01589300 - Gwynns Falls at Villa Nova, Md.

Location - Lat. 39�20�45�, long. 76�44�01�, Baltimore County, Hydrologic Unit 02060003, on right bank 300 ft downstream from bridge on Essex Road, 300 ft north of State Highway 26 (Liberty Road), in Villa Nova, 1.1 mi west of Baltimore City limits, and 11.5 mi upstream from mouth.

Station can be reached from interchange of Md. 26 (Liberty Rd.) and I-695 (Beltway) as follows:

Parking, looking east from gage

Proceed eastbound on Md. 26, 0.7 mile. Turn left 300 ft beyond the traffic light at the intersection of Md. 26 and Essex Rd. into the rear driveway of Waggoner's Mobil Station and proceed 250 ft to gage at rear of property. See map for route to gage.

Establishment - February 7, 1957, at site of old Essex Road bridge; at present site since Aug. 27, 1963 to June 22, 1972 when gage was destroyed by flood. Reestablished as permanent gage at present site Sept. 24, 1973. Gage discontinued in October 1988. Re-established in October 1, 1996.

Drainage Area - 32.5 square miles (measured on USGS topographic maps).

Datum of Gage - 361.32 feet above National Geodetic Vertical Datum of 1929 (NGVD).

Intake and static tube, from right bank

Gage - 5 ft. square steel pre-fab house set on a concrete collar on top of a 42-inch diameter corrugated metal pipe set in concrete. Intakes are two 2-inch galvanized steel pipes, both equipped with gate valves in conjunction with a 35-gallon holding tank. No well door. Well accessible by 14 ft. ladder bolted to inside of corrugated metal pipe section.

Pertinent elevations:	Gage Height (feet)
Floor of well	-1.0
Top of lower intake	-0.4
Top of upper intake	2.0
Top of instrument shelf	15.0
Top of house	20.0
Instrument shelf	20.4

Equipment shelf

Equipment - Sutron 8400 digital data recorder (15 min. scan interval) with stage kit.

Staff gage

Lower outside (0.0 - 3.3 ft) is a 4" x6" treated post set in reinforced concrete 20 ft streamward from gage.

A standard USGS 2" x 7 ft galvanized pipe crest-stage gage is bolted to the shoreward face of the gage house.

Pertinent elevations:	Gage Height (feet)
Lower CSG (base cap)	--
Lower CSG (length of stick)	--
Maximum recordable stage	14.7
Point of zero flow	-0.3

History

1. Recording gage at old bridge on Essex Road 300 ft upstream at same datum Feb. 7, 1957 to Aug. 27, 1963.
2. Recording gage at present site and same datum Aug. 1963 to June 22, 1972 (gage destroyed by flood of June 22, 1972).
3. No recording gage (R.P.) June 27, 1972 to Oct. 25, 1972 (Steel tape read twice daily by local observer).
4. Temporary recording gage installed on new Essex Road Bridge 300 ft upstream at same datum. Oct. 25, 1972 to Sept. 21, 1973.
5. New permanent recording gage installed at site 300 ft downstream from Essex Rd. bridge at same datum, Sept. 21, 1973 to September 30, 1988. Gage re-established in same location October, 1996.

Vertical Controls

[BM = Bench Mark; RM = Reference Mark; RP = Reference Point]
RM-8	Top of bolt, the southwestern most of 4-bolts in base plate of light pole near Liberty Rd. at entrance to service driveway to rear of Wagoner's garage and to gage; elevation 13.287 ft. gage datum.
RM-9	Chiseled square on right end of downstream handrail of bridge on Essex Rd. above construction template stamped 1963 and 1.8 ft above sidewalk; elevation 16.011 ft, gage datum.
RM-10	Brass tablet set in top of new lower O.G. pier; elevation 4.426 ft, gage datum.
RM-11	Chiseled square on upstream streamward corner of gage; elevation, 11.458 ft, gage datum.
RM-12	Bolt set in telephone pole on south side of gage: elevation 13.574 ft gage datum.
RP-2 (horizontal)	Chisel mark in downstream face of aluminum handrail strut near left center portion of left bridge opening; elevation 16.435 ft. gage datum.
RP-3	Top of 1/2" bolt head set horizontally in front facing of instrument shelf; elevation 14.728 ft, gage datum.

Last levels run on 4/3/97.

Looking upstream from gage Looking downstream

Channel - Channel is improved and straight for 150 ft below and 500 ft above gage and varies in width from 100 ft at the bridge to 60 ft at gage to 45 ft at the low water control riffles 150 ft below the gage. Channel improvements were completed in Aug. 1973 by private contractor in conjunction with Baltimore County. All embankments and slopes are seeded in the reach of channel improvements. In vicinity of gage, left bank overflows at 6 ft and right bank overflows extensively at 11 ft. Bed of stream is composed mainly of sand and gravel with some rocks and is fairly uniform and fairly permanent.

Control

Control - Low water control is a rock and boulder riffle 150 ft below gage and fairly permanent. Channel control at medium and high stages.

Wading measurement Bridge measurement

Discharge Measurements - For stages up to 3.5 ft, good wading measurements can be made in vicinity of the gage or near the downstream side of the bridge upstream. At higher stages, measurements may be made from Essex Road bridge. Bridge is marked off in 5-foot intervals. Extremely high stages may be measured from the Liberty Rd. bridge.

Floods - Flood of June 22, 1972 reached a peak stage of 21.50 feet, gage datum, with a discharge 16200 cfs.

Point of Zero Flow - Varies due to shifting rocks and boulders in control riffle.

Winter Records - Stage-discharge relation affected by ice at times during winter months.

Regulation - Slight diurnal fluctuation at times from unknown source.

Diversion - Slight diurnal fluctuation at times from unknown source.

Accuracy - Good records should be obtained.

Cooperation - Baltimore County Department of Environmental Protection and Resource Management.

Photographs - See station files.