Manners Dam Run Watershed Liming Project
The Manners Dam Run Watershed was identified in the North Fork Watershed Assessment and Restoration plan
that was completed in 2006. Water samples showed that the water was adversely impacted by acid deposition. Low pH values were also
discovered in soil samples taken in the watershed, indicating that the soil had little capacity to buffer the acid rain before it
made its way into the stream. The Jefferson Conservation District and North Fork Watershed Association applied for and received a
Growing Greener Grant in the amount of $49,766.00. This purpose of this grant was to improve the 1.2 square miles of the Manners Dam
Watershed by directly dosing some areas with limestone sand and by spreading a variety of sizes of limestone on the forest floor,
this project aimed to increase the buffering capacity of the soil and in turn raise the pH of the water in Manners Run.
Beginning
in the Fall of 2007, lime was applied to the forest floor using a Franklin Pre-Hauler that was retrofitted with a five-ton lime hopper.
The Pre-Hauler is owned by the Pennsylvania Game Commission (PGC) and was operated by Game Commission employees as in-kind services.
With this assistance from PGC, the cost to apply the lime was lessened ultimately allowing the group to apply 2,028 tons of lime to
the watershed instead of the originally planned 508 tons of lime.
One of the goals of this project
was to apply approximately 2 tons per acre to the watershed. Some areas were inaccessible to the liming machine, however, many areas
benefited from an extra amount of lime being applied. For this reason, some areas may have received up to 6 tons of lime per acre
while the other areas received approximately 3 tons per acre.
Water samples were taken approximately
every other month through the course of the grant period. Soil samples were taken twice and vegetation was analyzed four times.
The
ultimate goal of this project was to increase the pH of Manners Run in order to restore the water to a fishable resource. The purpose
of the watershed liming was to add buffering capacity to the forest soils so that acid precipitation could acquire alkalinity as it
percolated through the soil. The graphs of pH values at the four water sampling sites indicate an overall gradual increase in pH over
the course of the project. Man-1 was the sampling location farthest downstream of where the liming took place. Flow of water was greatest
at this sampling location. This is also the location that showed the most obvious improvement in pH. Man-4 was the farthest in the
headwaters of Manners Run Watershed of all the sampling locations. This vicinity also had the least amount of land liming. Early in
the project, a significant amount of lime was applied in or near the stream itself. This would explain the initial spike in pH followed
by a drop at the next several sampling dates. Terrain in this area made it difficult to use the liming machine to spread the lime
on the forest floor. However, there is still a marked increase in pH.
Before the liming project began,
the Pennsylvania Fish and Boat Commission (PFBC) conducted an electro-fishing survey of an approximate 200 meter section of stream
located approximately 800 meters downstream of the impoundment. This occurred on 10/18/07. A total of nine Brook Trout (Salvelinus
fontinalis) were collected at this time, all of which were 125-150 millimeters in length. Pumpkinseeds (Lepomis gibbosus) were also
collected at this time. On 9/8/08, the PFBC returned to conduct a second electro-fishing survey of the same stretch of Manners Run.
This was approximately one year after liming began, but before the project was completed. This time three species of fish were identified:
Brook Trout, Blacknose Dace (Rhinichthys atratulus) and Creek Chub (Semotilus atromaculatus). Twenty-six trout were counted. This
was a significant increase in the number of trout from one year to the next. Another significant detail was that the trout ranged
in size from 50-200 mm, with 23 of the fish measuring 50-75 mm. The significance of this finding, according to the PFBC, is that reproduction
appears to be taking place in this stretch of stream. There was no evidence of trout reproduction during the pre-liming electro-fishing
survey.
To summarize, the gradual but consistent increase in water pH along with the discovery of potential
fish reproduction in Manners Run gives scientific evidence that the liming project has been a great success.
There
are a few specific reasons why this project has been so successful. First and foremost are the efforts of the North Fork Watershed
Association and the Pennsylvania Game Commission. Employees and volunteers of these two groups have contributed hundreds of hours
in-kind to the project as well as the PGC donating the use of heavy equipment to spread the lime in the watershed.
Another
reason for the success of the liming project was the results of the previously completed Swede Run Liming Project. While that project
was successful, it brought to light some deficiencies in the liming process. Limestone collector fines were used exclusively at Swede
Run. The p of lime were so small that they gave a more immediate increase il and water pH as they dissolved very quickly. For the
Manners Dam Project, it was decided to use a mixture of the collector fines and more coarse limestone sand. In a few instances, an
even coarser grain of limestone chips or rocks was utilized. The mixture of sizes of limestone allowed the project to have both an
immediate and a longer-lasting effect on the soil and water. Because of this, it is expected that the pH of the water will continue
to rise in the upcoming months and years and will remain at a constant pH for a much longer period of time.
With
this project, approximately 550 acres of land (forest and fields) were limed with a mixture of limestone collector fines and limestone
sand. The average pH of four sampling points before liming began was 4.41 and now averages 5.73. Fish reproduction was not occurring
pre-liming, but has been observed one year post-liming.
For more information on this project, contact
the Jefferson Conservation District or the North Fork Watershed Association at www.nfwatershed.org.