A small Schuylkill River tributary called Dobson's Run once
drained a watershed consisting of parts of East Falls, Nicetown and
Germantown. Like many such natural streams, in Philadelphia and
most other cities in the world, it was systematically buried in a
sewer beginning in the 1890s, and now appears only on the
Philadelphia Water Department's sewer maps. Old city maps, however,
still show this small stream, which entered the Schuylkill on the
east side, north of Laurel Hill Cemetery and just about where the
Twin Bridges of Roosevelt Boulevard now stand.
Dobson's Run had two branches. One had its source near the Queen
Lane railroad station in Germantown, and the other branch began
near the old Nicetown Steel Works in the city's Nicetown
neighborhood. These two small streams joined about 1-¾ miles east
of the Schuylkill and eventually flowed through the property of
John and James Dobson, who owned and operated many textile mills in
the Philadelphia area. The Dobson mill east of Ridge Avenue in
"Falls Village" (as East Falls was originally called) used the
water from Dobson's Run for industrial processes and for waste
disposal. This mill was one of the largest carpet factories in the
world in the latter decades of the 19th century.
To provide water for the mill, the natural stream was dammed
above the Dobson complex, backing up a large pond behind the dam.
Some of the water from this pond was diverted through the plant in
a number of small canals or ditches, called mill races. Below the
factory complex the races carried the water--tainted with chemicals
and wastes from various carpet-making processes--back into the
natural stream, which flowed into the Schuylkill River in this
polluted state. One observer in 1882 said the sand and gravel at
the mouth of the stream was stained with dyes from the Dobson
factory.
Since the stream was polluting the "Fairmount Pool" (the stretch
of the Schuylkill River above the Fairmount Dam, which was a major
source of drinking water for the City) several attempts were made
over the years to get the Dobson's and other factory owners to stop
dumping their wastes into it. One such lawsuit, filed by the
Fairmount Park Commission in 1880, alleged that discharges from the
mills were polluting the city's water supply. In response, the
expert hired by the Dobsons, a Penn professor, stated that Dobson's
Run was contaminated by ordinary sewage "in far larger proportion
than the impurities which are added to it as a result of the
manufacturing operations carried on along its bank."
Though this hired expert was clearly biased in favor of the
Dobsons, he was probably correct in his assessment. Sewers and
outhouses from the Dobson's mill, from other businesses, and from
the expanding residential neighborhoods upstream, all emptied their
wastes into the creek, causing a serious health nuisance. This was
a problem not only in East Falls, but all along the stretch of the
Schuylkill River above the Fairmount Water Works. Protection of the
city's water supply from such pollution was the main reason that
Fairmount Park was created just after the Civil War. This
protection became even more important as the population exploded in
the second half of the 19th century and the city added water supply
pumping stations at Spring Garden, Belmont, Queen Lane and
Shawmont.
The ultimate solution to the problem was to put Dobson's Run
into a large, separate, storm sewer, to carry the stream flow and
any stormwater directly into the Schuylkill river. Sewage from
households and businesses along with wastes from industries in the
small valley were captured in a smaller, separate, sanitary sewer
before the sewage and industrial wastes could reach Dobson's Run.
The sanitary sewer connected with an intercepting sewer that
paralleled the Schuylkill River, capturing all the sewage flow from
Shawmont downstream to Fairmount, dumping it into the river below
the Fairmount Dam. This work began in the early 1880s and, in the
valley of Dobson's run, continued at least until 1912. The
interceptor also carried all of the sewage from the Wissahickon
Creek valley, as well, including rapidly growing portions of
Chestnut Hill, Mt. Airy, and Germantown, whose development was
spurred, in part, by construction of the Chestnut Hill branch of
the Pennsylvania Railroad, completed in 1884.
CURRENT PROJECT
In natural areas, rainfall that does not infiltrate (soak into)
the ground runs off on the surface, finally making its way into the
nearest stream. In urban areas, where many surfaces such as
rooftops, streets, sidewalks and parking lots are "impervious" to
water, rainfall has little opportunity to soak into the ground, and
instead, most of it flows through storm drains and downspouts to
sewers.
Street flooding in urban areas occurs when the sewer system is
unable to carry off this flow, causing the water to back up onto
the surface. In most cases, the fix for this problem is simple and
cheap: clear away the leaves and debris that often clog storm
drains and the water drains away. In some cases, however, as in the
area served by the Dobson's Run Sewer, the sewers are not large
enough to carry away the stormwater, which backs up above the storm
drain during heavy rains. In such cases, repeated flooding often
occurs in low points in the neighborhood.
Relief sewers, to provide additional capacity for the
stormwater, are often necessary in these areas, and many have been
built in the city in the past 100 years.The Dobson's Run Stormwater
Relief Sewer, to be built upstream of the flood-prone areas, will
increase the drainage capacity of the sewers in the watershed. By
capturing part of the storm flow and carry it directly to the
Schuylkill River, it should relieve flooding in the valley of the
former Dobson's Run.
BYOP
No hints as this is too easy!