Laoyaba Reservoir

Overview

Laoyaba Reservoir lies in Baima Town, Lishui District, and is one of the district's six medium-sized reservoirs (Nanjing Municipal Water Resources Bureau, March 2022; district government natural resources page; Jiangsu Water Resources, 2022 no. 5). Its class is medium: the Nanjing Municipal Water Resources Bureau's 2022 list of the "four responsible persons" for reservoirs gives Laoyaba Reservoir's scale as medium, its township as Baima Town, and its management unit as the Laoyaba Reservoir Management Office. The registered unit map of the Nanjing Municipal Planning and Natural Resources Bureau's register marks the registered unit as falling in Baima Town, in the various farmers' collectives of Bailong Community; "Baima Town, Bailong Community" is the administrative name of 2024.

Capacity: total capacity 1163 10,000 m³, usable capacity 487 10,000 m³ and usable water level 34.8 m (Jiangsu Water Resources, 2022 no. 5, Table 2). This entry's capacity_10k_m3 takes the total capacity of 1163 10,000 m³. No second figure for the total capacity has been found on this site, nor any figure for the flood-control or dead capacity.

Area: the Natural Resource Register of the Nanjing Municipal Planning and Natural Resources Bureau, entered on 14 June 2024, records in the water-flow table of the registered unit Laoyaba Reservoir a water surface of 157.40 ha for "reservoir surface — Laoyaba Reservoir", covering two parcels; the water-flow row of the same register's natural conditions table also gives 157.40 ha. This entry's area_km2 takes the water surface of 157.40 ha, that is 1.574 sq km; the two rows are different fields, see Open questions.

Registered unit and boundaries: registered unit number 320117333000005, unit type "reservoir surface", situated in Lishui District, Nanjing, Jiangsu. Its boundaries are the Ninghang Railway to the east, the Xinqiao River to the south, an existing road to the west and the Hongju River to the north. The registered unit covers 274.38 ha in all, of which 188.75 ha is state-owned, 85.63 ha collectively owned and 0.00 ha disputed; the natural resources within the unit total 234.87 ha, namely 157.40 ha of water flow, 4.56 ha of wetland, 70.72 ha of forest and 2.19 ha of grassland, with a further 39.51 ha of non-natural-resource land such as cultivated land and built-up land.

Catchment: the Nanjing Municipal People's Government portal records that "click on 'catchment area' and you can see the extent of the 17.5 sq km catchment of Laoyaba Reservoir in Lishui District" (14 November 2024); Table 2 of Jiangsu Water Resources, 2022 no. 5, gives a catchment of 58.11 sq km. The two are shown side by side under Open questions, and this entry leaves the catchment field empty.

Basin recorded as Shijiu Lake: Laoyaba Reservoir is the source of the Xinqiao River, and the Xinqiao River is an inflow river of the Shijiu Lake system (Jiangsu Provincial Department of Water Resources, 15 May 2024; Dongping Subdistrict Office environmental report, January 2020). No official document directly stating Laoyaba Reservoir's basin has been found on this site; the basis is set out under Open questions.

Names: the Jiangsu Provincial Department of Water Resources and the municipal and district water departments use Laoyaba Reservoir, while the Dongping Subdistrict Office environmental report writes Laoyaba Reservoir with a variant first character; the two refer to one water body, and this entry uses Laoyaba Reservoir throughout, with the variant noted under Open questions.

Formation and change

Relation to the source: the Dongping Subdistrict Office environmental report records that "the Xinqiao River has its source at Laoyaba Reservoir, runs across Baima and Jingqiao towns, reaches the north of Kongzhen and discharges into Shijiu Lake by Changtang village, 26.28 km in all"; the Jiangsu Provincial Department of Water Resources records that "the Xinqiao River rises at Laoyaba Reservoir, flows into Shijiu Lake, about 31.4 km in all". The southern boundary of the register's four boundaries is the Xinqiao River, which fixes the spatial relation between Laoyaba Reservoir and the Xinqiao River, but a boundary description is not the same as "the reservoir stands on the Xinqiao River". The northern boundary is the Hongju River, and no source has been found on this site for that river's ends, direction or basin.

Works management: Laoyaba Reservoir is under district management. Article 3 of the Measures for the Management and Protection of Water Conservancy Works in Lishui District lists seven district-managed reservoir management offices, including the Laoyaba Reservoir Management Office; Article 19(1) records that its maintenance funds are budgeted by the district finance bureau. A cross-check flood level of 37.52 m (Wusong datum) is given in the district water bureau's and Jingqiao Town government's reply to suggestion no. 038 of the district people's congress, quoting that instrument.

Operation and management pilot: in 2024, six reservoirs including Laoyaba were listed among the national pilot projects for the modernised matrix of reservoir operation and management; Laoyaba Reservoir was the first to build a reservoir operation and management matrix information platform, with 102 smart boundary posts set up within its management boundary, the management unit being the Laoyaba Reservoir Management Office (Nanjing Municipal People's Government portal, 14 November 2024). That item is a news report carried by the government portal and sourced from Nanjing Daily, not a departmental document.

Reinforcement and ecological restoration: the plan records that during the Twelfth Five-Year period the reinforcement of six medium-sized reservoirs in the district, including Zhongshan and Fangbian, was completed (a district-wide total, with no year or content given for each); the 13th Five-Year tasks include comprehensive water-environment improvement, water-quality monitoring and ecological wetland restoration on the inflow channels of the four medium-sized reservoirs Laoyaba, Yaojia, Zheshantou and Wolong (Lishui District Water Development 13th Five-Year Plan, the latter being a plan-task statement and not written here as completed).

Drinking water source area and ecological space: Laoyaba Reservoir is one of the drinking water source areas (Jiangsu Water Resources, 2022 no. 5; the drinking water function area list in the 13th Five-Year plan includes Fangbian, Zhongshan, Laoyaba, Yaojia and Zheshantou but not Wolong). The Lishui District Finance Bureau's 2020 ecological space protection area table records a "Laoyaba Reservoir drinking water source conservation area" of 10.41 sq km; the 2025 draft plan for evaluating and optimising ecological space control areas records a "Laoyaba Reservoir water source conservation area" of 1034.2031 ha. The latter is a draft for comment, not an instrument in force.

No first-tier source has been found for the year Laoyaba Reservoir was built or for a reservoir-by-reservoir list of reinforcement works, so nothing is written here.

Landscape and visiting

Woodland and wetland in the reservoir area: the register records 70.72 ha of forest within the registered unit, namely 98 parcels of other woodland totalling 69.05 ha, one parcel of high forest of 1.0 ha, one parcel of bamboo of 0.56 ha and one parcel of shrub land of 0.11 ha, the other woodland having a standing volume of 8152.46 cubic metres with walnut and moso bamboo as the main species; 4.56 ha of wetland in eight parcels of inland mudflat; and 2.19 ha of grassland in ten parcels of other grassland. These are the natural conditions on the confirmed registration basis, not a scenic area's extent or opening information.

Water quality statistics: Jiangsu Water Resources, 2022 no. 5, takes the six medium-sized reservoirs of Lishui District as its subject and gives monthly water quality statistics for Laoyaba Reservoir from 2011 to 2021, assessed on total phosphorus and total nitrogen: class II 15.9%, class III 65.9%, class IV 17.4%, and class V and worse 0.8%, the last occurring in 2012. Those proportions are ratios from monthly statistics for 2011 to 2021, not a water quality conclusion for any one year; the paper also assesses the eutrophication trend, and this site records only the subject of the study and the period of its statistics without restating evaluative judgements.

Visiting information: no first-tier source has been found for public visiting, a lakeside footpath, viewing facilities or tickets at Laoyaba Reservoir; the reservoir is a drinking water source area, and visiting information should follow the official notices of the district water department, the district culture and tourism department and the local town. Opening information is current to September 2026.

Open questions

• Two catchment figures: 17.5 sq km (Nanjing Municipal People's Government portal, 14 November 2024, restating the figure shown on the modernised reservoir operation and management matrix platform) and 58.11 sq km (Jiangsu Water Resources, 2022 no. 5, Table 2). Neither source states whether "catchment area" in the two senses is the same thing, and the two may not be equated outright; the catchment column in Table 2 of Jiangsu Water Resources gives very close figures for four reservoirs and cannot be reconciled with the 303.54 sq km total catchment of the county's 79 reservoirs in the Lishui County Eleventh Five-Year Water Plan, and no second source has been found, so this site does not adopt the figure on its own and leaves the catchment field empty.
• Two area rows: the register's water-flow table "reservoir surface — Laoyaba Reservoir" 157.40 ha and the natural conditions table's water-flow row 157.40 ha are two fields, and the figures happen to agree; this entry's area_km2 takes the former, and any citation must state which row is meant. The registered area is the water-flow range on the confirmed registration basis and is not the same statistical range as the reservoir's designed water surface.
• Only one source for the capacity: the total capacity of 1163 10,000 m³ and usable capacity of 487 10,000 m³ in Jiangsu Water Resources, 2022 no. 5, Table 2, have no equivalent figure from the water authority on this site; the table gives only total and usable capacity, which are not the same set as the flood-control and dead capacities of Fangbian and Zhongshan in the district people's congress reply, and the two may not stand in for one another.
• No direct source for the basin: this entry's basin records Shijiu Lake, on the ground that the Xinqiao River rises at Laoyaba Reservoir and flows into Shijiu Lake and that Laoyaba Reservoir is the source of the Xinqiao River; no official document directly stating Laoyaba Reservoir's basin has been found on this site.
• Variant spelling: the Jiangsu Provincial Department of Water Resources and the municipal and district water departments use Laoyaba Reservoir, while the Dongping Subdistrict Office environmental report uses a variant first character; the two refer to one water body, and this entry uses Laoyaba Reservoir throughout.
• Year of construction: neither the register, the water bureau's list nor the paper in Jiangsu Water Resources gives a year of construction, and no year of construction or document number of class approval for Laoyaba Reservoir has been found, so none is written.
• The Hongju River: the northern boundary of the register's four boundaries is the Hongju River, and no source has been found on this site for its ends, direction or basin, so nothing may be inferred from the boundary description.
• Boundary names: the register's four boundaries give "the Ninghang Railway to the east, an existing road to the west" and names ending in "line"; the register treats these as boundary descriptions only and does not say whether they are roads or boundary lines, so they are quoted as they stand without inference.
• The "catchment of 17.5 sq km" comes from a news report carried by the government portal and sourced from Nanjing Daily, not a departmental document; the same item's "250 registered reservoirs in Nanjing, 13 of them medium-sized" is that report's city-wide annual figure, different from the district list, and the two must not be mixed.
• The cross-check flood level of 37.52 m (Wusong datum) reaches us through the district water bureau's and Jingqiao Town government's reply to suggestion no. 038 of the district people's congress, quoting the Measures for the Management and Protection of Water Conservancy Works in Lishui District; that reply has Zheshantou Reservoir as its subject, so any citation must state that it is the reply's quotation of the instrument and must mark it separately from Zheshantou Reservoir's Qingdao datum level.
• The number of medium-sized reservoirs in the district is given as six (district government natural resources page) and as seven (14th Five-Year Water Plan); the latter does not name them, and this site does not supply a name for the seventh.