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Hydrology is the distribution and movement of water.

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Presentation on theme: "Hydrology is the distribution and movement of water."— Presentation transcript:

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2 Hydrology is the distribution and movement of water.

3 Stream Morphology is the form and structure of a stream (cross-section, sinuosity, profile).

4 “A river is the report card for its watershed.” Alan Levere, CT DEP Morphologic Stability means no net change in channel shape, which occurs only if channel-forming flows are stable.

5 Extreme flood flows generally have little effect on channel morphology because they are so rare. More frequent flows, those that recur about every 1 to 2 years, are generally the dominant channel-forming flows in stable, natural streams (Schueler, 1987 and Rosgen, 1996). Morphologic Stability means no net change in channel shape, which occurs only if channel-forming flows are stable.

6 Hydrologic changes can cause a stream to be morphologically unstable for 60 years or more.

7 Physical indicator of unstable stream morphology: down-cut

8 A more typical down-cut.

9 Physical indicator of unstable stream morphology: extensive, excessive erosion, especially along straight reaches

10 Sometimes the problem is local and the cause obvious.

11 Sometimes the problem is natural.

12 Characterize the watershed Understand stream flow impacts of hydrologic changes Provide a basis for stormwater management recommendations Help determine critical areas Goals of Hydrologic Analysis for NPS Watershed Management Plans

13 Watershed Elevations

14 Little Portage Lake Toma Road Hi-Land Lake Tiplady Road Halfmoon toWoodburn Lakes Unadilla Road Kane Road M-52 Williamsville toEllsworth Lakes McConachie Lake

15 Stream order provides an indication of stream size and potential power. 1 st to 3 rd order streams may be more sensitive to hydrologic changes. Stream Order Data courtesy of MDNR Institute for Fisheries Research and the USGS Great Lakes Gap

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18 Conservation and Recreation Lands 25% of watershed

19 Percent Imperviousness Excerpted from “The Practice of Watershed Protection” by Thomas Schueler and Heather Holland, p. 15 Urban Stream ClassificationSensitive*ImpactedNon-supporting Channel StabilityStableUnstableHighly unstable Water QualityGoodFairFair-Poor Stream BiodiversityGood-ExcellentFair-GoodPoor Resource Objective Protect biodiversity and channel stability Maintain critical elements of stream quality Minimize downstream pollutant loads * The expected quality of streams in this range of impervious cover is generally influenced more by other watershed characteristics such as forest cover, road density, riparian continuity, and cropping practices. Every Portage Creek subbasin is less than 5% impervious.

20 Land Cover

21 Soils

22 Characterize the watershed Understand stream flow impacts of hydrologic changes Provide a basis for stormwater management recommendations Help determine critical areas Goals of Hydrologic Analysis for NPS Watershed Management Plans

23 Subbasins Non-contributing

24 Runoff from each subbasin for a standard storm is calculated to highlight subbasins that generate a higher proportion of runoff due to soils and land cover Land Cover 2000 Land Cover Runoff Volume per Area 1978 Land Cover

25 Change: 1800 to 2005 Runoff Volume Change per Area

26 Yields are calculated as a measure of hydrologic responsiveness. Flood Flow Yields 1800 Land Cover 1978 Land Cover 2000 Land Cover cfs/acre

27 Yields: Peak Flow per Area 1800 to to 2000

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29 Example of land use change and its effect

30 50 percent chance (2-year) flow Pre-developmentPost-development 70% increase in peak flow, 170% increase in runoff volume, former instantaneous peak flow now lasts ~4 hours

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32 A stream described as flashy responds to rainfall by rising and falling quickly. A stream that is not flashy would rise and fall less for an equivalent rainfall and would typically derive more of its overall flow from groundwater. Flashiness Analysis

33 David Baker, Peter Richards, Timothy Loftus, and Jack Kramer (2004) proposed quantifying flashiness by measuring the path length of flow oscillations for data from gaged streams. Longer paths correlate with flashier streams, while more constant flows have shorter path lengths. Watershed areas and total yearly flow volumes are similar

34 Portage Creek at Tiplady near Pinckney

35 Total Drainage Area: 82 square milesFirst Water Year: 1945 Average R-B Index Value: 0.059Last Water Year: 1971 Rank: lowestNumber of Years Analyzed: 27 Trend: Not Applicable

36 Note: Flows are adjusted to an equivalent drainage area of 79 square miles. Portage Creek at Tiplady River Raisin near Manchester Mill Creek near Dexter Mill Creek near Lima Center Saline River near Saline

37 Portage Creek at Tiplady River Raisin near Manchester Mill Creek near Dexter Mill Creek near Lima Center Saline River near Saline Portage gage compared to 38 statewide gages with similar sized watersheds (80 to 100 sq. mi.). The Portage gage is third lowest, sorted by 2-year peak flow or by 2-year peak flow divided by drainage area. Station IDDA SQ MIQP 2.0Peak/DA Station IDDA SQ MIQP 2.0Peak/DA

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39 Characterize the watershed Understand stream flow impacts of hydrologic changes Provide a basis for stormwater management recommendations Help determine critical areas Goals of Hydrologic Analysis for NPS Watershed Management Plans

40 Water quality, preventing stream channel erosion, and flood control are concerns of watershed planners and stakeholders. The rain events that produce these concerns overlap. In general, small storms, and runoff from the early part of larger storms, are the focus of water quality BMPs. Channel protection measures focus on larger, but still fairly common storm flows. Flood control is generally associated with infrequent events. adapted from Sullivan, 2002

41 Water Quality (First Flush) Channel Shape (Morphology) Flooding Interception, Evapotranspiration, Infiltration Precipitation

42 Small storms and the first part of the runoff from larger storms typically carry most of the pollutants to an urban stream. First Flush Treatment

43 From Gun River Hydrologic and Hydraulic Study, Appendix 6 Extended Detention

44 Low Impact Development (LID)  LID integrates stormwater practices throughout the site, preserves natural functions, and reduces impervious surfaces Bioretention/rain garden Grassed swale Green roofs Porous pavement Stormwater reuse Preservation of natural features Native plantings East Hills Center Green Roof Bazzani Associates Porous Pavement Pokagon Edewat subdivision

45 Characterize the watershed Understand stream flow impacts of hydrologic changes Provide a basis for stormwater management recommendations Help determine critical areas Goals of Hydrologic Analysis for NPS Watershed Management Plans

46 IDSubbasin Runoff Volume, 2000 Runoff Volume Change, 1800 to 1978 Runoff Volume Change, 1978 to 2000 Peak Flow Yield, 2000 Peak Flow Yield Change, 1800 to 1978 Peak Flow Yield Change, 1978 to 2000 Imperviousness, 2000 Total Score 1 Portage Creek to mouth/Little Portage Lake outlet Unnamed tributary to mouth/Little Portage Lake Portage Creek to Tiplady Road, Gage # Portage Creek to Hi-Land Lake outlet in Hell Unnamed tributary to Hi-land Lake Portage Creek to Woodburn Lake Livermore Creek to Woodburn Lake Portage Creek to confluence with unnamed trib, in Unadilla Unnamed tributary to mouth in Unadilla Portage Creek to Williamsville Lake outlet Stockbridge Drain to mouth at Williamsville Lake Portage Creek to Ellsworth Lake Unnamed tributary to Ellsworth Lake Portage Creek to McConachie Lake outlet Unnamed tributary to McConachie Lake Portage Creek to unnamed tributary near Stockbridge Unnamed tributary to mouth near Stockbridge

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48 Thank you


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