Frankford Creek
Previous Projects for Improvement
Up to 1946
SOURCE: Report on Flood Control, Frankford Creek, City of Philadelphia, Pennsylvania. Knappen Engineering Company, 280 Madison Avenue, New York 16, N.Y. October 1947. Pages 27-31
General Plan.
Excepting the establishment of confirmed channel lines, there bas been no authorized plan for coordinated improvement of the entire length of Frankford Creek. Dredging operations undertaken by the City were of an emergency nature to relieve particular sections of the channel that were choked with debris and sediment. The benefits from much operations were short lived because of the continued abuses already discussed.
Changes in Alignment.
There is evidence that, over a period of 40 to 50 years, there have been several changes in alignment of portions of the [Page 28] channel of Frankford Creek. The most recent change was in 1934, when a cutoff was made across the former horseshoe bend above Bridge Street. This would have been a considerable improvement in the lower reaches except for the fact that the Bridge Street bridge opening was a bottleneck in itself ( See Plate 11A ) and therefore nullified to some extent the gains made as a result of the cut-off.
In the tidal reach below the main line of the Pennsylvania Railroad about 2,500 feet of channel was relocated to avoid a bridge crossing for the Pennsylvania-Reading Seashore Lines leading to New Jersey (See Plate 9). This change, which was believed to have been made about 40 years ago, had little beneficial effect on the flood carrying capacity of the channel. In fact the construction of the railroad fill blocked off a portion of the valley storage that was available under natural conditions for the reduction of flood peak discharges.
Between Kensington Avenue and Frankford Avenue the channel formerly swung in a wide curve to the east and crossed the line of Frankford Avenue 400 feet from the present location. Removal of this bend reduced the length of the channel and probably improved flow conditions. The change was made about 45 years [1902] ago.
The present channel paralleling Adams Avenue between Leiper and Church Streets was formerly about 100 feet further east. The old channel was filled in to make room for the extension of Adams Avenue.
The above-mentioned changes in alignment, except that above Bridge Street, were not intended primarily as channel improvements. They were made to facilitate development of the City and its utilities, and as that development went forward along the relocated channel the resulting structures had a very adverse effect on the flood carrying capacity of the channel.
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Levee Protection.
The frequent overbank flooding Frankford Creek created a demand on the part of property owners for relief and protection. As a result the City initiated several projects in the period 1931-42 for dredging reaches above the former Navigation channel. The sand and gravel excavated from the creek bottom were spoiled along the banks in low levees particularly at low places between buildings (See Plate 3A). Following the floods of 1930-33, several industrial plants took steps to protect themselves with levees. These levees are located immediately above Torresdale Avenue on the east bank and above Wingohocking Street on both banks.
All the existing levees on Frankford Creek constitute an emergency type of protection and are not considered a permanent solution to the flood problem. For example, the levees are not based on a coordinated hydraulic design and although they may appear to exclude the water at one point the chances are that flood waters may get behind them through a vulnerable point upstream. Furthermore, the levees are made of pervious material on steep and unprotected slopes with the result that they are gradually decreasing in effective height. The final objection to them is that they do not increase the channel capacity, but merely raise the water level and increase backwater conditions in the sewers. When they are overtopped, as they eventually will be, the property owners will suffer more damage than before because of a false sense of security.
Removal of Encroachments.
Except for the encroachments adjacent to the cut-off made above Bridge Street in 1934, no attempt to remove encroachments has been effective. There has been some improvement in encroachment conditions, as mentioned on page 14, but this improvement has been accidental and not as a result of deliberate efforts on the part of property owners. Buildings that were eliminated from the flood plain were torn down because [Page 30] it was in the best interests of the owners to remove them.
The old dam above Wingohocking Street was removed by the owners in July 1933 after it had been seriously damaged by floods (See Plate 3). This change had considerable benefit in the immediate vicinity in that overbank flooding through headraces was eliminated. However, the filling in of both banks that took place after the dam was removed decreased the effective width of the channel between the dam site and Wingohocking street (See Plate 5B.
Dredging to Increase Flood Capacity.
Projects by the City to improve the capacity of the channel for flood flows were previously mentioned under "Levee Protection". These dredging operations were of an emergency nature to relieve conditions where portions of the channel were filling in. Without a comprehensive plan for lowering the entire channel and for controlling sedimentation, bank erosion and dumping, such dredging operations would have to be repeated from time to time.
Dredging to Improve Navigation.
In accordance with Congressional authorization in 1882 a sum of $10,000 was expended in dredging a channel 50 feet wide and 7 feet deep from the mouth of Frankford Creek to the horseshoe bend above Bridge Street. A total of 35,200 cubic yards of material was removed. The project was to have been extended to Frankford Avenue with depths decreasing to 3 feet at the upper end but the Chief of Engineers, U. S. Army, recommended in 1884 that no further appropriation be made. Although reports on the improvement of Frankford Creek were made from time to time no further work was ever undertaken by the Federal Government.
The Department of Wharves, Docks and Ferries later took up the problem of maintaining a navigable channel to Margaret Street. In the period 1915-29 the channel was dredged 10 times and a total of 270,000 cubic yards of material was removed. The channel is again filled in and except at the mouth, most [page 31] of the bottom is exposed at low tide.