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MS4 Flow and Precipitation Monitoring Project

Progress Report

February 6, 2018Dave Braun (Stone) and Joe Bartlett (FEA)

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Stormwater-impaired streams in Chittenden and Franklin Counties

Stream MunicipalityAllen Brook Williston

Bartlett Brook South Burlington, Shelburne

Centennial Brook South Burlington, Burlington

Englesby Brook Burlington, South Burlington

Indian Brook Essex

Morehouse Brook Winooski, Colchester

Munroe Brook Shelburne, South Burlington

Potash Brook South Burlington, Burlington

Rugg Brook St. Albans Town, St. Albans City

Stevens Brook St. Albans City, St. Albans Town

Sunderland Brook Colchester, Essex Junction

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Streamflow and precipitation monitoring stations

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Flow duration curve for Stevens Brook,St. Albans, VT

TMDL to Address Biological Impairment in Stevens Brook, Franklin County, Vermont. October 2008. VTDEC

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Stream gauge installation at Allen Brook

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Indian Brook stream gauge

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Stevens Brook—Rather typical gauge installation

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Sunderland Brook stream gauge

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Weir plates at Munroe Brook

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Weir plate at Morehouse Brook

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Repairing old USGS weir at Englesby Brook

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Written deliverables during project start up

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2017 Monitoring Year in Review: Tasks

Discharge measurements

Annual gauge elevation survey

Calibrated tipping bucket rain gauges

Routine maintenance (approximately monthly)• Timelapse camera downloads and battery replacement• Staff gauge readings and pressure transducer calibration• Desiccant replacement• Cleared debris from channel

Non-routine maintenance• Reed switch replacement on multiple tipping buckets• Munroe Brook pressure transducer replacement (kinked cable)• Englesby Brook sediment (raised pressure transducer and installed snorkel)• Rugg Brook pressure transducer installed lower (exposed)• Battery swaps at Potash Brook (winter)• Beaver discouragement

Data management, including QA/correction of raw rainfall and stage data

Web site hosting

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Potash Brook in winter—Timelapse camera image

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Wading discharge measurement at Munroe Brook March 28, 2017

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High flow discharge measurement at Indian Brook using SonTek RiverSurveyor S5

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Low flow discharge measurement at Englesby Brook using collapsible cutthroat flume

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Low flow discharge measurement at Morehouse Brook using volumetric method

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Low flow discharge measurement at Munroe Brook using volumetric method

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Low flow discharge measurement at Allen Brook using continuous rate salt addition

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Discharge measurements

Allen Brook

Date Time Method Staff Stage Flow (cfs)

8/12/2016 11:35 CRA 0.65 0.04

9/28/2016 14:45 CRA 0.73 0.15

10/3/2017 10:15 Pygmy 0.84 0.22

10/31/2016 10:00 Pygmy 0.96 1.01

11/4/2016 15:30 Pygmy 1.11 2.37

11/1/2017 16:30 AA 1.30 5.54

10/31/2017 16:45 AA 1.44 8.59

10/31/2017 7:50 AA 1.54 14.28

1/4/2017 10:30 AA 1.63 17.67

10/30/2017 9:55 AA 1.9 34.99

2/26/2017 13:40 AA 2.32 80.99

4/7/2017 9:30 S5 2.72 114.88

6/30/2017 8:50 S5 3.6 320.31

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2017 Monitoring Year in ReviewGood Bad

No major instrument damage or dislocation during ice out and high flows

Tipping bucket reed switches needed replacement, with some loss of data

No vandalism Twisted or kinked pressure transducer cable at Munroe Brook resulted in poor stage measurement in the early spring

Conditions allowed reinstallation of pressure transducers in late February and ice cleared out rather early

Too slow to remove sediment at EnglesbyBrook, resulting in dampening of hydrograph peaks between May 25 and July 12, 2017

Good data “up time” (>99%) The water level at the Rugg Brook gauge fell below the pressure transducer in August, resulting in a several days of invalid data. The conduit was repositioned at a lower elevation

Weir plates installed at Munroe Brook and Morehouse Brook performed as intended and repairs to the Englesby Brook weir held

The pressure transducer at the Morehouse Brook gauge was destroyed when we attempted to remove it in December

Discharge measurements generally successful through spring

Relatively few problems with backwater conditions created by beavers and debris jams

Beavers created backwater conditions at Sunderland and Stevens Brooks for short periods

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Beaver at Sunderland Brook gauge, caught in the act

Dams found in May and November, 2017

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Modification at Englesby Brook gauge, July 12, 2017

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2017 Monitoring Year in Review—Stage comparisons

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Stage comparisons, Englesby Brook

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PRISM 800-m precipitation grid in Chittenden County

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What we are planning to do differently in 2018

MeasurementsDevelop electronic field form for staff gauge readings and maintenance activitiesPerform gauge surveys early in springPerform tipping bucket calibrations in springPlace a bottomless bucket around staff gauges for better readings under turbulent conditions

Data management/ReportingTimely review of timelapse photographs to identify deviations from recorded stageComplete stage-discharge ratings for all sites by summerFinalize daily mean flow estimation method in winter conditions2017 annual report

MaintenanceRoutine flushing of pressure transducer conduits to remove sedimentRepositioning timelapse cameras at certain stationsCleaning staff plates on every maintenance visitClose watch for beaver activity at known trouble spotsMove a solar panel at Potash Brook to increase solar exposure

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MS4 Flow Monitoring Website

Flow gages:http://vt-ms4-flow.stone-env.com/FlowDev/index.html

Standalone rainfall gages:http://vt-ms4-flow.stone-env.com/Precip/index.html#