Initially fed by waters from the Lehigh River, the canal winds its way south along the Delaware River. The canal has 24 locks that, at one time, raised and lowered the water level 165 feet. It is the most intact tow path canal in the United States. Fish ladders with a window for viewing is just one of the many sights along the canal.
Residential development is encroaching in many areas along the canal and with that, sedimentation from stormwater runoff has reduced the canal's water depth from 5 feet to less that 1 foot in some places. Other land uses, such as heavy industry and landfills, have also impacted on the Canal. The Delaware Canal Master Plan was developed in an attempt to, among other things, regulate some of the land uses that are negatively impacting on the canal and park.
The Delaware Canal Park serves as a wildlife habitat and an area of natural beauty. On a recent Riverkeeper field trip near Tullytown, canal enthusiasts noted that the wooded canal corridor and neighboring Martins Creek had a buffering effect on the surrounding industrialized area.
Riverkeeper has a volunteer monitoring site on the Delaware Canal in Morrisville. Fred Gusz, a Riverkeeper volunteer, tests the water twice a month for basic water quality parameters. He also records stream conditions, sightings of flora and fauna and any observations of pollution or other threats. This information is recorded in the Riverkeeper Citizens's Database and distributed to environmental agencies responsible for stream protection and is available to local residents and all decision makers. The goal of Riverkeeper is to ensure that the Delaware River and every tributary stream of the watershed is actively protected by local residents. To that end, Riverkeeper, in cooperation with local grass-roots organizations with similar goals, encourages citizens to get involved in municipal land use decision-making, sponsors stream watch training workshops, and assists local groups to actively work on local stream protection projects.
| Length: | 60 miles |
| Watershed Area: | 0.68 Square Miles |
| Headwaters: | Easton, Pa. |
| Significant Tributaries: | Erwinna Creek Indian Rock Creek (Nockamixon Cliffs) Johnson Creek (Erwinna) Mine Spring (Upper Black Eddy) Silver Creek (Yardley) unnamed tributary (Bowman's Hill) unnamed tributary (Smithtown) |
| Land Use: | Four types of environment lie adjacent to the canal and the state park: (1) Rural (predominately open space and farmland), (2) Suburban (low-density residential land uses), (3) Village (more intense residential and commercial uses) (4) Urban (intense residential, commercial and industrial uses)--(Delaware Canal Master Plan). |
| Municipalities: | Bristol Brownsburg Centre Bridge Easton Erwinna Kintnersville Lodi Lumberville Monroe Morrisville Narrowsville New Hope Point Pleasant Raubsville Riegelsville Smithtown Taylorsville Tullytown Upper Black Eddy Yardley Uhlerstown |
Non-point Source Pollution:
In addition to Riverkeeper's field-gathered data discussed below, the water quality of the Canal is poor, primarily due to siltation and erosion from surrounding developments, large waterfowl population, highway runoff from Routes 611 and 32, and organic waste from leaking septic systems.
Point Source Pollution:
Chevron USA(*) is a permitted discharger for an underground tank clean-up, and does not appear to have a significant impact on the water quality.
RIVERKEEPER NETWORK DATA SUMMARY
Delaware Canal Monitoring Station:
East Maple Street Bridge, Morrisville.
Parameter Range Mean
pH: 6.2 - 7.5 6.9
Nitrates: 0.40 - 4.40 mg/L 1.20 mg/L
Phosphate: 0.1 - 0.8 mg/L 0.2 mg/L
Dissolved Oxygen (DO): 3.0 - 14.1 mg/L 7.6 mg/L
DO Saturation: 32.5 - 117.5% 68.6%
(sampling period: May, 1992 - May, 1993)
pH
The pH of natural waters is an important general water quality indicator because pH is a major factor affecting most chemical and biological reactions. The pH observed in water is determined by a number of complex interactions and provides an overall measure of the intensity of the various acid/base interactions which are occurring. For example, the geology of an area, including soil type, and the increasingly acidic precipitation (acid rain) can have a significant affect on the pH reading.
The pH scale ranges from 1 to 14 standard units. A pH of 7 indicates neutral conditions, while waters with a pH less than 7 are acidic and those with pH values greater than 7 are basic. Since pH is expressed on a logarithmic scale, each 1 unit change in pH represents ten-fold increase or decrease in hydrogen ion concentrations. Therefore, a pH of 6 would be 10 times more acidic than a pH of 7 and 100 times more acidic than a pH of 8. The pH of normal rainwater (containing no pollutants) is about 5.6. As the rainwater travels over and through rocks and soil, chemical reactions with minerals affect the pH and buffering capacity of the water.
pH readings at the Delaware Canal varied through-out this sampling period. The average reading, however, indicates a neutral pH balance.
Nitrate (NO3-N)
Nitrate is the principal form of nitrogen in most surface waters, but high concentrations of nitrate (> 4 ppm) may reflect unsanitary conditions because of human and animal wastes are major sources of nitrate.
Nitrate readings at the Delaware Canal are not excessively high and similar to readings from neighboring streams monitored by Riverkeeper.
Phosphate (PO4)
Phosphorous is a natural and essential nutrient and is often the factor limiting additional growth of aquatic organisms. However, excessive phosphorous concentrations can be detrimental to surface water quality. Typical external sources of phosphorus are fertilizer, septic leachate, sewage effluent, detergents and soaps, and particulate material transported by stormwater.
Phosphate readings at the Delaware Canal varied considerably over the sampling period. They were, however, not excessively high and similar to neighboring streams monitored by Riverkeeper.
Dissolved Oxygen
The dissolved oxygen (DO) concentration of a river is an important indicator of the overall "health" of the system. Oxygen is essential for the survival of fish and many other aquatic organisms. The amount of oxygen which can dissolve in water is subject to fluctuation in temperature, photosynthetic activity, and stream flow (low flow and temperatures are a common cause of low oxygen readings during the summer months). Respiration processes, oxidation of inorganic wastes, and the decomposition of organic matter deplete oxygen, while photosynthesis and re-aeration by contact with the atmosphere increase oxygen concentrations in water. Most desirable aquatic organisms require a DO concentration of 4.0 ppm or greater for long-term survival.
The Delaware Canal's dissolved oxygen mean reading was the lowest of any other monitoring site in this area. One reading was 3.0 ppm, which can result in fish kills. Considering the low flow conditions that exist in the Canal, low dissolved oxygen readings are not surprising. Also, reports of leaky septic systems may also contribute to reduced oxygen levels.
Dissolved Oxygen Saturation
Dissolved oxygen can also be expressed in percent of saturation. The amount of oxygen can dissolve in water decreases with increasing temperature and dissolved solids concentration. For this reason alone, dissolved oxygen concentrations in surface waters usually increase significantly during the winter months. By eliminating the seasonal variations caused by temperature, dissolved oxygen saturation can provide a better comparison of dissolved oxygen in water between sampling dates than dissolved oxygen concentrations.
Rivers with dissolved oxygen saturations of 90% or greater are considered healthy. Unless the waters are supersaturated due to cultural eutrophication (enrichment of surface water as a result of human impacts). below 90% saturation may have large amounts of oxygen demand materials (organic waste).
The dissolved oxygen saturation mean reading, which typically corresponds with dissolved oxygen levels, was the second lowest of all estuary sites, almost as bad as the Murderkill River, Delaware.
Observations and Comments
Volunteers observe wildlife, weather conditions, and general water and habitat conditions. At the Delaware Canal, a large waterfowl population was noted and that they are well fed by area residents. Sightings also included Great Blue and Green Herons and Great Horned Owls. While no otters have been seen on Otter Creek, there was a sighting on the Delaware River near Yardley. Oily runoff was also observed several times coming from nearby storm drains.
The volunteers have confirmed what you already know -- Delaware Canal has its problems, but is still a viable ecosystem worth protecting and restoring. It supports wildlife and offers tranquility and recreation. The Canal needs continued monitoring so that field tested stream conditions can be used as input to devise strategies for improving water quality and streamside habitat. Continued monitoring is also important to ensure that problems are identifies early and corrected before significant degradation occurs.
For Additional Information:
Riverkeeper Fact Sheets are updated as new information becomes available. If you have information on Delaware Canal, please call the Delaware Riverkeeper Network at (609) 854-5108.