Rice Lake

Where Rice Lake is

Rice Lake lies in the County of Northumberland and the County of Peterborough, with shoreline in the Township of Alnwick/Haldimand, the Township of Hamilton, the Township of Asphodel-Norwood and the Township of Otonabee-South Monaghan.

How deep is Rice Lake?

The deepest mapped contour on Rice Lake is 9.0 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 248 depth contours for Rice Lake.

Surveyed Depths

Ontario has surveyed the depths of several thousand of its lakes over more than half a century. Later surveys were conducted by boat with satellite positioning and produced hundreds of thousands of soundings per lake. Earlier surveys were charted by running transects across the water and drawing depth contours by hand.

Water quality

Ontario’s Lake Partner Program is a volunteer monitoring network. Participants collect a water sample each spring for phosphorus analysis and measure water clarity through the summer with a Secchi disk.

Phosphorus is the nutrient that controls how much algae a lake can grow. A lake with little phosphorus stays clear and supports cold-water fish such as lake trout. As phosphorus rises, algae increase, the water clouds, and oxygen in the deep water falls as the algae decay. The province classifies each monitoring site by its spring phosphorus. Below 10 micrograms per litre is oligotrophic: clear water and low algae. From 10 to 20 is mesotrophic: moderately productive water, with more algae and weed growth than an oligotrophic lake but rarely a bloom. Above 20 is eutrophic: nutrient-rich water, prone to algal blooms and low oxygen at depth.

A Secchi disk is a 20 centimeter white or black-and-white plate lowered on a marked line until it disappears from view. The depth at which it vanishes is the Secchi depth, a direct measure of water clarity. Clearer water gives a deeper reading.

Rice Lake has 6 Lake Partner monitoring sites. One of them has reported phosphorus for the three or more years the province requires before a status is assigned, and is classified eutrophic.

The longest record is held by site 6920/34 at Stn 34 Spook Is., sampled over 4 springs to 2008. Its long-term mean phosphorus concentration is 23.42 micrograms per litre, within the eutrophic band, which begins at 20. The site’s 14 clarity readings give a median Secchi depth of 1.5 meters.

Water temperature

Ontario’s aquatic resource records class Rice Lake as a warm-water lake, with a mean depth of 2.6 meters against its maximum of 9.

A lake separates into layers through the summer where it is deep enough. Sunlight and wind warm and mix the upper few meters, and beneath a band of rapid cooling, the thermocline, the water stays cold. A shallow lake mixes to the bottom instead and warms through, sooner in spring and later into autumn.

No provincial monitoring station records water temperature on Rice Lake. The province’s longest in-water record is kept on eight research lakes near Dorset, sampled since 1976. A reading is taken at the surface, at one meter, at each meter to seven and then every two meters to the bottom, about every two weeks through the open-water season and about monthly under ice. The record holds 5,240 readings at a depth of one meter.

At one meter the eight lakes track one another closely. On a day when several were sampled, the warmest and the coolest lake differed by about one degree in every month of the year, and a 12 meter deep lake and a 37 meter deep lake read within 0.2 degrees of each other from June to October. The weather of the year, and not the lake, sets most of the width of the band below.

Satellite thermal imagery gives a surface reading on clear days: the Landsat sensors pass over Rice Lake every eight days at a resolution of 100 meters. In the province’s record the surface reading and the one meter reading agree to within half a degree nine times in ten in summer.

The water a few meters down is colder than any figure on this chart, in every month of the year.

How depth changes the temperature

The chart below is the province’s record on Harp Lake, 37 meters deep, drawn as the median temperature at each depth for each month over 49 years. In July the water at one meter is 23 degrees, at five meters 15, at seven meters 9, and from 13 meters to the bottom under 6. By October the warm layer has deepened to seven meters and cooled to 11 degrees. In February the whole column sits between 1 and 4 degrees under the ice, coldest at the top.

A shallower lake in the same record warms sooner. Heney Lake, six meters deep, reads about 1.8 degrees warmer than Harp Lake at one meter from January to May, 0.8 degrees warmer from June to August, and the same or cooler from September.

Fish in Rice Lake

Ontario’s aquatic resource records name 36 fish species in Rice Lake. The province classes the lake as warm water. The record took effect on 15 August 2018, and it compiles what field biologists had reported by then.

Fourteen of the 36 species in the province’s records

• Northern Pikepike
• Muskellungepike
• Walleyeperch
• Yellow Perchperch
• Smallmouth Basssunfish
• Largemouth Basssunfish
• Black Crappiesunfish
• Rock Basssunfish
• Pumpkinseedsunfish
• Bluegillsunfish
• Burbotcod
• Brown Bullheadcatfish
• Common Carpminnow
• Lake Sturgeonother

Spawning areas

Ontario maps 101 fish spawning records within the Rice Lake outline, for four species, all of them mapped areas.

By number of records

By area mapped

• Smallmouth Bass43 areas104.6 ha
• Muskellunge21 areas703.5 ha
• Largemouth Bass20 areas193.2 ha
• Walleye17 areas4.0 ha

The federal Fisheries Act prohibits the harmful alteration, disruption or destruction of fish habitat without an authorization, so a dock, dredging, infill or shoreline work at a mapped spawning area is reviewed on that basis.

Stocking history

Ontario’s stocking records for Rice Lake run from 1946 to 1990 and hold 164 releases. Muskellunge account for most of the fish: 4,280,789 released in 44 of the years between 1946 and 1990. The last recorded release was 100,000 muskellunge frys in 1990.

The province’s current stocking programme, recorded from 2016, lists no release into Rice Lake.

Eating the fish

The 2025 Guide to Eating Ontario Fish carries consumption advice for thirteen species taken from Rice Lake, tested for contaminants at a sampling location in off Otonabee River, Peterborough Co. Each figure below is the most meals a month the guide advises for a fish of that length. The advice falls as the fish gets longer, because mercury accumulates over a fish’s life. A zero means the guide advises no meals of that fish at that size.

General population adultsSensitive population children under fifteen, women who are or may become pregnant

Fisheries Management Zone 17

Rice Lake lies in Fisheries Management Zone 17. Ontario sets its fishing seasons and catch limits by zone.

The figures are the number of fish an angler may catch and keep in a day and have in possession, under a sport fishing licence and under a conservation licence. The rows are the whole zone’s, and they apply to every lake in it. No waterbody exception names Rice Lake.

Rice Lake Ice Fishing

An ice hut on Rice Lake must be removed by March 1. Rice Lake lies in fisheries management zone 17, one of the twenty zones Ontario sets its fishing rules by, and one removal date applies across the whole zone.

An ice hut must also be removed before the ice breaks up, whether or not that date has passed. The deadline clears huts from the ice ahead of the thaw and does not close the fishing season.

Registration is required in zone 17 for an ice hut built of anything other than fabric, and for a fabric tent covering seven square meters or more. Registration is free, and the number is displayed on the outside of the hut.

When the ice goes out

The ice has been recorded leaving Rice Lake at Indian River in 34 springs between 1969 and 2002. The median date is April 11. The earliest recorded break-up is February 11 in 1981, and the latest is May 1 in 1972.

Across the 34 recorded springs the date has moved earlier by about 2.9 days each decade.

The record was contributed by Martyn N. Futter to the Global Lake and River Ice Phenology Database. It holds the day the ice left and carries no date for the day it formed, so it says nothing about when Rice Lake freezes.

Ice conditions

No public record reports the thickness or the condition of the ice on Rice Lake on any given day. Ontario publishes ice safety guidance for anyone going out on the ice, at ontario.ca.

Islands and names

Rice Lake contains 44 islands in the Ontario Hydro Network’s outline, eight of them over 10 hectares and fourteen under a tenth of a hectare. Twenty-three of them lie inside wetlands mapped in the province’s Wetland With Significance dataset. The largest two, of 9.8 and 2.7 hectares, fall inside the Hiawatha wetland.

Official names

Ontario’s geographic names register lists 35 official names on the water and its islands: 22 islands, four bays, two shoals, two points on islands and one river. A further 18 named points stand on the mainland shore. The register records the origin of three names.

Bays 4

• Burrison's Bay
• McGregor Bay
• Morrow Bay
• Webb Bay

Shoals and rocks 2

• Hiawatha Shoal
• Sunken Island

Points on the shore 18

• Birdsalls Point
• Cameron Point
• Curtis Point
• Foley Point
• Hatrick Point
• Herkimer Point
• Idylwilde Point
• Jubilee Point
• Ley Point
• Morrow Point
• Picnic Point
• Pine Tree Point
• Plum Point
• Roach Point
• Sager Point
• Sand Point
• Shearer Point
• Wallace Point

Nearby lakes

• Chemong Lake31 km away
• Clear Lake37 km away
• Buckhorn Lake39 km away
• Pigeon Lake40 km away

All lakes

Questions about Rice Lake

• How deep is Rice Lake?

  Its deepest charted contour is 9 meters, and the water within it is deeper.

• How big is Rice Lake?

  Its surface covers 92.3 square kilometers and it holds 44 islands. Of its 167 kilometers of shoreline, 121 kilometers is the mainland shore and 46 kilometers is the shore of the islands.

• What fish are in Rice Lake?

  Ontario’s aquatic resource records name 36 species, among them walleye, smallmouth bass, largemouth bass, northern pike, muskellunge and yellow perch.

• Is the water clear?

  The one monitoring site with a phosphorus status is classified eutrophic, the most nutrient-rich of the province’s three bands.