Plum Island Ecosystems LTER Database

Acceptance and utilization of LTER data requires that:

(1) The Principal Investigator be sent a notice stating reasons for acquiring any data and a description of the publication intentions.
(2) The Principal Investigator of the data set be sent a copy of the report or manuscript prior to submission and be adequately cited in any resultant publications.
(3) A copy of any resultant publications should be sent to:

Principal Investigator
Ecosystems Center
Marine Biological Laboratory
7 MBL St.
Woods Hole, MA 02543

Dataset URLs:METADATA: HTML, Rich Text, XML(EML compliant)
DATA: Comma Delimited, Excel file with Metadata and data
Dataset ID:WAT-YSI-Urban-2007.02
Dataset Title:Year 2007, 10 minute measurements of stage in a small headwater stream draining a highly suburban catchment (72% residential), Saw Mill Brook, Burlington, MA.
Investigator 1: 
First Name:Wilfred
Last Name:Wollheim
Address line 1:Morse Hall
Address line 2:UNH
Address line 3:
Zip Code:03824
Associate Investigators:
Keywords:PIE LTER, disturbance, Saw Mill Brook, suburban, discharge, water temperature, water stage.
Abstract:Year 2007, continuous measurements, every 10 minutes, were made of depth and stream temperature in a small headwater stream, Saw Mill Brook, Burlington, MA, draining a highly suburban catchment (72% residential). Discharge is determined from stage using discharge vs stage regressions.
Contact: Plum Island Ecosystems LTER Information Manager
The Ecosystems Center
Marine Biological Lab
7 MBL St
Woods Hole, MA 02543
Phone (508) 289 7485
Online URL:
Data File URL
Data File Name WAT-YSI-Urban-2007
Beginning Date 1/1/2007
End Date 12/31/2007
Number of Data Records 41871
Other Files to Reference All in the YSI series.
Availability Status Type 1
Quality Control Information
Maintenance Description Periodic with improvement of rating curve, particularly as more high discharge events are incorporated.
Log of Changes: Version 01created January 2010
Version 02: February 14, 2014, data and metadata updated to comply with importation to Drupal and LTER PASTA. Used MarcrosExportEML_HTML (working)pie_excel2007_Sep2013.xlsm 9/30/13 02:57 PM for QA/QC to EML 2.1.0
Geographic Description Watershed water collection and stream characterization site for Saw Mill Brook (urban landuse), Burlington, MA  
Location Bounding Box    
West Bounding Coordinate    
East Bounding Coordinate    
North Bounding Coordinate    
South Bounding Coordinate    
OR if single point location    
Latitude 42.5236  
Longitude -71.185  
Taxonomic Protocols
Organisms studied
Methods:Depth and water temperature were measured using a HOBO data logger deployed in a stilling well.

Depths are corrected for barometric pressure changes using readings in an additional HOBO datalogger deployed at Marshview Farm. The HOBO is deployed in a a PVC tube, which was attached to ree-bar driven into the stream bed. The PVC tube has holes drilled to allow adequate water circulation.

ADDITIONAL RESEARCH LOCATION COORDINATES: In addition to the decimal degree coordinates given above, locations are also given here in Massachusetts State Plane coordinates. The stream is called SawMill Br. and is located in Burlington MA. Small amounts of forest remain (~14% in 1999), much of which is along the stream channel near the gaging site.

YSI-SB 225840 919310

Velocity measurements were made using a Marsh McBirney current meter. Discharge estimates in Saw Mill are based on a power rating curve that contains measurements up to a depth of 1 meter, which is above bankfull stage. Rating curve has an R2 of 0.96 using 24 measurements between 2001 and 2007. Rating curve has been standardized to HOBO_Depth to allow application of a single rating curve across years. All files in this series (2001-2007) are currently standardized to HOBO_depth.

The column Depth_Device is included when combining files from several years, over which several different devices were used to calculate depth. HOBO_Depth is the depth that is standardized across all measurement devices so that a single rating curve can be applied.

Velocity measurements were made using a Marsh McBirney current meter and starting in 2009 with a Sontek Flowtracker. Discharge estimates in Saw Mill are based on a power rating curve that contains measurements up to a stage depth of 1.2 meters, which is above bankfull stage. Rating curve has an R2 of 0.89 using 40 measurements between 2001 and 2009. The rating curve has not noticeably changed over the period. Prior to 2007, stage was measured with various other instruments (YSI, Sigma depth sonde, HOBO). All files in this series (2001-2009) are now standardized to HOBO depth. The rating curve is based on the standardized HOBO depth's (and actual HOBO depths since 2007).

Discharge rating curve :
Discharge (l/s) = 889.65*depth^5.8788
where depth is Adj_HOBO_Depth

Adj_Hobo_Depth is a corrected HOBO depth that represents the true hobo depth (StandardizedHoboDepths in previous years). We started having problems with sand accumulation in the stilling well, and following downloads, redeployment of the HOBO caused it to sit on top of the sand. Manual measurements of water depth were used to make the correction. Starting in 10/21/09, we plan on preventing this from happening any longer. The following corrections were applied:
1. 2006-07-26 - 2007-04-03: 0 m
2. 2007-04-03 - 2007-04-18: 0.035 m
3. 2007-04-18 - 2007-05-23: 0.055 m
4. 2007-05-23 - 2008-06-06: 0.072 m
3. 2008-06-06 - 2009-01-14: 0.0446 m
4. 2009-01-14 - 2009-10-21: 0.0957 m
5. 2009-10-21 - yyyy-mm-dd: 0

Adj_HOBO_Depth is equivalent to StandardizedHoboDepths in previous years.

Also, at times depth and discharge may be periodically erroneous due to leaf pack accumulation at a riffle downstream causing backup. We remove this whenever we visit the site. Generally we believe the depth error is on the order of 2-4 centemeters. The depth data have not been corrected for errors associated with temporary debris dams.

Data Table

Variable Name Variable Description Units Measurement Scale Code Information Number Type DateTime Format Missing Value Code Missing Value Code Explanation
Date date (yyyy-mm-dd)   datetime     yyyy-mm-dd NA NA = not available
Time time (hh:mm) 24 hour   datetime     hh:mm NA NA = not available
Temp water temperature (oC) celsius interval   real   NA NA = not available
HOBO_Depth stage height measured by HOBO (m) meter ratio   real   NA NA = not available
Adj_HOBO_Depth HOBO depth + CorrectionFactor (see methods) meter ratio   real   NA NA = not available
Device_Depth depth measurement device used to determine discharge   nominal YSI = YSI depth sonde | SIGMA = Sigma autosampler depth sonde | TEMP_HOBO = HOBO depth sonde deployed in temporary stilling well | HOBO = HOBO depth sonde deployed in permanent stilling well     NA NA = not available
Discharge discharge literPerSecond ratio   real   NA NA = not available