01589352 - Gwynns Falls at Washington Blvd. at Baltimore, Md.

Location - Lat. 39° 16' 15", long. 76° 38' 54", Baltimore City, Hydrologic Unit 02060003, on left bank at Carroll Park Municipal Golf Course, 350 feet upstream of bridge on Washington Boulevard, 0.9 miles northwest of Morrell Park, and approximately 1.6 miles upstream from mouth.

Gaging station may be reached from the intersection I-695 and I-95 (near Rosedale) as follows:

Parking, on left bank

Follow I-95 Southbound through the Fort McHenry Tunnel Get off at Exit 50A-B (Caton Avenue Exit) On Caton Avenue exit ramp, take left fork and follow jug handle to merge onto Caton Avenue southbound. Follow Caton Avenue southbound approximately 0.7 miles to 3rd traffic light. At 3rd light, make left onto Washington Boulevard. Follow Washington Boulevard for approximately 1.3 miles. Just beyond the I-95 overpass, turn left into the entrance for the Carroll Park Municipal Golf Course. Bear left on entrance road, and park vehicle in grass area opposite the golf course. Gage is on the left bank at the edge of the tree line, approximately 350 feet upstream of bridge on Washington Boulevard. See map for route to gage.

Establishment - October 27, 1998.

Drainage Area - 65.9 square miles (measured on USGS topographic maps).

Datum of Gage -

Orfice conduit (on right) from left bank

Gage - Equipment is housed in a 30"x 30" x 12" galvanized rainproof electrical box with pulloff front. A gas-purge line is carried down to the stream under the upper embankment and under the asphalt path. The gas line then surfaces and is carried along the face of the gabion baskets lining the lower bank. At the gage and under the upper embankment, the gas line is run through combinations of 2" PVC pipe and 1" flexible plastic tubing. Along the lower bank, the gas line is housed in a combination of 2" galvanized pipe and 1" flexible plastic tubing. The line is carried to a standard 2" orifice fitting at the waters edge.

Pertinent elevations:	Gage Height (feet)
Base of right shelter support (ground)	21.51
Bottom of gage shelter (right side)	24.77
Top of gage shelter (right side)	27.27
Top of right shelter support (6x6)	27.32

Equipment shelf

Equipment - Sutron 8400 electronic stage recorder (15 min. scan interval), with stage kit.

Staff gage

Outside staff gage (00.00-2.52) attached to the streamward face of 6" x 6" pressure treated timber.

A standard USGS 2" x 1.43 ft galvanized crest-stage gage is attached to the shoreward face of the 6" x 6" pressure treated timber.

Pertinent elevations:	Gage Height (feet)
CSG (base cap)	1.34
CSG (length of stick)	--
Maximum recordable stage	--

History

1. No continous recording gage operated by USGS at this site previously.

Vertical Controls

[BM = Bench Mark; RM = Reference Mark; RP = Reference Point]
RM-1	Chiseled square in top of rock outcrop on right bank 60 ft upstream from weir plate near right edge of water. Elevation, 7.968 ft (gage datum).
RP-1	Top of instrument shelf at 3" pipe. Elevation, 3.262 ft (gage datum).

Looking upstream from gage Looking downstream

Channel - The channel is relatively straight, steep and confined above and below the gage with insignificant overflow. The streambed is essentially gravel, cobbles and rock outcrops and is fairly stable.

Control

Control - The low and medium water control is a triple V-notch aluminium weir plate (1/4" x 24" x 8’ ft) with symmetrical 1-ft wide x 0.50 ft deep, 90° V-notches secured in concrete; total design capacity, approximately 1.3 cfs +/-.

Wading measurement Bridge measurement

Discharge Measurements - Good measurements can be made at extremely low stages by volumetric means. At higher stages, channel improvements can be made 25 ft upstream to produce satisfactory results.

Floods - Flood of July 1, 1984 reached a stage of 2.19 feet, gage datum. Flood of August 20, 1999 reached a stage of 1.97 feet, gage datum.

Point of Zero Flow - 1.043 feet, gage datum (in right notch, based on levels from January 7, 1983).

Winter Records - Stage-discharge relation affected by ice at times during extensive cold periods.

Regulation - None.

Diversion - None.

Accuracy - Good records should be obtained.

Cooperation - Baltimore Ecosystem Study, Long-Term Ecological Research. University of Maryland, Baltimore County.

Photographs - See station files.