Setting the Course for Improved Water Quality Streamflow, Stream Shape and Connectivity in Watersheds Minnesota Pollution Control Agency A TMDL traininggp prog ram f or local g overnment leaders and other water resource managers – Session 5b wq-iw3-55b TMDL studies take a watershed approach y cc Watershed – an area of land that drains to a l Agen common point (lake, oo stream, wetland, estuary) Watersheds are the basis Contr for water quality planning and management since ollution PP they in tegra te philhysical, chemical and sota ee biological processes Minn This module focuses on the physical processes within a wathdhihtershed which affect water quality… specifically, hyygydrology and geomorphology In this presentation y cc The distribution, circulation, and Hydrology behavior of water within a watershed l Agen oo The geologic forces that shape the Geomorphology landscape, largely through the action Contr and effects of moving water ollution Linkinggpy the physical watershed, PP Connectivity water chemistry and biological systems together as a whole sota ee Importance of these concepts to watershed management Minn Part 1: Hydrology y cc The distribution, circulation, and Hydrology behavior of water within a watershed l Agen oo The geologic forces that shape our Geomorphology landscape through the action and Contr effects of moving water ollution Linkinggpy the physical watershed and PP Connectivity chemical factors to biological systems sota ee Minn The hydrologic cycle y One of the most impp,ortant, cc basic concepts in hydrology, which includes: l Agen oo EtiEvaporation Condensation Contr Precipitation Infiltration ollution Surface runoff PP Storage (groundwater, lakes, wetlands, streamflow) sota ee Minn Streamflow – an important part of the hydrologic cycle y cc Water that comes together in a channel l Agen oo from precipitation Contr storage groundwater ollution PP wetlan ds sota lakes ee Minn Streamflow has great significance in any TMDL study Streamflow – hhjas two major components y cc Base flow Stormflow precipitation that precipitation that l Agen o o percolates to reaches the channel groundwater before after a short period Contr reaching the stream through overland channel runoff or ollution PP underground flow sota ee Minn To understand streamflow – we must hddhave good data y cc Streamflow data is needed from a range l Agen oo of hydrologic conditions (base, average, high flow) Contr to characterize water quality ollution PP sota ee Minn Tools to improve understanding of streamflow in watersheds y cc HdHydrograp h a graphic plot showing: l Agen amount and speed of o o changes in streamflow over time flow Contr and relationship between ollution PP streamflow and the Changes in pollutant mass load of pollutants sota concentrations over ee carried by the stream time Minn Example of a hydrograph – graphic plot showing changes in streamflow and suspended solids concentrations over time y cc 1400 1660 1200 l Agen s oo 1000 6575 800 Contr rge (cf 232 Flow 600 smpl collected 1380 400 327 Discha 354 ollution 140 PP 200 1730 606 673 53 12-61 0 sota ee 3/30 4/19 5/9 5/29 6/18 7/8 7/28 8/17 9/6 9/26 Date Minn Data courtesy of High Island Creek Watershed Project Stream order y cc Stream order BiBasins an d One way to watersheds l Agen contain streams o o categorize, describe of different sizes streams according to and locations Contr size Streams join ollution to form a PP branching sota network ee Minn Stream order – numbered from 1-10 y cc First order fledgling streams l Agen (springs, seeps, bogs, o o lakes) Second order Contr result of two first order streams meeting ollution P P sota c/o MDNR ee Minn Stream order Fourth/fifth order streams – for swimming, anglers and y cc First order streams – canoeitists sometimes only a trickle l Agen oo Contr ollution PP Tenth order – sota ee lower Mississippi River (used for transportation) Minn Photo: B.L. Johnson, USGS Drainage density y cc Drainage density l Agen oo affects how quickly the watershed Contr moves precipitation from high to ollution low elevations PP sota ee c/o MDNR Minn What factors affect streamflow? y cc Climate usually the predominant influence l Agen Weather conditions and amount of o o precipitation Seasonal patterns – precipitation, Contr prior conditions, intensity of precipitation and temperature ollution Toppgograp pyhy – the slope of the land P P and the stream channel have a major influence sota ee Minn Climate and weather affect streamflow y c c Snowmelt and spring storms often produce the highest annual peak l Agen o o streamflow Contr ollution P P sota ee Minn Minnesota Pollution Control Agency Streamflow Streamflow usually declines in summer affects streamflow Weather usually declines in summer Weather affects streamflow y cc In winter, streams are fed by groundwater, l Agen o o lakes and wetlands (base flow) Contr ollution P P sota ee Minn Seasons affect streamflow y cc Streamflow patterns change Stream at across seasons and landscapes l Agen oo Each stream has a typical flow pattern throughout the Contr year low flow Streams with significantly ollution different watershed PP characteristics will exhibit different hydrographs sota ee high flow Minn c/o MnDNR Minnesota Pollution Control Agency Hydrograph a Seasons ff ect stream fl ow c/o MnDNR Natural variations over time affect streamflow y cc Streamflow changes across years l Agen oo Contr ollution PP sota ee c/o MnDNR Minn Topography affects streamflow y cc Topography of a watershed affects how much water flows into a stream – steep hills drain quickly l Agen oo Contr ollution PP sota ee Minn Topography affects streamflow y cc Flat terrain drains slowly l Agen o o Contr ollution P P sota ee Minn What other factors affect streamflow? y cc 1. Subsurface flow – water stored in soils above the l Agen stream channel o o 2. Loss of vegetative cover – Contr decreases infiltration, increases runoff ollution 3. Human activities on the P P land sota ee Minn 1. Subsurface flow affects streamflow Water stored in uplands is y disppylaced by cc new Water stored in soils precipitation l Agen above the stream o o channel contributes Contr to flow downstream due to displacement ollution P P sota ee Minn Water displacement and streamflow y cc When turning on a garden hose warmed by the sun, cold water eventually l Agen displaces warm water in the hose. oo Similarly, new water eventually Contr displaces old water in a watershed. ollution PP Uplands sota ee River/Stream Minn 2. Loss of vegetative cover affects streamflow y cc Removal of plant cover affects amount, timing and quality of flow into streams l Agen oo Int ercepti on, i nfilt ra tion, pl an t uptake is decreased Contr Runoff over barren soils is typically quicker Lack of organic matter (crops, ollution vegetation) and more paved PP surfaces increase runoff significantly sota ee Pollutant load to waterbodies often increases Minn Minnesota Pollution Control Agency a Vegetative cover ff ects stream fl ow 3. Land use/human activity affects streamflow y cc Examples: Wetland drainage l Agen Agricultural oo drainage Home Contr consttitruction Road building ollution Agriculture PP Clear-cutting sota forests ee What do these pictures have Minn in common? Common impacts of human actiiiivities i n a waters hdhed y cc 1. Changes in vegetative cover l Agen oo 2. Reduction in soil-infiltration capabilities Contr 3. Alteration of stream channel or land slope Loss of retention/detention storage in 4. ollution watershed PP 5. Increased streamflow sota ee Minn Part II: Geomorphology y cc The distribution, circulation, and Hydrology behavior of water within a watershed l Agen oo The geologic forces that shape Geomorphology our landscape through the action Contr andfftd effects o f mov ing wa ter Linking the physical watershed and ollution PP Connectivity chemical factors to biological systems sota ee Minn Geomorphology y cc The action and effects of moving l Agen oo water affect the shape of the stream Contr channel ollution PP sota ee ©Explore MN Tourism Minn Large-scale geologic forces shhldhape the land y cc Geologic forces form a landscape: l Agen volcanoes, oo earthquakes, glaciers, Contr deposition Water flowing over different ollution PP landscapes responds differently sota hoto: USGS PP ee Photos: c/o USGS Minn Soils affect streamflow y Soil type influences how quickly water cc will move through the ground l Agen oo Outwash sand High infiltration vs. Contr Lacustrine clay Low infiltration ollution PP Carbonate bedrock High infiltration sota vs. ee Igneous bedrock Low infiltration Minn Soils affect stream fl ow y cc TherateatwhichThe rate at which precipitation can infiltrate l Agen the soil depends upon: oo 1.Texture Contr 2.Structure 3.Surface conditions ollution 4.Preseeseceonce of l agepoesarge pores PP 5.Prior soil moisture levels. sota ee etc. Minn Small-scale geologic forces shhlhape stream channels y cc Interplay between the force of moving water l Agen and the physical oo characteristics of the stream channel: Contr erosion ollution deposition PP resuspension sota ee channel stability Photo by Joe Magner Minn Stream channel shape and fifunction y cc l Agen oo Contr ollution PP c/o US EPA Watershed Academy sota ee Nearly all channels are formed, maintained, and altered by the water and sediment they carry Minn Bank-full flows ddfiefine a r iver ’s s hape y cc Bank-full refers to the water level stage that just begins to spill out of l Agen the channel into the floodplain, occurring about every 2.3 o o years (averaged over wet and dry years) Contr ollution PP sota ee c/o MnDNR Minn What affects a stream channel’s sh?hape? y cc Changes in streamflow regimes, channel modifications l Agen oo and floodplain alterations Contr ollution PP Change c hanne l s hape sota ee Minn Stream channel shape ddd10iblepends on 10 variables (Adapted from Leopold et.