Frequently Asked Questions

Are BBQ Grills ready for member use?


We suggest bringing your own propane. There is often a tank in the propane grill and we try to keep it full and rotated (we have three tanks). You are welcome to use what may be in the tank, but cannot, of course guarantee there will be a full tank, so we advise bringing your own to be on the safe side.

The other grill is charcoal so also feel free to bring and use as you would any charcoal grill




Will the lake be treated for weeds?


What appear to be weeds in the spring are actually chara, an algal species, also known as stonewort. It is a cold water species growing throughout the early spring and late winter. It dies off when the water warms up in late May to mid-June (in 2020, around June 12th-15th). Most environmental contractors do not try to treat it as it dies off early and the contractors cannot provide a treatment efficacy guarantee because it is algae and not typical rooted, aquatic vegetation.

Our other typical weed issue is bladderwort and we treat that if needed but this weed has not been bad enough to treat the past few years. Bladderwort starts to grow in when the water warms up, usually in late May and early June. Rainfall and good flow through the lake helps to avoid a problem with Bladderwort.

With significant reason and experience, we are very cautious with treatments and use them sparingly and when truly needed during the worst cases as anything we do can often make the long-term problem worse. For bladderwort, the treatment is an aquatic herbicide called "Diquat" that must be applied and adhere directly to the plant material in the water column. If such treatment were applied at the wrong time, the dead vegetation would start to rot in the water, stink horribly and then sink to the bottom, creating even more bottom detritus, further fueling future growth. Treatments are a very delicate balancing act.

Also, please note that our lake is a damned branch of the Rancocas creek with significant water flow & movement, so treatments that might work in a small, stagnant pond without flow or displacement do not work the same way in the flowing water. One of the main underlying problems is the fertilizing of the lake water (nitrate overload) caused by lawn fertilizer run off. For this reason, we encourage our property owners to limit manicured lawns and opt instead for plantings indigenous to the area. The problem will get worse as more owners clear cut lots, plant lawns and continue to fertilize, which is necessary to keep grass flourishing in the sandy, nutrient-poor soil of our area, and it is not indigenous to our area. See this website for recommendations on New Jersey plants and landscaping design: https://www.jerseyyards.org/.

The two other issues we may see in the lake are filamentous algae which can be cyclical, and which we haven't seen in a few years, and lily pads. The specific treatment for the lily pads is a pelleted systemic that gets applied in late September and works through the fall and winter months to help control their growth. The lily pad treatment is typically 30-40% effective at best so it's also a constant battle in the shallow areas. We don’t actually want to eliminate all the lily pads because they provide necessary habitat for aquatic life and aren't an issue until they become invasive.

Shallow area shoreline maintenance during the annual lake lowering cycle can be beneficial in controlling weed growth. This entails removing plant-based growth (lily pad roots where invasive) and bottom debris as is reasonably possible and manageable.




What about those beavers gnawing on the trees?


Though we love both our trees and wildlife, Oakwood has experienced an increase in beaver population and consequent damage to trees since about 2008 that create an out-of-balance situation. Our lake is 22 acres, with much of the shoreline wooded. The damage has had serious consequences, including the branch of Haines creek rising behind Oakwood Drive because of clogged pipes. The two culvert pipes under Elm Drive have been clogged numerous times, which creates a flooding risk. Twice the pipes had to be cleared by Oakwood volunteers because no one else would do it from the Township or County.

We have experienced about 100 downed trees over the last five years all along the lake and beach. The beavers take trees down, or severely damage them quickly, often in just one night. We had 8-10 trees taken down at the beach/picnic area in 2020 alone and there are two trees damaged going around the curve from Oakwood to Cedar that we had to wrap in wire to discourage beaver access. Making it inhospitable for the beavers has been done for years by many in the neighborhood and general area and the population has multiplied since we first started seeing them, with only limited success.

​We are still seeking solutions, with the possibility of trapping and relocating the beavers




What are the rules for boating and fishing?


Boating and fishing is permitted by members in good standing with current year Oakwood Decals affixed prominently on each side of watercraft. Electric motors are permitted, but not gasoline-powered engines.

​All fishing is on a "catch and release" basis only. Native fish contribute to nutrient recycling and help maintain natural ecosystem processes when they live out their entire life cycle, from spawning to death, in the aquatic system. This practice provides an opportunity for increasing numbers of anglers to enjoy fishing and enjoy the sport.




Is there an Emergency Management Plan in case of excess rain?


Oliphant Lake is part of the larger waterway of the Rancocas Creek Basin, which eventually flows into the Delaware River. An official emergency plan was established as a result of the 2004 Flooding Event. (See details here).

​The plan established a chain of command and contact management system to coordinate actions among the various dam owners along the waterway. State, county and local emergency teams monitor water levels through USGS approved gages and determine when, or if, water flow should be adjusted by lowering our dam. Two of our trustees are contacts who receive any instructions accordingly. We are not permitted to adjust the water flow without authorization. There is a very specific sequence and timing to ensure a controlled response and avoidance of sudden surges of water in any area.




What’s that oil on the lake water?


We get inquiries each year during the warm weather about the “oil on the lake.” It is not motor oil from runoff surface water, it is not from a gas-powered motor boat nor sun tan oil. The NJDEP has come up with a definition of oily sheen vs. a naturally occurring sheen. The oily sheen from a petroleum product can't be broken, while sheen from natural occurrence can be broken into pieces by agitation.

The oily sheen we see on the lake surface is a natural, benign, by-product of the bacterial flora in the lake water and underlying soil. All bodies of surface water and soils have varying amounts of micro-organisms. In iron rich water and soil, these bacteria digest the iron in the lake water with the by- product of what is known as a bio-film and presents as an iridescent oil sheen on the surface of the lake water and in the small pools at the water’s edge. These iron-oxidizing bacteria are very prevalent in our area and wherever there is a high concentration of iron in the environment.

These types of biofilms are prevalent in nature, including pristine environments and most notably on our own bodies. Southern New Jersey and the Medford area are particularly known for high-iron water and soil. It is also iron that considerably stains the water to give it the “tea” appearance much more than the cedar trees that are often used to describe “cedar water.”

Incidentally, it is the iron prevalent in the water that our area was known for in colonial times. The iron was actually harvested from the local lakes and known as “bog iron” and then smelted in the local furnaces such as Taunton, Atsion or Aetna Forges to manufacture finished iron products for general use, including cannonballs used in the revolutionary war.

Regarding gas powered outboard engines on our lake

Although gas powered engines are not permitted for general recreation use, we do have contractors who occasionally need to be on the lake and use gas powered engines. This is not a cause for alarm, especially with concern for oil or gas contamination. It is exceedingly unlikely that any reasonably maintained outboard gas engine would leave oil or gasoline on the water during occasional use.

More Reading and background

Great piece from Indian Mills Historical Society about the bog iron industry at Atsion with pictures of iron oxide film from local streams

https://imhs2019.com/the-bog-iron-industry/

Iron Production in the New Jersey Pines

https://www.njpinebarrens.com/towers-of-fire-iron-production-in-the-new-jersey-pine-barrens/

Iron Oxidizing Biofilm in Pristine Environments

https://www.cs.montana.edu/webworks/projects/stevesbook/contents/chapters/chapter001/section004/blue/page002.html

Iron Oxidizing Bacteria General Info Wikipedia

https://en.wikipedia.org/wiki/Iron-oxidizing_bacteria

Technical literature “Iron Oxidizing Bacteria

https://www.microbiologyresearch.org/docserver/fulltext/micro/157/6/1551_mic045344.pdf?expires=1616328553&id=id&accname=guest&checksum=028EC0E0305F81B189E412284D25EE62




Is the lake water tested?


The lake water quality is tested weekly during the summer season to ensure it is safe for swimming. It is not frequent, but occasionally the count goes over the limit, often after a heavy rain and runoff, and we notify everyone that the beach is closed. We then test again the next day and generally the problem has been resolved.




Why is the lake not the same as it was years ago?


Our lake, Oliphant Lake, is actually a shallow dammed up branch of the Rancocas Creek watershed, originally built in 1955. The lake has become shallower in places due to accumulation of silt, leaves and other materials, and other natural forces. It is fed by other branches of the watershed, including from Lake Pine and Birchwood Lakes. The lake is the habitat of various vegetation and wildlife, resulting in a delicately balanced ecosystem that can be disturbed by factors such as lawn fertilization run-off and incorrect methods or application of vegetation control. More history on the dam and the lake can be found here. The Pennoni engineering report can be found here.