans Animals Plants. What’s in a Watershed?.

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What is a Watershed?

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  1. What is a Watershed? • An area of land, from ridge top to ridge top, that collects, stores, and releases water to a common point, such as a river or a lake

  2. Streams Rivers Lakes Wetlands Hills Mountains Farms Cities Houses Humans Animals Plants What’s in a Watershed?

  3. Watershed Components

  4. Watershed Processes • Precipitation • Evaporation • Infiltration • Runoff • Erosion

  5. Impacts on Watershed • Land Use • Pollution • Too much of a good thing • Point Sources • Non-Point Sources • Erosion • Natural • Human-accelerated

  6. Watershed Study PHYSICAL Width Water Color Depth Streambank Bottom Materials Shading (canopy) Soils/Rocks Flow Temperature Dams Turbidity Flow Alterations BIOLOGICAL Bacteria Animals Viruses Fish Plankton Plants Macroinvertebrates Algae CHEMICAL pH Alkalinity Dissolved Oxygen BOD Conductivity Toxics Phosphorus Nitrates Chlorine/Chloride Heavy Metals

  7. “Water Quality” • Water shed to stream = easier to measure • Water Quality is primarily chemistry • “Quality” is a value judgement based on intended use • Drinking water • Recreation • Aquatic life

  8. Water Quality Parameters • Temperature • Dissolved Oxygen • BOD • pH • Alkalinity • Turbidity/Total Suspended Solids • Phosphorus • Nitrate • Chlorine/Chloride

  9. Temperature • Most aquatic organisms are poikilothermic - don’t internally regulate their body temp • The rate of many chemical reactions increases at higher temperatures. • Oxygen solubility  as temperature  • Loss of riparian shading • Water inputs (Industrial, Groundwater, etc) • Weather •  Turbidity can temperature

  10. Temperature • Measure of heat • Temperature scales • Equipment • Data Loggers • Thermometers 0°C 100°C 32°F 212°F

  11. Dissolved Oxygen • Photosynthesis ( DO) • Atmospheric Re-aeration ( DO) • Inflow of oxygenated water ( DO) • Respiration ( DO) • Biochemical Oxygen Demand ( DO) • Nitrification (NBOD) NH3 + O2 = NO3

  12. Dissolved Oxygen • Measure of O2 in water • BOD is difference in DO after 5 days • Measures oxygen-consuming waste present in water • Equipment • DO meter • Winkler titration

  13. pH • Organisms have optimal range (6.5 – 8.5) • pH controls availability and “speciation” of many chemicals • Photosynthesis ( pH) • Respiration ( pH) • “Acid” Rain (pH < 5.6) caused by NOx and SO2 • Industrial Wastewater

  14. pH • Measure of hydrogen ion concentration • Equipment • Color indicators • pH Meter

  15. Alkalinity • Calcium carbonate CaCO3 – lime • Carbonic acid – CO2 + H2O = H2CO3 • Bases (OH-) • Phosphate (PO43-) • Wastewater • Stormwater Runoff

  16. Alkalinity • Measure of acid buffering capacity • Equipment • Acid (H2SO4) titration • pH endpoint (~pH 4.5) can be measured using color indicator or pH meter • Bromcresol Green- Methyl Red – changes from green to pink at pH 4.5 7.0 pH 4.5 Drops acid added

  17. Turbidity/Total Suspended Solids • Caused by sediment, algae and organic material • Inhibits plant growth • Decreases visibility for visual feeders • Inhibits gill respiration • Smothers eggs

  18. 90 Light Detector Transmitted Light Detector Lens Sample Vial Light source Tungsten Lamp Turbidity • Measure of light scattering • Equipment • Secchi disk • Turbidity tube • Turbidimeter

  19. Water sample Total suspended solids (TSS) Glass Fiber Filter (0.45 or 1.0 μm) Total dissolved solids (TDS) Total Suspended Solids • Measure of solids in water • Equipment • Filter funnel • 1.0 m filter • Drying oven • Dessicator

  20. Nutrients • Phosphorus and Nitrogen - essential “macronutrients” for plants and animals • Usually not obtained from air • “Limiting nutrients” • Excess can lead to Eutrophication

  21. Phosphorus • Soluble Reactive Phosphorus (SRP) • aka orthophosphorus (PO43-), but due to pH, most will be HPO42- or H2PO4- • “bio-available” P • Total Phosphorus • SRP + bound phosphorus • P adsorbs to surfaces of organic & inorganics (suspended sediment) • P absorbs into large organic & inorganics

  22. Nitrogen • Ammonia (NH3) and nitrate (NO3) are 2 most common forms • Ammonia can be NH3 (toxic) or NH4+ (ammonium) • Nitrate is VERY soluble & preferred N source for plants. • Nitrate toxic >10 mg/L

  23. Chlorine and Chloride • Chlorine (Cl2) • Doesn’t occur naturally • Used for water treatment • Good indicator of human impacts • Chloride (Cl-) • Naturally present in salts • Can be an indicator of human impacts

  24. Light Detector - Absorbance Lens Sample Vial Filter Light source Tungsten Lamp Nutrient Measurement • Colorimetry - Color Change • Colorimeter quantifies color change

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