
(source: Town of Orleans Freshwater Ponds, Water Quality Monitoring Database: Development and Review. Coastal Systems Program, 2017. School for Marine Science and Technology, University of Massachusetts Dartmouth. New Bedford, MA. 216 pp. E. Eichner and B. Howes.)
Viewed from above, the Cape Cod peninsula is dotted with hundreds of freshwater ponds and lakes. These were formed in the depressions left in the land surface when the glaciers retreated, over 15,000 years ago. As these depressions filled with fresh water they became the ‘kettle ponds’ of Cape Cod.
Orleans has 60 freshwater ponds, 20 of which are named ponds. They range from small wooded vernal (seasonal) pools to four ‘Great Ponds’ that are over ten acres in size (Cedar Pond, Bakers Pond, Pilgrim Lake and Crystal Lake).
Our sparkling (and sometimes not so sparkling) freshwater ponds have been called the soul of the Cape, the eye revealing the groundwater (aquifer) below. We enjoy these ponds for swimming, fishing, kayaking and canoeing, bird watching and observing nature. Year round, they are places of peace and contemplation. Our ponds and lakes are also important parts of the Cape Cod ecology, providing habitat for a diversity of aquatic flora and fauna. Good water quality is vital for a healthy pond ecosystem and the many environmental services a pond provides. However, pond health and water quality have been negatively impacted in the past decades and continue to be threatened. The increase in population on Cape Cod and intensification of human activities in and around ponds have expanded and accelerated threats to pond health
The water quality of our ponds and lakes
The ponds and lakes of Orleans are fragile, as are those of all Cape Cod. The most recent (2024) State of the Waters report from the Association to Preserve Cape Cod ( https://capecodwaters.org/) concluded that of 15 evaluated (‘graded’) ponds in Orleans, 10 had unacceptable water quality and only 5 had acceptable quality. The Town of Orleans has also assessed several ponds and has similar conclusions: (https://www.town.orleans.ma.us/1654/NewWater-QualitySummaries-2002-2023). The cause of this poor quality is primarily excessive nutrient pollution (nitrogen and phosphorus) which results in eutrophication, cyanobacteria blooms, poor water clarity and low oxygen concentrations in water. These nutrients originate largely from human sources, primarily septic systems, fertilizers and untreated stormwater runoff.
What is the Town doing?
Since 2000, the Town of Orleans has coordinated a team of citizen volunteers who monitor water quality in twenty named ponds. This monitoring has provided data to support development of pond management plans for a number of ponds, with recommended actions to improve the water quality (https://www.town.orleans.ma.us/944/Management-Plans). A number of the pond-specific recommendations are being or have been implemented, including alum treatments to Uncle Harvey’s Pond (2021), and Crystal Lake and Pilgrim Lake (2024) to reduce phosphorus concentrations in the water, which caused cyanobacteria blooms.
Additionally, the Town has embarked upon a decades long project to implement a wastewater collection and wastewater treatment system. This new infrastructure will serve to significantly reduce the amount of nutrients seeping from septic systems, via groundwater to our ponds and coastal waters. This will provide a big boost to the recovery of the water quality and ecology of our waters.
What is OPC doing?
Since 2021, OPC has partnered with APCC to provide cyanobacteria sampling of six major lakes and ponds in Orleans. The goal of this initiative, which is fully funded by OPC, is to monitor and document the occurrence of cyanobacteria blooms and raise public awareness of the health and ecological risks they pose. These blooms can produce toxins, which are harmful to fish, shellfish, pets and humans. Recreational exposure to toxic cyanobacterial blooms via direct skin contact, inhalation, or inadvertent ingestion of water can cause rashes, allergies, and gastrointestinal problems and can be fatal if ingested by pets. The Town Health Department posts health warnings and swimming advisories based on the cyanobacteria monitoring results, as necessary. OPC also posts these warnings on its website. Additional goals are to help inform proper responses to cyanobacteria concerns, to promote public health, and perhaps most importantly, to motivate public action to address the causes of harmful cyanobacteria blooms by actively working to improve water quality. More information about the cyanobacteria monitoring and a summary of monitoring results from 2019-2024 are available at:
OPC will continue to advocate for the health of specific ponds.
Table 1 General Information Orleans freshwater ponds

Notes:
[1] Area and Depth values from: ‘2018, Town of Orleans Ponds and Lakes Monitoring Program, Quality Assurance Project Plan 2018-2020’, p. 11/48. Depth is at the deepest point, also water quality sampling location.
[2] Area and Depth values from: ‘2017, Town of Orleans Freshwater Ponds, Water Quality Monitoring Database: Development and Review; Coastal Systems Program, SMAST, Umass Dartmouth. New Bedford, MA. 216 pp. Eichner, E and B. Howes’ Note: Water levels in all ponds vary throughout the year, also influencing the surface area. All ponds are fed by groundwater and reflect the groundwater levels in Orleans. In later summer, water levels are typically at their lowest levels, and as a result pond shorelines have retreated, resulting in smaller surface areas.
[3] ‘Water Access’ implies the general public can have direct access to the water for recreation (e.g. swimming, boating, fishing). At most ponds with water access, the access if via Town owned land. However, at a few ponds, there is water access via Orleans Conservation Trust (OCT) walking trails.
[4] Crystal Lake and Pilgrim Lake are Official Town Beaches. These lakes are monitored for bacteria levels for swimming water quality by the Orleans Department of Health and posted if not found acceptable. Additionally, OPC monitors these two lakes for cyanobacteria (as well as Baker, Boland, Cedar, and Uncle Harvey’s Ponds) and reports any negative findings to the Department of Health.
[5] The Town of Orleans and Orleans Conservation Trust (OCT) have walking trails along several ponds.
[6] Baker’s Pond, Crystal Lake and Pilgrim Lake have fisherman’s boat ramps or lake access for boat trailers; At other fishing ponds it is possible to carry a kayak or canoe to the water. For all motorized boats, there is a maximum limit of 5 HP, electric motors only.
[7] Fisheries: Crystal and Baker’s Ponds are Cold Water Fisheries; both are stocked by MA Fisheries and Wildlife in spring & fall with brook, brown and rainbow trout. All other ponds are warm water fisheries and primarily have largemouth and smallmouth bass, yellow perch and pickerel; Fishing is allowed on the ponds where OCT trails provide water access. A MA state license is required for all fresh and salt water fishing (www.mass.gov/buy-fishing-or-hunting-licenses).
[8] Cedar Pond is not technically a freshwater pond as it has a tidal connection to Rock Harbor estuary (i.e. brackish), but is listed here among other ‘inland ponds’; The water level in Cedar Pond is artificially influenced by wooden boards for regulating the tidal flow from Rock Harbor.
Table 2 Regulatory Information Orleans freshwater ponds

Notes:
[9] A ‘Great Pond’ is > 10 acres and must meet water quality requirements defined by Mass. DEP (Dept of Environmental Protection).
[10] All Orleans ponds are located within one of three watersheds (Rock Harbor, Nauset Marsh or Pleasant Bay). These are the coastal areas into which the ponds ultimately flow, via groundwater flow (See Figure 2, groundwater flow map).
[12] ACEC: Areas of Critical Environmental Concern are places in Mass that receive special recognition because of the quality, uniqueness and significance of their natural and cultural resources. ACECs have higher environmental regulatory oversight and state permitting standards than other areas. (Link). The ponds having a direct hydrological connection to coastal ACECs such as Pleasant Bay and inner Cape Cod Bay are also defined as ACECs.
[13] Priority Habitat is based on the known geographical extent of habitat for all state-listed rare species, both plants and animals, and is codified under the Mass Endangered Species Act (MESA).
Town of Orleans Pond Management Plans
[14] 2022. Baker Pond Management Plan and Diagnostic Assessment. Town of Orleans, Massachusetts. Coastal Systems Program, School for Marine Science and Technology, University of Massachusetts Dartmouth. New Bedford, MA. 106 pp. E. Eichner, B. Howes, and D. Schlezinger.
[15] 2013. Cedar Pond Water Quality Management Plan. Coastal Systems Program, School for Marine Science and Technology, University of Massachusetts Dartmouth. New Bedford, MA. 54 pp. E. Eichner, B. Howes, and D. Schlezinger.
[16] 2021. Crystal Lake Management Plan and Diagnostic Assessment. Town of Orleans, Massachusetts. Coastal Systems Program, School for Marine Science and Technology, University of Massachusetts Dartmouth. New Bedford, MA. 104 pp. E. Eichner, B. Howes, and D. Schlezinger.
[17] 2019. Pilgrim Lake Management Plan and Diagnostic Assessment. Town of Orleans, Massachusetts. Coastal Systems Program, School for Marine Science and Technology, University of Massachusetts Dartmouth. New Bedford, MA. 114 pp. Eichner, E., B. Howes, and D. Schlezinger. [18] 2018. Uncle Harvey’s Pond Management Plan and Diagnostic Assessment. Town of Orleans, Massachusetts. Coastal Systems Program, School for Marine Science and Technology, University of Massachusetts Dartmouth. New Bedford, MA. 106 pp. Eichner, E., B. Howes, and D. Schlezinger.
What can you do as a resident?
Property owners play a vital role in maintaining the quality of our ponds. Pond abutters are responsible for maintaining a vegetated natural buffer along the water’s edge – preferably native vegetation, with a width of at least 50 feet. This vegetation helps to absorb runoff and nutrients flowing toward the pond. All homeowners should adopt a ‘Cape Cod Lawn’ fertilized only by grass clippings or use natural, native ground covers that do not require fertilization or irrigation. We encourage all Orleans homeowners to take the H2Orleans Pond Pledge to:
- Avoid Fertilizers and Pesticides
- Support Town Sewering Efforts
- Embrace a Cape-Friendly Lawn